Air is blowing out (Leaking) from under the Equipment's Heater Box
Re-caulking Supply and Return Air Collar Connections up to 900°F
Inspect the Return and Supply Duct connections to determine if there is any air leakage. If you can feel
air movement between the heater box and the roof panels on the outside of the unit, the seal has failed.
Supply Duct Connection
Return Duct Connection
Curing the Caulking
We hope you will find this information useful. THANK YOU for contacting us and allowing us to be a
service to you. Please contact us at 1-800-473-7373 if you have any questions.
Conversions and Modifications to your Equipment
The information that you are looking for is not readily available and requires us to search through our records to determine the required design change(s), and the material(s) needed.
We would be happy to research the information requested. Generally most requests can be researched within one (1) to two (2) hours, but if the actually time required is greater, a research fee may be required to cover the costs incurred. We will respond within three (3) to five (5) business days of receipt of a copy of your purchase order or a written acknowledgment of our rates (by fax or mail).
We will require that you provide us a detailed description of the desired changes or modifications, including the process specifications. Examples: Process Temperature(s), Work Chamber Temperature Uniformity, Solvent Level(s), Product Volume(s), etc.
Example #1 Convert gas fired system from propane to natural gas. Generally this change will require:
Example #2 Convert electric heated system for 220/240 volts to 460/480 volts. Generally this change will require:
Replacement original equipment operating instruction manual are available through our Parts Department at 1-800-473-7373 Option #2. The cost is not based on the material content, but time required to research and assemble the replacement manual. On standard models the cost for a replacement manual will generally range from $200 to $400. On special or large engineering system equipment, a review of the equipment would be needed to determine the replacement manual cost.
We hope you will find this information useful. THANK YOU for contacting us and allowing us to be a service to you. Please contact us at 1-800-473-7373 if you have any questions.
The information that you are looking for is not readily available and requires us to search through our records to determine the required design change(s), and the material(s) needed.
We would be happy to research the information requested.. Generally most requests can be researched within one (1) to two (2) hours, but if the actually time required is greater, a research fee maybe required to cover the costs incurred. We will respond within three (3) to five (5) business days of receipt of a copy of your purchase order or a written acknowledgment of our rates (by fax or mail).
We will require that you provide us a detailed description of the desired changes or modifications, including the process specifications. Examples: Process Temperature(s), Work Chamber Temperature Uniformity, Solvent Level(s), Product Volume(s), etc.
Example #1 Convert gas fired system from propane to natural gas. Generally this change will require:
Example #2 Convert electric heated system for 220/240 volts to 460/480 volts. Generally this change will require:
Replacement original equipment operating instruction manual is available through our Parts Department at 1-800-473-7373 Option #2. The cost is based on the time required to research and assemble the replacement manual. On standard models the cost for a replacement manual will generally range from $200 to $400. On special or large engineering system equipment, a review of the equipment would be needed to determine the replacement manual cost.
PROCESS QUESTIONNAIRE |
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YOUR COMPANY NAME: |
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ADDRESS: |
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YOUR NAME: |
TITLE: |
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PHONE #: |
FAX#: |
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EQUIPMENT: |
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SERIAL NUMBER: |
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MODEL NUMBER: |
PROCESS: (Describe, in detail, the process supported by the Despatch equipment identified above.)
...USE SEPARATE PAGE IF REQUIRED
HOW LONG ARE PARTS IN OVEN?___________PROCESS TEMP _____________________(Process Duration)
DOES YOUR PROCESS INVOLVES VOLATILES? YES____NO____
Volatile Name |
Lbs/Hour |
Gal/Hour |
Lbs/Gal |
CFBE* |
|
||||
|
||||
|
*CFBE = Cubic Feet of Air Rendered Barely Explosive per Gallon of Solvent
(IMPORTANT: We Must Know Exact Amount of Volatile Used or Released)
DOES PROCESS CONTAIN OTHER COMBUSTIBLES? WHAT TYPE?
ELECTRICAL SAFETY SYSTEM:
Exhaust Fan and Proper Airflow Sensor Present? Working?
Purge Timer? High-Limit Control Installed & Working?
Electric Heat Back -Up Contractor Installed & Working?
Voltage: Heaters?_______Motors?_______Controls?_________
AIR HANDLING SYSTEM:
Fresh Air Duct Size?_______(ID)Damper Blade Size?_______Open Area?_________
Exhaust Duct Size? (ID)Damper Blade Size? Open Area?
PROCESS QUESTIONNAIRE
POWDER COATING ONLY
Powder Coating Processes create special concerns for the safe operation of your Despatch equipment. The following request for information will help Despatch determine if your equipment and process are compatible. If a problem is detected we will notify you at once. Until we have had the opportunity to review the following information we must advise you of the following warning.
WARNING: IMPROPER USE OF THIS EQUIPMENT CAN RESULT IN PROPERTY DAMAGE, SERIOUS BODILY INJURY OR DEATH!
DO NOT USE THIS EQUIPMENT UNTIL YOU ARE CERTAIN THAT YOUR PROCESS IS COMPATIBLE WITH THE EQUIPMENT DESIGN.
Please Answer The Following:
Surface area of the maximum load of parts processed in an hour, expressed in (Square Feet per Hour) Square Feet /Hour.
Maximum Powder Thickness? Mils.
