Jackson Tempstar TGP, Gas Heated Door-Type Dishmachines Tempstar TGP User Manual

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DUAL TEMPERATURE, GAS HEATED

DOOR-TYPE DISHMACHINES

TECHNICAL MANUAL

INSTALLATION MANUAL FOR EXPORT UNITS

SERVICE MANUAL FOR DOMESTIC UNITS

FOR JACKSON MODEL:

TEMPSTAR TGP

June 24, 2004

P/N 7610-001-98-99 (Revision C)

An Company

Jackson MSC, Inc.

P.O. BOX 1060

HWY. 25E

BARBOURVILLE, KY. 40906

FAX (606) 523-9196

PHONE (606) 523-9795

www.jacksonmsc.com

TABLE OF CONTENTS

GENERAL

PAGE

Specifications .............................................................................................

1

INSTALLATION

 

Unpacking...................................................................................................

2

Plumbing Connections................................................................................

2

Electrical Connections................................................................................

2

Gas Connection..........................................................................................

3

OPERATING INSTRUCTIONS

 

Preparation..................................................................................................

4

Power Up....................................................................................................

4

Initial Fill......................................................................................................

4

Preparing the Dishes..................................................................................

4

Daily Machine Preparation..........................................................................

4

Washing a Rack of Ware............................................................................

4

Shut Down and Cleaning............................................................................

4

OVERVIEW OF OPERATION...................................................................................

5

THERMOSTAT ADJUSTMENT PROCEDURE........................................................

7

AUTO-CALIBRATION PROCEDURE.......................................................................

8

ELECTRONIC CONTROL BOARD (ECB)...............................................................

9

TESTING THERMISTORS........................................................................................

10

CONTROL BOARD LED LIGHT INDICATIONS......................................................

11

TROUBLESHOOTING..............................................................................................

12

DIMENSIONS............................................................................................................

19

TABLE DIMENSIONS...............................................................................................

20

PHOTOGRAPHS

 

Main Assembly............................................................................................

21

Control Box Assembly-Front View..............................................................

22

Control Box Assembly-Top View.................................................................

23

Hood Assembly...........................................................................................

24

Cantilever Arm Assembly............................................................................

25

Tub Assembly..............................................................................................

26

Back of Tub, & Drain Assembly..................................................................

27

Lower Assembly (Right Side).....................................................................

28

Incoming Plumbing Assembly.....................................................................

29

Gas Pack Assembly....................................................................................

31

Upper Wash, & Rinse Arm Assembly.........................................................

32

Lower Wash, & Rinse Arm Assembly.........................................................

33

Steam Coil Assembly..................................................................................

34

Rinse Tank Assembly..................................................................................

36

Electronic Control Drawer Components......................................................

37

METRIC CONVERSION...........................................................................................

38

SCHEMATICS

 

208/240 Volt Schematic..............................................................................

39

i

SPECIFICATIONS OF THE TEMPSTAR TGP

PERFORMANCE/CAPABILITIES

 

OPERATING CAPACITY (RACKS/HOUR)

 

RACKS PER HOUR

57

DISHES PER HOUR

1425

GLASSES PER HOUR

1425

OPERATING CYCLE (SECONDS)

 

WASH TIME

45

RINSE TIME

11

DWELL TIME

2

TOTAL CYCLE TIME

60

TANK CAPACITY (GALLONS)

 

WASH TANK (MINIMUM)

8.0

BOOSTER TANK

3.0

TANK CAPACITY (LITERS)

 

WASH TANK (MINIMUM)

30.28

BOOSTER TANK

11.36

WASH PUMP CAPACITY

 

GALLONS PER MINUTE

150

LITERS PER MINUTE

567.81

TEMPERATURES

 

WASH ---°F (MINIMUM)

150

WASH ---°C (MINIMUM)

65.56

RINSE ---°F

180

RINSE ---°C

82.22

ELECTRICAL REQUIREMENTS

 

WASH PUMP MOTOR HP

3/4

CIRCULATOR PUMP MOTOR HP

1/12

VOLTS

PHASE

AMPS

208 - 240

1

6.7

WATER REQUIREMENTS

 

