Finish Thompson BE-15/15C - Manual (Page 17)

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4. Cooling control system may be faulty (units F91 through I91). The TAS1 temperature sensor is
located on the top of the Process Tank (It is a 1/2” diameter white ceramic sensor with a brass hex
base and two wires #13 and #19 connected to it) is a “normally open” switch. When the tank reaches
180
F, the sensor closes, energizing the coil on the Chiller/pump contactor. This allows the cooling
water to flow through the Condenser.
Hint: If the pump’s motor turns on, TAS1 is operating OK.
 Place a jumper wire across TAS1. If the Process Tank is over 180, and the Chiller and pump
motor start, replace TAS1.
 If the Chiller and pump motor do not start after jumping TAS1, check for a faulty contactor in the
unit’s circuit box. The contactor is the upper right component. Determine whether the coil is
open (check for resistance between wires # 18 and #19) or if the contacts are bad. Replace the
contactor if necessary.
Cooling system problems with a BE-15C “Air Cooled”:
1. Pump Reservoir is low. This is the most common cause. The reservoir only needs to be about 1/2”
low to cause poor coolant circulation through the Condenser. Top off the reservoir until it overflows
from the Processed Glycol Hose.
2. Unit installed in too warm of an area. If the ambient temp around the BE unit gets above 100
F, then
the unit can overheat. Verify good, cool ventilation in the installation area. Avoid installations in
small enclosed rooms or near space heaters and heated parts washers.
3. Improper air circulation. Clean the finned-tube surfaces of the Radiator by blowing compressed air
through the fins from the inside to the outside. Clean the fins with a degreaser if necessary. Also
verify that the rear of the unit is installed a minimum of one foot from a wall. Also be sure that
objects are not stacked around the rear of the Radiator (that will impede air circulation).
4. Radiator blocked internally from debris or scale. One hint that the Radiator is restricted would be if
the air blown through by the fan does not feel warm (after the machine has been running for a while).
Perform a flush of the Pump Reservoir and Radiator as outlined in the “Maintenance - Semi-
annually” section. If the low flow or blockage persists, perform a Radiator flush using a
commercially available flushing solution. Also, worn, kinked, or deteriorated hoses can restrict flow.
Replace any suspect hoses with standard 1/2” automotive heater hose.
5. Vacuum/circulation pump not circulating the liquid properly. While the unit is off, tilt the motor and
pump out of the Pump Reservoir. There is supposed to be a gray elbow attached to the pump’s
discharge. The Aspirator is attached to this elbow, as well as a hose. Verify that the elbow has not
come loose from the pump, and that the hose is attached to the elbow as well and not kinked or worn.
Replace any suspect or worn hoses.