What are the Powder Manufacturer's Recommended coverage in square feet per pound to yield a coating 1 Mil thick? square feet per pound
We hope you found this information useful. THANK YOU for contacting us and allowing us to be a service to you. Please contact us at 1-800-473-7373 if you have any questions.
Each application is different as is each piece of equipment is different, making a standard Preventive Maintenance (PM) program impossible. We at Despatch can research and develop a PM program for your equipment and application.
Sample PM Schedule
Item Description |
Reading or Setting |
Months Of Operation |
||||
|
|
1 |
3 |
6 |
9 |
12 |
Measure and record the line and control voltages — if the voltage is +/-10% of the specification on the equipment nameplate discontinue use and take corrective action. |
L1= |
|
|
|
|
X |
Measure and record recirculation fan motor amps — will give a rough indication of fan efficiency, a reduction in motor amps of more than 15% at ambient temperature, could indicate improper loading or a restriction in the recirculation blower fan or duct work. |
T1= |
|
|
|
|
X |
ALTERNATIVES - After the program is defined per above.
We hope you will find this information useful. THANK YOU for contacting us and allowing us to be a service to you. Please contact us at 1-800-473-7373 if you have any questions.
Available Subjects:
Objective of Course:
To train operators or maintenance personnel on procedures required to:
Course Structure and Duration:
Course Deliverables:
Prerequisites:
Warning: Improper setup and operation of this equipment could cause an explosion that may result in equipment damage, personal injury or possible death.
To place an order for training, please fax a copy of your purchase order or a written acknowledgment of our rates, authorizing service to (612) 781-5485.
We hope you will find this information useful. THANK YOU for contacting us and allowing us to be a service to you. Please contact us at 1-800-473-7373 if you have any questions.
The Cooling Coils are designed to be used with a gravity drain, which is designed to empty the coil when the equipment is being heated above 200°F. The coil must be empty during the heating process. This is to reduce the steam generated in the coil and the build-up of deposits inside the coil.
This is accomplished by using a vacuum breaker and check valve on the coil outlet and a flow meter and solenoid valve(s) on the coil inlet. The drain line(s) should be insulated or labeled with a warning label indicating that a high temperature hazard exists.
The LCC and LND Series models can use the Cooling Coil Kit #090020 for adding the components and using the Protocol Controller to automatically energize the solenoids with an Event in a temperature profile/recipe.
WARNING STEAM BURNS - Never allow the drain to be plugged, as a hot oven will generate a small amount of steam.
Closed loop systems are not recommended as they do not remove the water from the coil during the heating cycle. One variation from the above method that could be used, is to have a sump tank to collect the water from the drain. Another variation is to discharge the water in the coil to the drain when the coil is not in the loop.
The Coils are typically designed to operate from 10 PSIG minimum to 99 PSIG maximum with a maximum water temperature of 60°F. The cooling performance at various flow rate will depend on the water temperature and the amount of cooling required.
We hope you will find this information useful. THANK YOU for contacting us and allowing us to be a service to you. Please contact us at 1-800-473-7373 if you have any questions.
The information that you need may not be readily available and would require us to search through our records. Typically much of the information is included within the equipment’s original operating instruction manual or listed on the Nameplate mounted on the equipment (usually on the control compartment door, or the rear of the equipment). This includes:
If you would like us to research additional information for you, we will be happy to fulfill your request, but first we must document that the equipment is being used in a proper way. As you know, product liability issues cost all of us far more than we would like. Therefore, in an effort to help reduce our exposure and thereby keeping our products competitively priced, we have a very strict policy with regards to insuring that the process is compatible with the equipment’s original design. We must therefore request that you answer a few simple questions about your process.
To help you with this request, we have included a PROCESS / MANUAL QUESTIONNAIRE.
WARNING: IMPROPER USE OF THIS EQUIPMENT CAN RESULT IN PROPERTY DAMAGE, SERIOUS BODILY INJURY OR DEATH!
DO NOT USE THIS EQUIPMENT UNTIL YOU ARE CERTAIN THAT YOUR PROCESS IS COMPATIBLE WITH THE EQUIPMENT DESIGN.
We must rely on your knowledge of the process. Despatch claims no knowledge of the details of your specific process. We can only determine if your Despatch equipment is compatible with your process based on the information we are asking you to provide. If an unsafe condition exists we will advise you to IMMEDIATELY SHUT DOWN YOUR Despatch EQUIPMENT Despatch can also assist you in modifying or replacing your present equipment to eliminate any hazard.
We will review the information received. Generally most requests can be researched within one (1) to two (2) hours, but if the actually time required is greater than this, a purchase order for an engineering fee will be required to perform the work. We will respond within three (3) to five (5) business days of receipt of a copy of your purchase order or a written acknowledgment of our rates (by fax or mail).
Replacement operating instruction manual or S-type installation manual are available through our Customer Service Group at 1-800-473-7373 Option #2 (parts).
The operating instruction manual contains:
The S-type installation manual contains:
We hope you will find this information useful.THANK YOU for contacting us and allowing us to be a service to you. Please contact us at 1-800-473-7373 if you have any questions.
PROCESS QUESTIONNAIRE |
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YOUR COMPANY NAME: |
||||
ADDRESS: |
||||
YOUR NAME: |
TITLE: |
|||
PHONE #: |
FAX#: |
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EQUIPMENT: |
||||
SERIAL NUMBER: |
||||
MODEL NUMBER: |
PROCESS:
(Describe, in detail, the process supported by the Despatch equipment identified above.)