INLET TEMPERATURE

 

70 -140°F

INLET TEMPERATURE

 

21.11-60°C

GALLONS PER HOUR

 

52.0

LITERS PER HOUR

 

196.84

WATER LINE SIZE I.P.S. (Minimum)

3/4”

WATER LINE SIZE I.P.S. (Minimum)

1.9 CM

DRAIN LINE SIZE I.P.S. (Minimum)

1-1/2”

DRAIN LINE SIZE I.P.S. (Minimum)

3.81 CM

FLOW PRESSURE P.S.I. (Optimum)

20

GAS REQUIREMENTS

 

 

BTU INPUT RATE

 

55,000

INLET LINE PRESSURE (TOWN GAS)

4-6” wci

MANIFOLD PRESSURE

(MINIMUM)

.25 wci

 

(MAXIMUM)

2.3 wci

FRAME DIMENSIONS

 

 

WIDTH

 

25 3/4”

WIDTH

 

65.4 CM

DEPTH

 

25 1/4”

DEPTH

 

64.14 CM

HEIGHT

 

56 3/4”

HEIGHT

 

144.15 CM

STANDARD TABLE HEIGHT

34”

STANDARD TABLE HEIGHT

86.36 CM

MAXIMUM INSIDE CLEARANCE

17 1/4”

MAXIMUM INSIDE CLEARANCE

43.82 CM

RACKS

 

 

DISH 20” X 20” (50.8 CM X 50.8 CM)

OPTIONAL

GLASS & SILVER 20” X 20” (50.8 CM X 50.8 CM)

OPTIONAL

1

2
WATER SUPPLY CONNECTION: Ensure that you have read the section entitled “PLUMBING THE DISHMACHINE” above before proceeding. Install the water supply line (3/4” pipe size minimum) to the dishmachine line strainer using copper pipe. It is recommended that a water shut-off valve be installed in the water line between the main supply and the machine to allow access for service. The water supply line is to be capable of 20 PSI “flow” pressure at the recommended temperature indicated on the data plate.
VOLTAGE CHECK: Ensure that the power switch is in the OFF position and apply power to the dishmachine. Check the incoming power at the terminal block and ensure it corresponds to the voltage listed on the data plate. If not, contact a qualified service agency to examine the problem. Do not run the dishmachine if the voltage is too high or too low. Shut off the service breaker and mark it as being for the dishmachine. Advise all proper personnel of any problems and of the location of the service breaker. Replace the control box cover and tighten down the screws.
It is recommended that “DE-OX” or another similar anti-oxidation agent be used on all power connections.
To install the incoming power lines, open the control box. This will require taking a phillips head screwdriver and removing the one(1) screw on the front cover of the control box. Install 3/4” conduit into the pre-punched holes in the back of the control box. Route power wires and connect to power block and grounding lug. Install the service wires (L1 &L2) to the appropriate terminals as they are marked on the terminal block. Install the grounding wire into the lug provided. Tighten the connections and perform the “pull test”. The tightened wires should remain in place after giving the wires
CONNECTING THE DRAIN LINE: The drain for the Tempstar- a moderate pull to see if they will come loose. TGP is a gravity discharge drain. All piping from the 1 1/2 ” FNPT
connection on the waste accumulator must be pitched (1/4” per foot) (2.083 cm per meter) to the floor or sink drain. All piping from the machine to the drain must be a minimum 1 1/2” I.P.S. and shall not be reduced. There must also be an air gap between the machine drain line and the floor sink or drain. If a grease trap is required by code, it should have a flow capacity of 5 gallons (18.93 liters) per minute.
PLUMBING THE DISHMACHINE: All plumbing connections must comply with all applicable local, state, and national plumbing codes. The plumber is responsible for ensuring that the incoming water line is thoroughly flushed prior to connecting it to any component of the dishmachine. It is necessary to remove all foreign debris from the water line that may potentially get trapped in the valves or cause an obstruction. Any valves that are fouled as a result of foreign matter left in the water line, and any expenses resulting from this fouling, are not the responsibility of the manufacturer.
Disconnect electrical power supply and place a tag at the disconnect switch to indicate that you are working on the circuit.
The dishmachine data plate is located on the right side and to the front of the machine. Refer to the data plate for machine operating requirements, machine voltage, total amperage load and serial number.
LEVEL THE DISHMACHINE: The dishmachine is designed to operate while being level. This is important to prevent any damage to the machine during operation and to ensure the best results when washing ware. The unit comes with adjustable bullet feet, which can be turned using a pair of channel locks or by hand if the unit can be raised safely. Ensure that the unit is level from side to side and from front to back before making any connections.
ELECTRICAL POWER CONNECTION: Electrical and grounding connections must comply with the applicable portions of the National Electrical Code ANSI/NFPA 70 (latest edition) and/or other electrical codes.
PLUMBING CHECK: Slowly turn on the water supply to the UNPACKING THE DISHMACHINE: Once the machine has been machine after the incoming fill line and the drain line have been removed from the container, ensure that there are no missing installed. Check for any leaks and repair as required. All leaks parts from the machine. This may not be obvious at first. If it is dismust be repaired prior to placing the machine in operation. covered that an item is missing, contact Jackson immediately to
have the missing item shipped to you.
In areas where the water pressure fluctuates or is greater than the recommended pressure, it is suggested that a water pressure regulator be installed.
Do not confuse static pressure with flow pressure. Static pressure is the line pressure in a “no flow” condition (all valves and services are closed). Flow pressure is the pressure in the fill line when the fill valve is opened during the cycle.
It is also recommended that a shock absorber (not supplied with the Tempstar-TGP model) be installed in the incoming water line. This prevents line hammer (hydraulic shock), induced by the solenoid valve as it operates, from causing damage to the equipment.
VISUAL INSPECTION: Before installing the unit, check the container and machine for damage. A damaged container is an indicator that there may be some damage to the machine. If there is damage to both the container and machine, do not throw away the container. The dishmachine has been inspected and packed at the factory and is expected to arrive to you in new, undamaged condition. However, rough handling by carriers or others may result in there being damage to the unit while in transit. If such a situation occurs, do not return the unit to Jackson; instead, contact the carrier and ask them to send a representative to the site to inspect the damage to the unit and to complete an inspection report. You must contact the carrier within 48 hours of receiving the machine. Also, contact the dealer through which you purchased the unit.
INSTALLATION INSTRUCTIONS

