Finish Thompson LS-55IIE - Manual (Page 26)

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Advanced Troubleshooting Tips: LS15IIE I LS55IIE
Warning: Qualified electrical personnel must perform all electrical tests/work. There is a potential for
sparks when the electrical control box is open. The unit must be removed to a location outside the hazardous
area before any electrical work can be done on live circuits.
PROBLEM: Only green light comes on / still
1. With the on/off switch in the ON position (pulled out), opening the solenoid valve (sol-1) controls the water
flow. If 240 V.A.C. is present at the solenoid valve and the water is still not flowing, the solenoid valve is
defective and should be cleaned or replaced. If voltage is not present, check fuses FUI and FU2. If the fuses are
good, verify power from the power supply. There should be 24 V.D.C. between wires #7 (pos.) and #11 (neg.).
If there is not, then replace the power supply. If the power supply checks out all right and the solenoid valve still
does not power up, timer 2 (TIM-2) is probably defective and should be replaced.
2. Verify that the cooling water is properly supplied to the condenser. The units require at least 1/2 gallon per
minute for the LS-I5IIE and 1-1/2 gallons per minute for the LS-55IIE. Make sure this amount of water is
passing through the unit. If the water supply is inadequate, the unit will not turn on.
3. Verify that the flow switch IFLS is performing properly. Check for 24 V.D.C. between wire # 11 and wire # 8
on pin 15 on the temp board. If no voltage exists, turn off your water supply and service the flow switch (see pg.
7). It is located down low inside the front panel of the still (it is brass colored and labeled "Gems" on it).
4. If after cleaning the flow switch (and turning the water supply back on) the voltage is still not present between
wire #11 and wire #8, temporarily bypass the flow switch by connecting a jumper wire between pin 21 and pin
15 (on the temp board) to see if the heater contactor engages. If the heater contactor engages with the flow
switch bypassed, replace the flows witch.
PROBLEM: Green light on / White light on / Amber light is not on
5. Disconnect the power to the unit.
Check each thermister individually by disconnecting their wires (22 gauge black and white twisted pairs) from
the temp board. One set is on pins 1 and 3, and the other set is on pins 2 and 4. Measure the resistance between
the black and white wires. The following values should be obtained:
Ambient Temperature
Resistance
(degrees) (kilo-ohms)
60°F (16° C) 136 kΩ
77°F (25°C) 90 kΩ
100°F (38°C) 52.5 kΩ
240°F (115°C) 3.9kΩ
If one or both of the readings do not fall within this range, the thermister(s) should be replaced.