USE SEPARATE PAGE IF REQUIRED
HOW LONG ARE PARTS IN OVEN?___________PROCESS TEMP_____________________(Process Duration)
DOES YOUR PROCESS INVOLVES VOLATILES? _____YES____NO
Volatile Name |
Lbs/Hour |
Gal/Hour |
Lbs/Gal |
CFBE* |
|
||||
|
||||
|
*CFBE = Cubic Feet of Air Rendered Barely Explosive per Gallon of Solvent
(IMPORTANT: We Must Know Exact Amount of Volatile Used or Released)
DOES PROCESS CONTAIN OTHER COMBUSTIBLES? WHAT TYPE?
ELECTRICAL SAFETY SYSTEM:
Exhaust Fan and Proper Airflow Sensor Present? Working?
Purge Timer? High-Limit Control Installed & Working?
Electric Heat Back -Up Contractor Installed & Working?
Voltage: Heaters?_______Motors?_______Controls?_________
AIR HANDLING SYSTEM:
Fresh Air Duct Size?_______(ID)Damper Blade Size?_______Open Area?_________
Exhaust Duct Size? (ID)Damper Blade Size? Open Area?
PROCESS QUESTIONNAIRE
POWDER COATING ONLY
Powder Coating Processes create special concerns for the safe operation of your Despatch equipment. The following request for information will help Despatch determine if your equipment and process are compatible. If a problem is detected we will notify you at once. Until we have had the opportunity to review the following information we must advise you of the following warning.
WARNING: IMPROPER USE OF THIS EQUIPMENT CAN RESULT IN PROPERTY DAMAGE, SERIOUS BODILY INJURY OR DEATH!
DO NOT USE THIS EQUIPMENT UNTIL YOU ARE CERTAIN THAT YOUR PROCESS IS COMPATIBLE WITH THE EQUIPMENT DESIGN.
Please Answer The Following: Surface area of the maximum load of parts processed in an hour, expressed in (Square Feet per Hour) Square Feet /Hour.
Maximum Powder Thickness? Mils.
What are the Powder Manufacturer's Recommended coverage in square feet per pound to yield a coating 1 Mil thick? square feet per pound.
It is highly recommended that this whole document be read carefully before handling filters.
Definitions
HEPA Filter = High Efficiency Particulate Air Filter. High means 99.97% or higher. The efficiency is a measure of how effectively the filter traps particles. It is calculated by dividing the number of particles trapped by the total number impinging on the filter. Fewer than 3 in 10,000 are allowed through a filter, if it is to be rated as HEPA grade. Typically the paper passes fewer than 1 in 10,000. None of these is larger than 5 microns, unless there is a leak in the filter.
Media = The filter paper which traps particles from the air flowing through it. It is made of boro-silicate glass fibers and binder. It is not a particularly strong paper when new, and is extremely fragile after burn-off.
Binder = A substance used to bond the glass fibers together that gives some structural strength to the media. The binder is a normal part of HEPA filter manufacturing.
Separators = Components which hold the media pleats apart and channel the airflow. They are typically corrugated aluminum foil, but string, lines of glue, and other schemes have been used.
DOP = Dioctyl Phthalate - An oily liquid (plasticizer) used to produce aerosol droplets of .3 micron size ("hot DOP" for filter efficiency measurements) and 2 to 4 micron size ("cold DOP" to test filters for leaks)
Burn-Off = A high temperature process for removing the binder from the filter. It should be continued long enough to remove the smoke and odor from the oven. Manual cleaning of the oven is usually required afterwards.
Shedding = The filter behavior characterized by higher levels of particles downstream during changing temperature. Faster temperature changes result in larger particle counts. This is a typical characteristic of filters after the binder has been burned off of the media.
Pleat = The fold in the media at each face of the filter. The pleating gives the filter a large media surface area.
Packaging and Shipping
Packaging varies among filter manufacturers. Normally HEPA filters are packaged in internally strengthened cardboard boxes. The filters are packaged with the separators vertical - running from the top to the bottom of the package. The package should be clearly marked with a vertical arrow and a THIS SIDE UP label.
Typically, all the HEPA filters required for an oven will be banded together on a single pallet for shipment, with plywood sheets protecting the paper faces either in each carton or on the whole pallet.
CAUTION: When receiving a shipment of HEPA filters, make sure that they have been shipped with pleats oriented vertically. In horizontal shipment, normal road vibration and jarring may cause the filter media to sag. Any rough handling can cause subtle damage to the filter. This damage is quite difficult to see but will show up as leaks. Damage of this sort will typically make the filter unsuitable for oven use.
Handling and Storage
Minimize unnecessary handling. HEPA filters should be handled like very fragile glass. They should never be dropped or jarred. Any filter dropped, whether or not in the carton, should be re-examined for damage as described under Inspection. Filters should remain in their crates and shipping cartons until installation.
When handling a filter, it is recommended that the unit be tilted up on one corner, and picked up by the two adjacent corners (diagonal from each other).
Always maintain the filter in the proper vertical position, as marked on the container, during storage.
Unpacking
Remove the crate from around the carton(s) - as close to the oven as possible. Use extreme caution when removing the filter from its carton. The filter should not be dropped or jarred.
Be sure the area is large enough and clear of obstacles which may damage the filter. Carefully remove the sealing tape from the top of the carton.