GAS CONNECTION

It is very important that the type and inlet pressure of the gas used corresponds to the machine data plate. This machine is equipped with a 1/2” female line for connection of gas. The gas line used should be of the type approved for use with natural gas or propane, depending on the gas selected to be used in this machine. The gas line should be sized to carry the maximum flow of 55,000 BTUs. Too small of a gas line will result in poor performance. A manual gas shut-off valve must be installed in the gas line, located within an accessible area of the machine. The gas line should be kept as short as possible and installed in a way to protect it from damage.

When making pipe connections, use an AGA approved pipe dope, being careful not to use excessive amounts as to foul the gas valve or clog the gas line. When tightening the gas line always support the gas valve to avoid damage to the gas train.

When making the connection to the booster unit, take care to start the gas line fitting by hand and tighten by hand to avoid cross threading. Tighten fitting with a wrench, taking care not to damage any internal components of the unit.

After making a final connection of gas, with power to the unit turned off, check all gas line fittings for leaks, using a liquid test solution.

WARNING

ENSURE THAT THERE IS NO ELECTRICAL POWER APPLIED TO THE MACHINE WHEN MAKING GAS CONNECTION.

CHECK ALL GAS CONNECTIONS FOR LEAKS PRIOR TO APPLYING POWER.

THE GASES USED FOR COMBUSTION IN THIS DISH MACHINE ARE HIGHLY FLAMMABLE.

DO NOT SMOKE AROUND THIS MACHINE.

ENSURE THAT THE AREA WHERE THIS MACHINE IS TO BE INSTALLED IS WELL-VENTILATED TO PREVENT THE BUILD-UP OF COMBUSTIBLE GASES.

