YORK YK — Circuit breaker has automatically tripped open

The control center shows Circuit breaker has automatically tripped open. The manual prints the message in this one wording only; there are no variants.

The circuit breaker in the drive has tripped open by itself. The manual treats the trip as a fork: it has to be traced either to the Smart Sensor System (SSS) or to an over current or ground fault. The color of the SSS indicator on the drive shows which of the two origins applies, and each origin leads to its own course of action.

• SSS indicator black (Fig. 2 shows the example): the trip came from an over current or a ground fault.
• SSS indicator red (Fig. 3 shows the example): the SSS has signalled a fault, and JCI Service is brought in for a proper evaluation.

1. Carry out the Safe Entry Procedure before any other work.
2. Locate the SSS indicator on the drive; Fig. 1 in the manual marks its position.
3. Read the color of the indicator.
4. Red: the SSS has signalled a fault — bring in JCI Service so the fault is evaluated properly.
5. Black: the trip is an over current or ground fault, and the electrical checks that follow apply.
6. Run a resistance test on the input power fuses.
7. Check that the circuit breaker settings agree with the values given in the referenced service manual for this unit — the forms are listed under settings.
8. Look over the VSD for outward signs of a ground fault, examining the input inductor, the input capacitor assembly, and the rectifier assembly.
9. Megger the input inductors, phase to phase and phase to ground; fit a new inductor if the reading calls for it.
10. Check the common mode fuses. If any have opened, confirm that the customer power wiring for ground and neutral is correct, then change the blown fuses.
11. Look at the common mode and input capacitors for damage or overheating, and change components as needed.
12. Resistance-test every rectifier and every inverter, and change out any part that fails.
13. If every power fuse failed, change all of the power fuses together with all of the rectifier assemblies; if only some fuses failed, change all of the power fuses plus the rectifier assemblies in the phases whose fuses failed. In either case, also change the inverter in any position where its resistance test failed.
14. With the failed parts changed, begin the repairs.

• Every circuit breaker setting must match the value given in the referenced service manual.
• Form 160.78-M3 covers the M1 motor application.
• Form 160.84-M3 covers the M2 and M6 application.
• Form 160.00-M10 covers YK applications.