CAUTION:
Attempting to remove the filter from the carton by grasping the filter frame can result in irreparable damage, when fingers puncture the delicate filter media.
Inspection
Use a strong lamp to examine the exposed areas of the filter to assure that no breaks, cracks or pinholes are evident. A less intense light, such as a flashlight, can be used in a darkened room.
HEPA Filter Replacement
HEPA filters should be replaced when they no longer perform the required function. Some of the more common reasons are:
Installation
Anyone installing HEPA filters must be aware of the high-efficiency performance required. Moreover, they should know that the filter pack within each frame is delicate, and must not be damaged during installation. Also, each filter must be installed so that unfiltered air will not leak past. The surface to which a filter is mounted should be true, clean, smooth, flat, free of weld splatter, and sufficiently rigid to fully compress the gasket (typically to about half its new or uncompressed height).
The following procedure is recommended.
Burn-Off of Binder
The burn-off process will take place in any piece of equipment where a new HEPA filter is used at temperatures above 150°C / 300°F. There will be smoke, possibly a pungent odor, and a residue on interior surfaces. This is a result of oxidation of the binder, and the evaporation/decomposition of any challenge agents. One of the media manufacturers says that most of the binder will leave the filter after running at a temperature of 260°C / 500°F for eight (8) to 48 (forty-eight) hours. After eight hours 4.2% of the total media weight is lost, and 4.8% after 48 hours. Approximately .1% will be lost after that. Check the oven for particles or the exhaust for smoke and odor to determine that the burn-off is finished.
When the filter media has the binder burned out, it becomes very fragile. After that, a filter may not stand up to normal handling, and especially shipping. Do not expect HEPA performance if HEPA filters are handled after binder burn-off.
Significant advantage in paper strength and shedding characteristics is obtained for some filters if some of the binder is left on the media (burn-off done below 220°C / 428°F, and the lower, the better). However, the burn-off should be done at or above the maximum process temperature. If the binder is burned off below 260°C / 500°F, it is wise to remember that additional smoke will be given off when an oven is heated over this maximum process temperature.
Select a location for this process where the smoke and odor generated will be ventilated with the least amount of interruption and inconvenience. Ideally this will be in the final location for the oven. However, it may be a receiving dock, some well ventilated space or even outside if the weather is acceptable. If this location is a very clean area, then special attention must be given to an exhaust hook-up that will capture the smoke and odor.
The following procedure is recommended:
Figure #1
Use enough fresh air or purge nitrogen to remove the smoke, while still being able to achieve and maintain the necessary temperature.
The completion of the burn-off period should be based on the particle level in the oven. Laminated media will take longer than the standard HEPA media to burn off to a particular cleanliness level, at the same temperature. Both types of media will burn off faster at higher temperature. Neither has a clearly defined end to the burn off process, and will continue to clean up during oven operation. The laminated media generally will clean up to a lower particle level than the standard media. Filters for below 260°C / 500°F: Normally clean up within 72 hours at 500°F. Filters for above 260°C / 500°F: Normally clean up within 24 hours at 750°F.
If it is necessary to move the equipment after the burn-off process (which is not recommended), considerable care should be used. The binder which gives strength to new filters is now gone and the media is very fragile. Any handling of either the filter alone or the equipment with the filter installed is strongly discouraged. The media may crack or tear (leak).
For best clean oven processing, it is recommended that the oven be thoroughly cleaned after the burn-off period and at regular intervals thereafter.
The filter hold-down nuts should be checked after burn-off and tightened again, if necessary. For best results, this step should also be repeated on a regular basis. Most oven gaskets are known to take a set, and thus require tightening after heating.
Testing
The filters are frequently checked for leakage after installation. DOP and similar challenge agents are not recommended for use in ovens, because of their behavior at elevated temperature.
Testing varies widely among different companies. However, it should be noted that efficiency testing of the recirculation filters is not required. It is generally sufficient that the filter be able to maintain the required cleanliness class of the oven. This would be done after the burn-off of the binder. One way to check the particle level, in an oven at elevated temperature, is to pull samples of the air out through a heat exchanger to a particle counter. Another is to determine a correlation between settling rate onto monitor wafers at ambient temperature. Then monitor wafers are used in the oven through the oven cycle. Contact the factory for further information.
We hope you will find this information useful. THANK YOU for contacting us and allowing us to be a service to you. Please contact us at 1-800-473-7373 if you have any questions.
Before you begin, we recommend using a certified analog thermocouple simulator/calibration source with less that +/-1°F noise. We have experienced signal stability problems with some micro-processor based thermocouple simulator/calibrators that induce an error during the calibration procedure. This error generally results in a non-linear shift in the controller's indicated temperature.
Note: When using a non ambient compensated calibrator or milli-volt source, the ambient temperature of the Protocol Controller must be subtracted from the input signal. Example: 250°F = 6.420mv and 75°F = 1.220mv, the correct input signal would equal 5.200mv. If the ambient temperature of the Protocol Controller is other than 75°F, use the correct milli-volt value.
Milli-volt Table
70° |
72° |
74° |
76° |
78° |
80° |
82° |
1.076mv |
1.134mv |
1.191mv |
1.248mv |
1.306mv |
1.363mv |
1.421mv |
Note: We recommend using shielded thermocouple lead wire to reduce the possibility of noise corruption.