ENSURE THAT ALL LOCAL HEALTH, FIRE, AND BUILDING CODES ARE BEING ADHERED TO WHEN INSTALLING THIS MACHINE. VERIFY WITH LOCAL OFFICIALS IF THERE ARE ANY QUESTIONS.

INSTALL A SHUT-OFF VALVE AT THE GAS SOURCE AND SUPPLY THE MACHINE USING A 1/2” LINE. CONNECT TO THE 1/2” NPT FITTING ON THE MACHINE.

3

OPERATION INSTRUCTIONS

PREPARATION: Before proceeding with the start-up of the unit, verify the following:

1.The pump intake, and wash tank strainers are in place and is clean.

2.The drain stopper is installed.

3.That the wash and rinse arms are screwed securely into place and that their endcaps are tight. The wash and rinse arms should rotate freely.

POWER UP: To energize the unit, turn on the power at the service breaker. The voltage should have been previously verified as being correct. If not, the voltage will have to be verified.

FILLING THE WASH TUB:Ensure that the delime switch is in the NORMAL position, and place the power switch into the ON position. The Tempstar-TGP should fill automatically and shut off when the appropriate level is reached (just below the wash tank strainer). Verify that the drain stopper is preventing the wash tub water from pouring out excessively. There will probably be some slight leakage from the drain hole. Verify that there are no other leaks on the unit before proceeding any further. The wash tub must be completely filled before operating the wash pump to prevent damage to the component. Once the wash tub is filled, the unit is ready for operation.

The water level was set at the factory. If the water level is not at the level noted above, it will require adjustment. Check to ensure that the recommended water pressure is being supplied to the machine (20 PSI). If the water pressure is correct then the fill valve will need adjustment. Use the following steps to adjust the cam. Turn power off at the machine circuit breaker. Open the control box cover. Locate the timer fill valve cam (Cam 4 from the timer motor). Locate the spanner wrench taped to the electrical panel. The spanner wrench is used to adjust the cam.

WARE PREPARATION: Proper preparation of ware will help ensure good results and less re-washes. If not done properly, ware may not come out clean and the efficiency of the dishmachine will be reduced. It is important to remember that a dishmachine is not a garbage disposal and that simply throwing unscraped dishes into the machine simply defeats the purpose altogether of washing the ware. Scraps should be removed from ware prior to being loaded into a rack.

Pre-rinsing and pre-soaking are recomended, especially for silverware and casserole dishes. Place cups and glasses upside down in racks so that they do not hold water during the cycle. The dishmachine is meant not only to clean, but to sanitize as well, to destroy all of the bacteria that could be harmful to human beings. In order to do this, ware must be properly prepared prior to being placed in the machine.

DAILY MACHINE PREPARATION: Refer to the section entitled “PREPARATION” at the top of this page and follow the instructions there. Afterwards, check that all of the chemical levels are correct and/or that there is plenty of detergent available for the expected workload.

WARM-UP CYCLES: For a typical daily start-up, it is recommended to run the machine through 3 cycles to ensure that all of the cold water is out of the system and to verify that the unit is operating correctly. To cycle the machine, ensure that the power is on and that the tub has filled to the correct level. Lift the doors and the cycle light will illuminate. When the light goes out, close the doors, the unit will start, run through the cycle, and shut off automatically. Repeat this two more times. The unit should now be ready to proceed with the washing of ware.

WASHING A RACK OF WARE: To wash a rack, open the doors completely (being careful for hot water that may drip from the doors) and slide the rack into the unit. Close the doors and the unit will start automatically. Once the cycle is completed, open the door (again watching for the dripping hot water) and remove the rack of clean ware. Replace with a rack of soiled ware and close the doors. The process will then repeat itself.

OPERATIONAL INSPECTION: Based upon usage, the wash tank strainer may become clogged with soil and debris as the workday progresses. Operators should regularly inspect the wash tank strainer to ensure it has not become clogged. If the strainer does, it will reduce the washing capability of the machine. Instruct operators to clean out the wash tank strainer at regular intervals or as required by work load.

