Electrical Troubleshooting Procedures LTC Repair
wc_tx000429gb.fm 110
7.22 Checking Wiring to/from Ballast(s)
See Graphic: wc_gr003072
Electric shock hazard. Only qualified personnel should conduct this
test. Complete this test with the machine shut down.
At this stage, you should have measured voltage (120V±10%) to the
circuit breaker(s) and no incoming voltage (400V±10%) to the control
panel capacitors. Therefore, if the wiring to the ballast from the circuit
breaker(s) is OK, the same voltage should be incoming to the ballast.
In addition, if the wires from the ballast to the control panel capacitor(s)
are OK, there should be voltage incoming to the control panel
capacitors. If there is not, the ballast has failed; replace it.
To check the wiring:
7.22.1 Turn off the engine.
7.22.2 Remove the control panel front cover.
7.22.3 Remove the screws (a) which secure the control panel and the cover
of the ballast box. Position the control panel/cover of the ballast box (b)
so you can access the wiring to the ballast.
7.22.4 Check the B/Y (black-yellow) wire(s) (c) that run from the circuit
breaker(s) to the ballast. Repair the wiring as needed.
7.22.5 Check the R (red) wire(s) (d) that run from the ballast to the control
panel capacitor(s). Repair the wiring as needed.
7.22.6 Check the Y (yellow) wire(s) (e) that run from the ballast to the neutral
of the terminal strip. Repair the wiring as needed.
7.22.7 If all wiring is OK, the ballast has failed; replace it.
7.22.8 If you had to repair any wiring, recheck the voltage incoming to the
control panel capacitors. See section Checking Incoming Voltage to
Control Panel Capacitor(s).
WARNIN