ABB E-111: ABB MNS-MCC Error Code E-111

Symptoms

The motor contactor has failed to close when commanded. The motor does not start and the control circuit shows 0V at the contactor coil terminals.

Step 1: Check the control circuit fuse for continuity
Replace if blown; investigate for shorts before re-energizing
Step 2: Measure the voltage at the contactor coil terminals when a start command is given
If voltage is present but the contactor does not close, the coil is faulty
Step 3: Measure the coil resistance with power off and compare to the nameplate value
Replace the contactor if the coil is open or shorted
Step 4: Trace the control circuit from the PLC output through all interlocks to find the open point
Check emergency stops, overload auxiliary contacts, and interlock relays

Reset: After replacing the fuse, coil, or fixing the control circuit, the contactor closes normally on the next start command.

Contactor coil: 24V DC or 120V AC, match to existing (Verify coil voltage before ordering)
Control circuit fuse: 2A or 5A, time-delay type (Match to existing fuse class)
Control relay: Ice-cube or plug-in type, 8-pin (Match socket and coil voltage)

Q: How do I test a contactor coil?
With power off, measure resistance across the coil terminals. A reading of infinity means the coil is open. Compare to the nameplate resistance.
Q: What causes a control fuse to blow?
Shorted wiring, failed coil, or jammed contactor mechanism. Inspect for wire chafing and terminal shorts before replacing the fuse.
Q: Can I replace just the coil?
On some contactors, yes. Check if the manufacturer offers a coil-only spare part. If not, replace the entire contactor.