Tweco PAK 200i - Manual (Page 145)

PAK 200i
Manual 0-5335 APPENDIX A-65
4. To test TS2 remove J2 from the Relay board and measure the resistance between pins 4 & 6 of the J2 harness
connector. The resistance varies from about 33K ohms at 0 degrees C to about 12K ohms at 20C to 5.3K ohms
at 40C.
5. If TS� is within the correct range the problem may be with the Relay board or the CCM.
a. The output from the relay board going to the CCM is on pin 30 of the 40 pin ribbon cable (J4 of Relay
board to J23 of the CCM I/O board). It is an analog voltage that should range between 0.44V at 0 deg
C to 1.6V at 40C. If it is confirmed that the room ambient is not above 40C and Ambient temperature
signal at pin 30 is higher than 1.6V then the Relay board is defective.
b. If Ambient temperature signal at pin 30 is OK, less than 1.6V, and the room ambient is not above 40C
then the CCM is bad.
265-270 Inverter No Input Power
There are several digital signals on the ribbon cables between the inverter sections and the CCM that involve
some level of voltage. These include AC_INPUT_FLT\, INVERTER _FLT\, OVERTEMP_FLT\ and POWER_
PRESENT. Normally all of these should be high. Before power is applied to the inverter modules the CCM
has already performed a continuity check to see if that section is in place and it’s ribbon cable connected (code
224 & 237). As soon as power is applied to the inverter modules the CCM checks these 4 signals and, having
already confirmed there is an inverter whose ribbon cable is connected. If it finds none of the signals have volt-
age, it assumes there is no power into the section or something is wrong with that inverter section’s bias power.
Possible causes:
• The 3 input phases, J103-105 to that inverter section not connected.
• The circuit breaker CB2 providing the 120 VAC to the contactor (and Remote Arc Starter) has tripped.
• The contactor powering that section (and others) defective.
• Relay board defective.
• Inverter defective.
• CCM defective.
Troubleshooting:
1. Check that the input power cables are connected to the inverters.
2. Check if the contactor for that section (W1 for 1A, 1B, 2A; W2 for 2B, 3A, 3B) is energized.
a. There is a rectangular section in the middle of each contactor top that can be used to attach auxiliary con-
tacts. This can also be an indicator of contactor operation as it pulls in when the contactor is energized.
b. Check for CB2 on the rear panel being tripped. The white button marked “5” indicating it’s 5 amps, will
pop out if tripped. Reset it and if it pops out again something (contactor coil?) may be shorted.
c. Measure for 120 VAC on the contactor coil. If present, but the contactor isn’t pulled in, it’s probably a
defective contactor.
3. On the Relay board D22, CONTACTOR ON LED (green) next to relay K1 lights if K1 is being told to energize.
a. If it’s on check for 120 VAC between J8-1 and J8-9. If present the relay board is OK.
b. If D22 is on but 120 VAC is not present at J8-1 and J8-9 (make sure meter is set for ACV) then the relay
board is defective.
c. D22 is not on, go to the 40 pin ribbon cable test connector and measure voltage on pin 17 (relative to
TP1 on either the Relay board or the CCM I/O Board). It should be low, less than 1 volt. If it is the relay
board is likely bad. If it’s high, about 24VDC then the CCM may be bad, not telling the contactor to turn
on.