NOTE: If the Display blinks and does not display HCAL, either key sequence is wrong or the controller calibration maybe newer style and proceed to the latest calibration procedure on page #5.
The calibration procedure is complete.
LATEST CALIBRATION PROCEDURE
The calibration procedure is complete.
Calibration Recovery
The Protocol control has a factory calibration recovery feature. This feature allows the operator to restore the Protocol to an operational condition should a calibration error occur. The Factory Calibration Recovery feature should only be used as a temporary fix until a proper calibration procedure utilizing a calibration source can be performed. Only a complete calibration will restore the Protocol to an optimum performance level.
For proper calibration instructions refer to the calibration section of this manual.
Instructions
The calibration recovery is now complete.
Diagnostics Mode
The diagnostics mode is provided to give certain relative information about Protocol. The following table gives an outline of the diagnostics mode.
Display |
Description |
DIAGNOSE |
Select Diagnostics mode. |
SSR |
Protocol SSR output level. |
EVENTS |
Events 1-3 follow |
E-1 |
Event 1 output |
E-2 |
Event 2 output |
E-3 |
Event 3 output |
SENS-T/C |
Control thermocouple display follows |
GOOD ### |
Control thermocouple test and input reading in degrees |
HL - T/C |
Hi-limit thermocouple display follows |
GOOD ### |
Hi-limit thermocouple test and input reading in degrees |
PWR |
% output |
RCVR SEN |
Recover factory calibration for control sensor |
RCVR HIL |
Recover factory calibration for high limit sensor |
Items that can be adjusted by the user include SSR (ON or OFF), Events E-1, E-2 and E-3(ON or OFF) and PWR. The SSR and PWR items can be used to test the solid state relay for proper operation. The SSR item allows the SSR to output 100% (ON) or 0% (OFF). The PWR item allows for adjustable output from 0% to 100%. to implement, adjust the PWR level with the +/- keys and turn on the heater relay.
RCVR SEN and RCVR HIL are used to restore the factory calibration should a calibration error occur.
We hope you will find this information useful. THANK YOU for contacting us and allowing us to be a service to you. Please contact us at 1-800-473-7373 if you have any questions.
The information that you are looking for is not readily available and requires us to search through our records. This includes requests for:
We would be happy to research the information requested. This is not a free service and will require a purchase order to perform the work. We will respond within three (3) to five (5) business days of receipt of a copy of your purchase order or a written acknowledgment of our rates (by fax or mail).
Most of the above items are typically included within the equipment’s original operating instruction manual. The operating instruction manual contains:
In addition, we have available for most of our standard controller’s a supplemental manual.
Replacement operating instruction manual are available through our Parts Department at 1-800-473-7373 Option #2. The cost is not based on the material content, but time required to research and assemble the replacement manual. On standard models the cost for a replacement manual will generally range from $200 to $400. On special or large engineering system equipment, a review of the equipment would be needed to determine the replacement manual cost.
We hope you will find this information useful. THANK YOU for contacting us and allowing us to be a service to you. Please contact us at 1-800-473-7373 if you have any questions.
Most of the items listed below are typically included within the equipment’s original operating instruction manual.
The operating instruction manual contains:
In addition, we have a supplemental controller manual (E-34) available for the DIGITRONIC controller.
Replacement operating instruction or supplemental manual(s) are available through our Parts Department at 1-800-473-7373 Option #2.
A Troubleshooting Guide For DIGITRONIC Controller has been included as follows.
PROBLEM or SYMPTOM |
PROBABLE CAUSE |
SUGGESTED CORRECTIVE ACTION |
Erratic temperature control |
|
The controller has a fixed proportion band (pb) of 5°F.
|
Setpoint drifts up & down |
Defective Potentiometer Defective Controller |
Disconnect the potentiometer wires from the terminals #P1 & P2, the setpoint should ramp to the maximum and should stabilize. |
Setpoint drifts up & down |
Defective Potentiometer Defective Controller |
Disconnect the potentiometer wires from the terminals #P1, P2 & P3.
If the setpoint drifts more than one (1) degree in either jumper position, the controller is defective. |
Modify setpoint potentiometer from |
|
Remove jumper from potentiometer terminal #3 to #2. Connect a new wire on terminal #3. Connect as follows:
If the setpoint goes down-scale when adjusted CW, reverse the P1 and P3 leads. |
Display reads "EEE", "000" or three dots |
Incorrect Potentiometer Connections
Broken Thermocouple |
|
Temperature runaway - heater will not turn "OFF" |
Shorted TRIAC Defective controller |
Disconnect the "G" lead from the terminal strip. If heater stays "ON", replace TRIAC. |
Controller will not gate TRIAC |
Defective optical isolator chip. |
Short T2 & G terminals. If Triac fires:
If Triac doesn't fire, Triac is defective. |
Controller will not gate TRIAC |
Defective chip switch |
Short T2 & G terminals. If Triac fires:
If Triac doesn't fire, Triac is defective. |
Test SCR gate signal output |
|
Disconnect either the (+) or (-) wire at the terminal strip and connect a VOM (set on 10vdc/higher scale) across the (+) & (-) terminals.
|
Test optical isolator module. |
|
The optical isolator chip is an obsolete part. If the SCR gate signal output is functioning OK, we recommend converting to SSR drive system. Use SSR kit P/N 203580. |
Test chip switch |
|
The controller has two chip switches, normally only one is used. If the oven is not equipped w/ a process timer you can swap K37 (alarm) w/ K44 (Triac). BEFORE REPLACING CHIP SWITCH, MAKE SURE THE TRIAC IS NOT SHORTED ACROSS THE GATE LEADS (white and red leads)!
|
Test proportional control signal for optional control motor M744D, M744J, M7984N |
|
The controller output range is from -10vdc to 10vdc (typically operating within -5vdc to 5vdc). The normal operating range of the control motor is 0vdc (full closed) to 2.5vdc (full open).
