Physitemp Instruments BFS-30VT - Manual (Page 7)

6. Troubleshooting
1. Controller display fails to illuminate when power is turned on.
Check power cord continuity from the AC outlet to the input socket on the rear of the con-
troller. Check the fuse next to the AC input socket in the rear panel. If these are both OK
try a different AC outlet.
2. Fault Condition lamp is illuminated
As a safety feature, this unit has power supply short circuit protection. In the event that the
output becomes short circuited by a wiring fault, a protection circuit built into the power
supply senses the increase in the current and shuts off the output power. Before output
power can be restored to the controller the AC power supply must be turned off and the
fault condition corrected. Consult our engineering department for further details
If the PTU-3 or ECV-1 is being used, check for adequate water flow as described in
Section 5 above. Touch the silver heat sinks on the underside of the refrigeration bath
cautiously to see if yhey are hot to the touch - this would indicate a low or inadequate flow
rate.
If water flow is OK, the stage or controller may be defective. In order to check the stage,
turn off the power to the controller and remove the stage connection from the rear of the
controller by turning the collar in an anticlockwise direction. An ohmmeter will be required
to make several readings on the stage connector. Once the connector has been removed
the pin numbers are visible as slightly raised numerals on the face of the connector.
Between pins 1 and 2 1 - 3 ohms
3 and 5 100 - 110 ohms
6 and 7 45 - 55 Kilohms
If the readings you obtain do not fall within these ranges please consult our engineering
department for instructions.
3. Controller display is illuminated but module does not cool
Check the setting of the set temperature and adjust if necessary using the instructions
provided in Section 5. If the set temperature is OK check the connector to the module
cable on the rear of the controller and the fault condition light on the front of the controller.
If the fault light is on follow instructions for fault condition number 2.
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