above, the fuse is probably bad. Remove the fuse and
test with an ohmmeter.
NOTE: The solid-state relay number 3 is in series with
the relay number 14. In order to make the test described
above for relay 3, close the keypad panel switch SW1
and temporarily jumper the Oil Pump contactor’s normally
open auxillary contact (terminals C to NO). Relay 14’s odd
numbered terminal should be connected to lead 503, but
lead 309 should be disconnected at the odd numbered
terminal of Relay 3.
If the above described circuit also includes a set of nor-
mally open (N.O.) high pressure (HP) relay contacts, tem-
porarily jumper these contacts to complete this test.
Conclude the test described above.
11.
If the compressor motor has been shut down by opera-
tion of the controlling thermostat, or by opening either
the remote, or local switch, and high amperage remains
impressed at Analog sensor terminals number 9 and 10,
the oil pump control will interpret the high amps as in-
dicating that the compressor motor is still running. The
oil pump will continue to run. The circumstances will also
prevent the compressor from restarting until the problem
is resolved.
This condition will occur if the signal converter DC cir-
cuit fails “open” while the unit was operating.
Check the signal converter-to-analog terminal strip wir-
ing and circuitry.
If the signal converter fails in such a manner as to pass
AC volts to the microprocessor the unit will shut down
and the display will signal a motor current fault.
12.
If AC volts is accidently introduced into terminals number
70 and 71, this condition also will cause microprocessor
to see “High Amps” and the operating results will be
similar to those described in paragraph 11.
13. See the text and Figure 28 concerning the Oil Gauge
Transducer operation.
14.
“Waiting for Load” will not normally indicate a hardware
fault. It could, however, be caused by an inadvertent con-
trol setting. If operating conditions seem to warrant chiller
operation, but the machine has not started, review the
control set-up options with particular emphasis on reset.
15.
Wiring from the sensors to the daughter board terminal
strip is composed of stranded, 18 AWG and 22 AWG wire.
Tiny strands may project beyond the terminal to acciden-
tally touch adjacent ground circuits.
No special instruction is required to check wiring
integrity.
IM
403
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41
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