R-Pro › Field cases › Chillers

Compressor Unresponsive Despite Start Command from Control Panel

Likely causes

Power not applied or circuit breaker tripped

Check: Use multimeter to check in order: main breaker → control panel fuses → terminal voltages. Verify power indicator and panel display illumination

What to do: Reset breaker and restart. If trips again, analyze cause (overcurrent/ground fault) and replace. For blown fuse, replace with same rating and investigate cause

Low pressure interlock — refrigerant pressure below minimum

Check: Measure low-side pressure with gauge manifold. Check controller error code (LP interlock warning). Verify pressure equalization at standstill — if equalized but interlock persists, suspect LP switch fault

What to do: Repair refrigerant pressure drop cause (leak) and recharge. Replace LP switch if confirmed faulty — always verify actual pressure with gauge before final judgment

Oil failure trip (low oil pressure)

Check: Check oil level via sight glass — top up if below minimum mark. Check oil differential pressure switch output signal. Oil filter clogged if ΔP exceeds 0.15 MPa

What to do: Top up oil (must use manufacturer-specified type) → replace oil filter → confirm oil pump operation. Replace oil separator if faulty

Flow switch not activated (flow switch paddle broken)

Check: Verify actual chilled water flow then measure flow switch terminal voltage — if flow normal but terminal open, switch faulty. Broken paddle visible on visual inspection

What to do: Replace flow switch (recommend replacing full switch assembly if paddle broken). Reconnect terminals if wiring connection faulty

Field tip

When unable to start, check controller error codes first — cross-referencing manufacturer manual identifies 70%+ of causes. No error code = check power supply sequentially.

All 565 cases work offline in R-Pro, with error codes for 62 brands and P-T data for 108 refrigerants.

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