Some control motors are equipped with a trim potentiometer which allows you to shift the point at which the damper motor starts to drive open. For example if you want the damper to start to open prior to the process displayed temperature reaching the setpoint. You would adjust the trim potentiometer to operate in the negative end of the proportional range (-0.5vdc to 2.0vdc). |
We hope you will find this information useful. THANK YOU for contacting us and allowing us to be a service to you. Please contact us at 1-800-473-7373 if you have any questions.
Most of the items listed below are typically included within the equipment’s original operating instruction manual.
The operating instruction manual contains:
In addition, we have a supplemental controller manual (E-72) available for the Protocol controller and an Addendum explaining how to calibrate the controller.
Replacement operating instruction or supplemental manual(s) are available through our Parts Department at 1-800-473-7373 Option #2.
A Troubleshooting Guide For PROTOCOL Controller has been included as follows.
PROBLEM/SYMPTOM |
PROBABLE CAUSE |
SUGGESTED CORRECTIVE ACTION |
Erratic temperature control |
|
The controller typically has a proportion band (pb) of 5°F.
|
Temperature will not reach the Setpoint |
The heater is not turning ON
Defective SSR The Hi-limit relay does not click or pull in when pressing the heater on push-button |
|
Display reads |
The process temperature has exceeded the Hi-limit temperature setpoint. Controller Calibration |
Set the hi-limit to a higher temperature and press the RESET push-button. Check diagnostics mode for actual temperature readout of the Hi-limit (HL-T/C). If the reading is off by greater than 2-3 degrees or displays 500°C (932°F), calibrate the controller. |
Display reads |
The Control thermocouple is open |
|
Display reads |
The Hi-limit thermocouple is open |
|
Temperature runaway - heater will not turn "OFF" |
Shorted SSR Relay Defective controller |
Disconnect the one of the SSR leads (SSR terminal #3 or #4). If the heater stays "ON", Replace SSR. If heater turns "OFF", controller maybe defective |
The center of the chamber temperature is different from the control temperature displayed |
The hot air entering the chamber will be the hotter than center of the chamber. |
Change the CZO value in the Tune Mode to shift the controller’s displayed readout to the temperature in the center of the chamber. |
No digital display with the power LED ON |
The control power supply is defective |
Replace the Protocol controller. |
Test SSR gate signal output |
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Connect a VOM (set on 20vdc/higher scale) across the SSR Relay input terminals (SSR terminal #3 and #4)
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Keypad does not work or only some of the keys beep |
Defective Protocol |
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Hi-limit relay does not click or pull in when pressing the heater on push-button |
No power or voltage to the Protocol to energize the relay (ex. airflow switch is not closed). The Protocol hi-limit is not energizing relay even if the Heater Relay LED is on or faintly lite. |
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No Events are displayed in Profile |
Events not enabled |
The CODE*E* is located under Tune Mode. Using the same code as required for the Tune Mode, change the number of relays to the number of events being used (ex. Display indicates zero (0) relays used change the number to one (1) for Event One). |
Control or Hi-limit readout displays 500°C or 932°F |
Loss of calibration |
Perform calibration per Manual or Addendum. |
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WARNING: Maintenance on Electrical Equipment should be performed by qualified personnel, who are experienced in handling all facets of electrical systems. Failure to follow this warning can result in property damage, personal injury, or death.
There are several things that could cause the equipment to be slow to heat-up. The most common causes are:
CHECK LIST ITEMS
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Typically you want to run with the fresh-air and exhaust damper closed as much as possible, while trying to maintain a neutral, or slightly positive chamber pressure. Except in cases where your process gives off smoke or noxious fumes, in which case it would be necessary to either increase both of the damper settings (to increase the amount of air changes in the work space), or to adjust the dampers to run with a slightly negative pressure.
The best possible work space/chamber uniformity will be obtained if the work space/chamber is slightly positive.
The recommended method of measuring these pressures is by using a draft gauge. An alternate method is to run smoke (examples: cigarette, incense,or smoldering newspaper) along the door seal to detect positive or negative pressures.
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WARNING: Setup and maintenance of the equipment should be performed by qualified personnel, who are experienced in handling all facets of this type of combustion system. All combustion systems are capable of producing violent explosions or fires that may result in equipment damage, personal injury or possible death when improperly setup, operated, or maintained. If you do not understand any part of the information contained within this guide, contact the Despatch Service Products Division at 1-800-473-7373 to schedule service.
Typically the information that you are looking for is included within the equipment’s original operating instruction manual and vendor information guides.
The following are common checks that should be performed prior to proceeding:
The troubleshooting guide that follows is a general guide that covers a wide range of burner packages. In some cases the information listed in the probable cause section may not be applicable.
SYMPTOM |
PROBABLE CAUSE |
Burner flame relay malfunction: |
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Airflow switch malfunction: |
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Burner malfunction: |
Refer to the equipment’s original operating instruction manual, or the listed on the Nameplate mounted on the equipment (typically on the control compartment door, or the rear of the equipment).
