Tweco Troubleshooting Power Supply - Manual (Page 20)

20
Power Supply PCB
PCB5, WK-5602A, takes the signal /TEMP_ERR from the inverters on CN6-
14, combines it with signal CHOPPER_TEMP_ERR (units after early 2006) and
inverts it becoming signal /TEMP OK which is sent to the CCM on CN11-8 (J36-
8 on CCM). Signal is low when temperature is OK. If, with the ribbon cable
disconnect from CN6 on PCB5 and the harness from the chopper (if present)
disconnected from CN17, the signal on CN11-8 is not low PCB5 is defective.
CCM
Signal /TEMP OK on J36-8 is active low. If it is low but code 2-3 and the front
panel Temp LED remain on then CCM is defective.
2-4
Power Supply Not Ready
2-4 is set when the signal /READY TO OPERATE, normally active low, is not
true. It is not true during the first few seconds after power on while the input
capacitors are being charged, a time called inrush. /READY TO OPERATE is
also false if the capacitors do not charge up during inrush or if the charge too
high. Missing phase also makes /READY TO OPERATE false but will set the
missing phase code 2-1 instead.
Causes for code 2-4:
• 16 ckt ribbon cable disconnected from CN6 on either PCB5 or inverter.
• Contactor MC1 defective so no power to inverter or CN9 on PCB5
disconnected so inverter(s) get no power.
• PCB4, Detector PCB, defective
• PCB7, Relay PCB, defective.
• Inverter defective.
• PCB5 defective.
• CCM defective
The power supply includes circuits to determine if the inverters are properly
configured for the input voltage that is being applied. Each inverter has a Voltage
Change PCB with 2 headers, CN1 & CN2. CN1 has jumper betweens pins 1 & 2,
CN2 between pins 3 & 4. A harness connector plugs into one of them on each
inverter, CN1 if configured for 230V or CN2 for 460V. The other end of the
harness connects to CN4 on PCB4. The harness is arranged so that a circuit is
completed when each inverter is configured for the same voltage. If neither the
230 or the 460 circuit is completed as is the case if one inverter is set for a
different voltage than the other, then a signal INPUT NG is sent to PCB5. The
simplified schematic below shows when there are 2 inverters but with a third
inverter it is similar.