SHUTDOWN AND CLEANING: At the end of the workday, close the doors. When the unit completes the cycle, turn the power switch to the OFF position and open the doors. Manually remove the drain stopper from the tub and allow the tub to drain (NOTE: the wash tank water will be hot so caution is advised). Once the wash tub is drained, remove the wash tank strainer and the pump suction strainer. Remove soil and debris from the strainer and set to the side. Unscrew the wash and rinse arms from their manifolds. Remove the endcaps and flush the arms with water. Use a brush to clean out the inside of the arms. If the nozzles appear to be clogged, use a toothpick to remove the obstruction. Wipe the inside of the unit out, removing all soil and scraps. Reassemble the wash and rinse arms and replace them in the unit. The arms only need to be hand tight, do not use tools to tighten them down. Reinstall the strainers and close the doors.

4

OVERVIEW OF OPERATION

PRESSURE

GAUGE

REGULATOR

RINSE ARM

CHECK VALVE

WASH TANK

WATER LEVEL

PROBE WL

THERMOSTAT

WASH TANK

COILS T

WASH TEMP 150-165 °F (65.56 - 73.89 °C)

RECIRCULATING

PUMP

VACUUM BREAKER

FILL / RINSE SOLENOID

TRINSE TEMP >180 °F (82.22 °C)

CHECK VALVE

BOOSTER

TANK

ECO

T-MID

HEAT

EXCHANGER

BURNER

ASSEMBLY

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MODULATING

COMBINATION GAS

 

VALVE

 

CUTOFF VALVE

 

 

 

 

 

 

 

 

 

 

The Tempstar TGP heating system is designed to heat and maintain the wash tank water temperature at a minimum of 150 °F (65.56 °C) as well as providing a constant 180 °F (82.22 °C) rinse water temperature. Incoming water is supplied at a pressure of 20psi and between 70-140 °F (21.11 - 60 °C). Incoming gas pressure should be between 4.0-6.0 WCI for town gas. The sequence of operation is as follows (please refer to the above diagram):

When the power is turned on at the ON/OFF switch the water level control board will sense a low water level in the wash tank and the unit will begin to fill. This occurs as the rinse solenoid valve opens, allowing connected water to fill the booster tank, heat exchanger and the rest of recirculating system, once the booster tank is full, water will fill the wash tank until the water level control system is satisfied. Simultaneously with the fill, the rinse recirculating pump and the gas burner assembly is energized, to begin heat up of the unit. A transformer in the main control box supplies +12vdc to the electronics control drawer location in the lower section of the unit. The electronics control board (ECB) is the brain of the system. The ECB receives various inputs and determines the amount of heating required.

When energized the ECB receives input from the T-mid thermistor indicating a low water temperature in the recirculating system. The ECB will power the ignition relay on the board, which in turn provides +12vdc to the direct spark ignition board (DSI). The DSI sends +12vdc to the combination gas cutoff valve to open it. This will supply gas to the burner assembly. The DSI begins sparking the igniter probe, and monitors the flames presence. If the flame is not sensed during the ignition attempt, then the DSI will lockout until the software resets the DSI approximately 60 seconds later.

5

OVERVIEW OF OPERATION (CONTINUED)

The operator may turn the power off at the ON/OFF switch for approximately 5 seconds, and then back on. This will also reset the ECB and the DSI. If flame is lost during normal burn, the DSI will attempt a reignition.

The ECB monitors the 12vdc signal from the DSI to the combination gas cutoff valve. The software in the ECB also reads the temperature at the middle of the heat exchanger with the T-mid thermistor. After the 5.5 second ignition time, the software will increase gas flow to the burner to minimum burn by increasing voltage to the modulating valve (MV). If the heat exchanger temperature is far away from the stabilization temperature, the software will increase gas flow to maximum burn.

Once the heat exchanger temperature nears the stabilization temperature the gas flow is slowly reduced until the minimum burn is attained. The software will keep the unit in minimum burn until the heat exchanger temperature exceeds stabilization temperature when the gas will be shut off. Over many minutes, the software will turn the burner off and on repeatedly until all the water in the system reaches the stabilization temperature. At this point the software will only turn the burner on every 1-2 minutes to maintain the stabilization temperature. Now the unit is ready for operation.