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Control relay 1CR (manual start) malfunction: |
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Gas pressure switch malfunction: |
Refer to the equipment’s original operating instruction manual, or the listed on the Nameplate mounted on the equipment (typically on the control compartment door, or the rear of the equipment).
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Gas regulator malfunction: |
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Motor starter malfunction: |
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Purge cycle malfunction — will not complete: |
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Temperature controller malfunction: |
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There are several things that could cause improper Humidity Control. The Five most common causes are:
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There are several things that could cause improper Temperature Control or no cooling.
Control Panel
Chamber Interior
Lower Compressor Compartment (Rear Area)
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WARNING: VOLTAGE AND AMPERAGE CHECKS, OR ELECTRICAL CHANGES SHOULD BE PERFORMED BY A QUALIFIED ELECTRICIAN OR MAINTENANCE TECHNICIAN. WORK PERFORMED BY UNQUALIFIED PERSONNEL MAY RESULT IN EQUIPMENT DAMAGE, PERSONAL INJURY OR POSSIBLE DEATH.
The following information is typical guideline items to check whenever temperature uniformity problems occur.
Common Temperature Uniformity Variables
Equipment utilizing a modulating temperature control configuration are typically capable of achieving +/-2.0% temperature uniformity at a given operating temperature
(Example: +/-10°F @ 500°F). This assumes the equipment is in good working order.
Equipment utilizing a On-Off temperature control configuration are typically capable of achieving similar temperature uniformity at a given point in the on-off cycle. An on-off control system introduces a temperature oscillation (saw-tooth effect) that is inherent. The uniformity spread will oscillate, following the temperature oscillation, with overall temperature uniformity dependent upon the amount of control oscillation. On-off control systems can typically oscillate from 5°F to 30°F.
Temperature Uniformity Check List
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WARNING: Maintenance on Electrical Equipment should be performed by qualified personnel, who are experienced in handling all facets of electrical systems. Failure to follow this warning can result in property damage, personal injury, or death.
The airflow switch's function is to monitor the blower fans to prove they are in operation.
For example, to test the recirculation blower fan’s airflow switch:
To make adjustments, remove the aluminum hex cap on the top of the stem. To increase the setting, turn clockwise (CW) (adjustment screw down), to decrease the setting, turn counter-clockwise (CCW) (adjustment screw up). The position of the adjustment screw can be viewed through the slot in the stem. The top of the screw indicated the switch’s pressure setting.
Note: This procedure should be repeated for each airflow switch in the system.
Common causes of airflow switch malfunction:
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It has been our experience that best system controllability is obtained by placing the control sensor (element, T/C, RTD, Etc.) directly in front of the supply air discharge. In this configuration the control sensor is able to rapidly sense changes in the delivery air temperature. This control sensor configuration typically will produce the smallest over and under shoot during a ramp to the setpoint temperature, the smallest control loop oscillation during the soak at setpoint temperature and best temperature uniformity.
As the control sensor is moved out of the supply air discharge into the oven work chamber it’s sensitivity decreased due to a reduction of discharge air velocity, the entrainment air effect, part loading (disturbing air flow) and part radiation effect. This control sensor configuration typically will produce increased over and under shoot during a ramp to the setpoint temperature, increased control loop oscillation during soak at the setpoint temperature and increased oscillation and spread in a uniformity survey. Also the supply air heat temperature will increase and could exceed the equipment’s maximum design.
THEREFORE DESPATCH WILL NOT BE HELD LIABLE FOR DAMAGE TO EQUIPMENT RESULTING FROM THE MISUSE OR UNAUTHORIZED CHANGES MADE TO THE EQUIPMENT.
If your requirement is to monitor or record the work zone air temperature or part temperature, it is Despatch’s recommendation that you add a separate sensor(s) and the instrumentation needed to monitor or record the point(s) required without modifying the ovens current control sensor location.
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WARNING: IT IS THE CUSTOMER’S RESPONSIBILITY TO MEET ALL STATE AND LOCAL CODES, AND INSURANCE REQUIREMENTS. IMPROPER INSTALLATION OF THE EQUIPMENT COULD CAUSE A FIRE THAT MAY RESULT IN EQUIPMENT DAMAGE, PERSONAL INJURY OR POSSIBLE DEATH.
THE FOLLOWING INFORMATION IS A TYPICAL GUIDELINE ONLY!
We recommend you contact your local building inspection service or a qualified mechanical contractor for specific recommendations and/or requirements on your installation.
Equipment’s Maximum Operating Temperature |
Combustible Walls |
Non-Combustible Walls |
||
Ceiling |
Walls |
Ceiling |
Walls |
|
350°F to 650°F |
18" |
6" |
12" |
3" |
651°F to 1000°F |
24" |
12" |
18" |
6" |
1001°F to 1400°F |
30" |
18" |
24" |
12" |
Access clearance in front of motors shall be 32".
Access clearance in front of the control cabinet/compartment shall be in compliance with NEC 1993, ARTICLE 110-32. Some typically examples:
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WARNING: IT IS THE CUSTOMER’S RESPONSIBILITY TO MEET ALL STATE AND LOCAL CODES, AND INSURANCE REQUIREMENTS. IMPROPER INSTALLATION OF THE EXHAUST STACK COULD CAUSE AN EXPLOSION THAT MAY RESULT IN EQUIPMENT DAMAGE, PERSONAL INJURY OR POSSIBLE DEATH.
