Finish Thompson BE-15/15C - Manual (Page 18)

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6. Vacuum/circulation Pump motor is not coming on.
 For units E91 to E92, check the pump motor’s contactor in the unit’s circuit box (upper right
contactor). There should be 240 volts at wires #8 and #9 when the contactor is engaged. If the
contactor is not engaged, verify there is 120 volts to the coil (wires #18 and #19). If so, the coil is
defective, and the contactor needs replaced.
If the pump motor’s contactor is functioning, determine whether the pump motor is defective. Attempt to
turn the motor’s fan with a screwdriver’s blade through the motor’s fan cover. If the fan will not turn,
the motor’s bearings may have seized. Replace the motor or have it rebuilt. Refer to the
“Vacuum/circulation Pump Servicing” section of this manual.
 For units F92 or newer, check the contactor in the unit’s circuit box. There should be 240 volts at
wires #8 and #9 when the contactor is engaged. If the contactor is not engaged, verify there is 240
volts to the coil (wires #13 and #18). If so, the coil is defective, and the contactor needs replaced. A
defective contactor would also prevent the unit from heating.
If the pump motor’s contactor is functioning, determine whether the pump motor is defective. Attempt to
turn the motor’s fan with a screwdriver’s blade. If the fan won’t turn, the motor’s bearings may have
seized. Replace the motor or have it rebuilt. Refer to the “Vacuum/circulation Pump Servicing”
section of this manual.
Possible Cause 3: TAS4 is too sensitive.
Check whether the temperature of the Distillate Piping and the liquid in the Pump Reservoir. The most
accurate method of measuring the piping temperature is to remove TAS4 from its mount and insert a
temperature probe in its place.
 If TAS4 has opened the piping temperature is less than 150 and the liquid temperature is and less
than 110
, TAS4 is too sensitive. Either replace or desensitize TAS4. Insert a nylon or ceramic
washer (capable of handling temperatures up to 200
) under the hex base of TAS4 before re-installing
to act as an insulator—then only the stud will sense the temperature.
 If TAS4 has opened and the temperatures are higher than allowable, re-check Possible Cause 2.
Possible Cause 4: Process Tank overheating.
Check TAS2. This is a “normally closed” switch threaded into the front of the Process Tank behind the
access panel in the insulation. It is a 1/2” diameter white ceramic sensor with a brass hex base and two wires
(#1L1 and #25 for units K91 or newer, #11 and #12 for E91 or older) connected to it. This switch opens if
the Process Tank reaches 385
F.
 If TAS2 is closed, then proceed to Possible Cause 4.
 If TAS2 is open (while the unit is still hot), check for Residue build-up in the Process Tank.