As the dishwasher pulls water from the tank, the water is replaced with cooler water. The need to heat the new water is sensed by the software and the burner is turned on. The software will modulate the gas flow between minimum and maximum gas flow attempting to recover the stabilization temperature and always keeping the tank temperature above the required temperature.

The stabilization temperature may be adjusted by means of a potentiometer located on the ECB. This is referred to as the T- set. (normally 4.25vdc)

The recirculating pump draws water from the rinse booster tank and circulates it through the wash tank coils where it will heat the water residing in the wash tank. The water then returns to the heat exchanger where it is reheated. This hot water then flows back to the rinse booster tank and repeats the cycle.

The thermostat,(in conjunction with the wash temp relay) is used during idle times to prevent wash tank temperature from exceeding 170° F (76.67°C), during normal operation the wash tank will self regulate between 150-165° F (65.56-73.89 °C). However, when idle, the temperature in the wash tank will slowly rise towards booster tank temperature until the temperature reaches 170° F (76.67°C). The wash tank thermostat will cycle the heat exchanger & recirculating pump off. When the wash tank temperature lowers, the heat exchanger and recirculating pump will energize. This will continue during all idle time. At any time that the unit is placed into operation, the wash

temp relay will energize and immediately power the heat exchanger and the recirculating pump, regardless of the thermostats position.

Excessive high temperatures in the system are avoided by the following: 1. high temperature limit control by input from T-mid thermistor, 2. energy cutoff temperature lockout (ECO) by means of a bi-metallic switch independent of the microprocessor which will break voltage to the combination gas cutoff valve if temperature in the system exceeds 210 F (98.89°C).

Excessive high pressures that potentially could be created in the system are vented directly to atmosphere by means of the rinse booster tank and rinse arms.

6

THERMOSTAT ADJUSTMENT PROCEDURE

1)Start up unit

2)Allow to fill, and start warm-up

3)Turn thermostat trim screw Counter Clockwise (CCW) 2 full revolutions

4)Allow wash temperature to reach 170# F on Wash Temperature Gauge

5)Turn thermostat trim screw Clockwise (CW) until flashing Green LED on control board turns off. (The recirculating pump will also turn off).

6)To ensure that the trim screw has not been turned too far CW, turn CCW very slowly until Green LED turns on and once again turn CW very slowly until Green LED goes out.

7)Start normal operation and monitor wash tank temperature.

8)If readjustment is needed repeat steps 5 - 7 until wash tank temperature maintains at 170#F (76.67°C),during idle time.

7

AUTO-CALIBRATION PROCEDURE

Model: TEMPSTAR GP, & TEMPSTAR TGP

This procedure must be completed every time you replace either a control board or a modulating valve.

AUTO - CALIBRATION

1.Turn the unit OFF at the main power switch and let stand for one minute.

2.Remove the lower front panel and set aside.

3.Remove the cover of the rectangular control box.

4.Locate the control board (see figure 1).

5.Locate and remove the jumper labeled ACAL (see figure 1) from the control board. Be careful to remove metal jumper not just the plastic insulator. Make a note of the exact position the jumper was located. Set jumper aside for later reinstallation.

6.With your multi-meter set on DC volts, attach to the molex plug going to the modulating valve.

NOTE: Do not disconnect molex plug. Insert probes in the rear of one side so the contact is made with the metal pins inside of the plug. (see figure 2).

7.Turn dishmachine ON. Burner will ignite and run through a series of steps. Watch the readings of your multi-meter. They will run approximately 11.9 VDC (23 VDC for the TGP) at the highest flame, step down to about 6.0 VDC (12 VDC for the TGP) and then step down again slightly to 5.7 to 5.8 VDC (11.4 to 11.6 - VDC for the TGP) before shutting the burner off. This whole process takes about 1 - 2 Minutes.

8.Once the burner goes out, turn dishmachine OFF.

9.Wait one minute.

10.Replace jumper on control board in the exact same place it came off.

11.Turn the dishmachine back ON.