We recommend you contact your local building inspection service or a qualified mechanical contractor for specific recommendations and/or requirements on your system.
Despatch Industries is not a mechanical contractor.
THE FOLLOWING INFORMATION IS A TYPICAL GUIDELINES ONLY!
Note: Volume of Air in Cubic Feet per Minute (CFM) is equal to the Air Velocity in Feet per Minute (FPM) times the area (Ft2)
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Typical exhaust duct installation for passing through combustible roofs when the stack temperature are below 650
Figure #1 & Figure #2
TABLE #1 |
|
Stack Diameter |
Clearance "A" |
10" or less |
8" |
over 10" |
12" |
Typical exhaust duct installation for passing through combustible roofs when the stack temperature are 650 F or above.
Figure #3 & Figure #4
(650°F to 1050°F) & (Over 1050°F)
TABLE #2 |
|
|
Stack Diameter |
Clearance "A" |
Clearance "B" |
10" or less |
4" |
9" |
over 10" |
6" |
12" |
Commoned Exhaust Stacks
Separate ovens should not be commoned together in one exhaust stack because a differential pressure in the wrong direction is possible due to room pressure when running only one oven.
The exhaust from running oven(s) can fill up inside non-running oven(s) instead of venting outside via the exhaust stack.
This method should not be used!
One common exhaust blower fan system can be used, but it must be proven to be operating before any of the ovens are operated. This also presents a problem to balance the exhaust flow from each oven. It is necessary to insure that each oven is exhausting the correct airflow.
The best way is to provide individual stacks for each oven with their own roof opening or running individual stacks through one opening in the roof.
Wall Losses and Energy Consumption
Calculating Wall Losses or Energy Consumption is extremely difficult to estimate for a number reasons. The actual energy usage can vary from model to model. This is also true for identical equipment depending on the following conditions:
CALCULATING FUEL CONSUMPTION AND WALL LOSSES
The best way to determine the wall losses or energy consumption is to operate the equipment and obtain the actual values.
ON/OFF Control System
With the equipment at setpoint for a minimum of sixty (60) minutes:
Example: 68 Kw electric oven operating at 350°F, the HEAT ON pilot light was on for eight (8) minutes and off for twelve (12) minute.
Modulating Control System (Gas Fired)
See Note #2: Modulating Control System (SCR Fired - Silicon Controlled Rectifier)
See Note #3: Modulating Control System (SSR Drive - Solid State Relay)
With the equipment at setpoint for a minimum of sixty (60) minutes:
Example: 136 Kw electric oven operating at 550°F, the controller output averaging 60% at setpoint.
Wall Losses Calculations:
To calculation wall losses, use the same procedures/example listed above, while operating the equipment empty at the desired setpoint temperature with the fresh-air and exhaust dampers closed fully.
Note #1: When calculating the usage during the ramp from ambient to the process temperature you should generally figured it at 100% of the rated heater kilowatt hours or burner BTU's per hour.
Example: 1,000,000 BTU's gas fired oven takes 30 minutes to ramp from 70°F to 500°F.
Note #2: Because of the non-linearity of gas valves, you can not accurately calculate fuel consumption of a modulating gas fired system without configuring them to operate ON/OFF. The simplest and most accurate method in this case is to connect a gas flow meter in-line to monitor fuel flow rates.
Note #3: Because of the non-linearity of some SCR firing systems, you can not accurately calculate fuel consumption of a modulating SCR fired electric system without configuring them to operate ON/OFF.
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Painting
Normally an unpainted mild steel interior surface will not rust if the equipment is used continually above 220°F. The humidity level will be very low as the moisture will be boiled off during the process. If the equipment sets idle for long periods of time, moisture can condensate on these surfaces and start rusting.
There is high temperature paint available to cover the interior surfaces of equipment able to with stand operating temperature of up to 750°F. The interior surfaces must be free of rust or other debris prior to painting or re-caulking. The rust will bleed through the paint, if not removed prior to painting. This paint remains soft and does not dry hard. The paint will smear and rub off when it is touched.
This paint comes in gallon can P/N 008574.
Caulking
We use several types of caulking for the panel joints:
Insulation Void Filler
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WARNING: Setup and maintenance of the equipment should be performed by qualified personnel, who are experienced in handling all facets of this type of combustion system. All combustion systems are capable of producing violent explosions or fires that may result in equipment damage, personal injury or possible death when improperly setup, operated, or maintained.
There are several things that could cause the equipment to be slow to heat-up. The most common causes are:
CHECK LIST ITEMS
On equipment operating up to 650°F, the chamber pressure should be neutral or slightly positive with respect to the room or work space the equipment is located. (slightly positive is preferred) On high temperature units (operating above 650°F) running pressurized can cause warping problems, it is generally recommended that you operate as close to a neutral condition as possible. The chamber pressure can be varied by making adjustments to either the fresh air or, the exhaust dampers.
An extreme negative condition would be with the exhaust damper full open and the fresh air damper full closed.
An extreme pressure or positive condition would be with the exhaust damper full closed and the fresh air damper full open.
We hope you will find this information useful. THANK YOU for contacting us and allowing us to be a service to you. Please contact us at 1-800-473-7373 if you have any questions.