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KUKA Robot Controller
Power Supply · Basic
KUKA Robot KRC0052 - K1 CONTACT FAIL TO OPEN <KPS number>
The K1 safety contactor has failed to open during a safety circuit check, indicating the contacts are welded or stuck in the closed position. This prevents proper disconnection of power during emergency stops or safety-related shutdowns. The alarm includes the KPS (KUKA Power Supply) number to identify which specific power module or safety circuit is affected.
KRC0052
KUKA Robot KRC0052 - K1 CONTACT FAIL TO OPEN <KPS number>
K1 CONTACT FAIL TO OPEN <KPS number>
The K1 safety contactor has failed to open during a safety circuit check, indicating the contacts are welded or stuck in the closed position. This prevents proper disconnection of power during emergency stops or safety-related shutdowns. The alarm includes the KPS (KUKA Power Supply) number to identify which specific power module or safety circuit is affected.
Common Causes
- K1 contactor contacts welded due to electrical arcing or high inrush current
- Contamination or oxidation on contactor contacts preventing proper separation
- Mechanical jamming of the contactor plunger or movable contact arm
- Insufficient contact pressure or worn contact springs in the K1 relay
- Voltage surge or transient spike causing contact fusion during switching
Troubleshooting Steps
- 1Verify the alarm persists by performing a full system power cycle and safety system reset through the teach pendant
- 2Inspect the K1 contactor physically for visible signs of pitting, burning, or welding marks on the contact surfaces
- 3Check the coil voltage and resistance of the K1 contactor using a multimeter to ensure proper electrical operation
- 4Examine the mechanical linkage and plunger movement of the K1 contactor for sticking or binding conditions
- 5Test the safety circuit continuity and switching response using KRC diagnostics or KPS-specific testing procedures
- 6Replace the K1 contactor assembly if welding is confirmed, as contacts cannot be reliably restored once fused
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