Figure 1

Figure 2

 

 

8

ELECTRONICS CONTROL BOARD (ECB)

Testing and Setting the Set Point Temperature

The Control Board regulates the temperature of the water in the heat exchanger system. This water is also used as the rinse water for the rinse cycle of the dishwasher. It does this by regulating the flame of the burner by increasing or decreasing the voltage to the modulating valve. The modulating valve, in turn, increases or decreases the gas pressure going to the burner manifold depending on the voltage it is getting from the control board. From time to time it may be necessary to check or adjust the setting of this water temperature. To test the setting or to reset the temperature of the rinse water, make sure the unit is on and the green LED on the board is flashing steadily. Insert the NEGATIVE (Black/Common) probe of a multi-meter set on DC volts in the BLACK test point (see above). Insert the POSITIVE (Red) probe of the multi-meter in the BLUE test point. The reading will indicate the set point temperature. The factory setting is 4.25 VDC which corresponds to 198#F (92#C). Adjustments to the set point are made on the BLUE POTENTIOMETER directly below the BLUE test point. With a very small slotted screwdriver rotate the trim screw on the potentiometer clockwise (CW) to increase the voltage (and Temperature) and counterclockwise to decrease.

9

TESTING THE THERMISTORS

There are two thermistors that are used in controlling the temperature of the water in the heat exchanger system. The T- in that samples the temperature of the water going into the heat exchanger and the T-Mid that samples the temperature halfway through the heat exchanger. The Control Board constantly monitors the temperature at the T-Mid Thermistor and adjusts the burner pressure by way of the Modulating Valve according to how far away that temperature is away from the set point temperature.

Thermistors are devices that change their resistance value with changes in temperature. By running a constant voltage through the thermistor, one can read the change of voltage caused by the change of resistance thus determining the temperature of the thermistor. There are test points on the control board (see above) that can be read with a multi-meter on the Direct Current Volt (DCV) scale for each thermistor.

To test the temperature at the T-in Thermistor

There is a BLACK test point along the top edge of the control board on the right side of center. This is where the NEGATIVE (Common/Black) probe of a multi-meter is inserted. There is an ORANGE test point along the top edge of the control board on the left side of center. This is where the POSITIVE (Red) probe of a multi-meter is inserted. A DC voltage reading is then taken. Find

the voltage on the chart below and find the corresponding temperature.

To test the temperature at the T-Mid Thermistor

Using the same BLACK test point with the NEGATIVE probe of the multi-meters in testing the T-in thermistor above, also find the YELLOW test point on the left side of the board just under the large plug (see above). Insert the positive probe of the multi-meter and read DC Volts. Since the two thermistors have the same values, the same chart is used.

Gas Pack Thermister Conversion

 

4

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3.5

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

DC

2.5

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Voltage

2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1.5

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0.5

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

50(10)

.6)

.1)

.7)

.2)

.8)

.3)

.9)

.4)

140(60)

.6)

.1)

.7)

.2)

.8)

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.9)

 

60(15

70(21

80(26

90(32

100(37

110(43

120(48

130(54

150(65

160(71

170(76

180(82

190(87

200(93

210(98

 

 

 

 

 

 

 

 

Temperature °F (°C)

 

 

 

 

 

 

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CONTROL BOARD LED LIGHT INDICATIONS

The Electronic Control Board (ECB) has two LED light indicators that can be seen at its upper left hand corner. The following conditions for each light may be seen during operation of the unit.

1)Green LED is off.

A)Dishmachine is turned off, therefore no power to ECB.

B)Wash thermostat has cycled off, therefore breaking power to 12 volt transformer in the main control box. This will also disrupt power to the ECB.

C)ECB may have never recieved an AUTO CALIBRATION.

D)ECB may be damaged due to high voltage.

E)Control chip in ECB may be misaligned, not fully inserted, or damaged.

2)Green LED is a illuminated and steady.

A)ECB has been damaged in some form.

3)Green LED is illuminated and flashing.

A)This is the normal operating condition.(whether the LED flashes rapidly, or at a slower rate).

4)Red LED is off.

A)This is the normal operating condition.

5)Red LED is illuminated and steady, or flashing.

A)This is an indication of a malfunction of the T-MID Thermistor. Thermister may be unplugged, grounded, have frayed wiring, or other damage.

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