FANUC Alarm SRVO-349 — DCS MCC ON alarm …,…
Error- Hardware
- main contactor (MCC)
- Controllers
- R-30iA / R-30iB
- FANUC class
- SERVO
- Hardware family
- FANUC DCS, main contactor and safety input alarms
Manufacturer wording — DCS MCC ON alarm %x,%x
The manual prints placeholders; your controller fills them in with the real group, axis or number.
FANUC SRVO-349 (“DCS MCC ON alarm …,…”): A command was issued to turn on the magnetic contactor, but the magnetic contactor was not turned on. First check: 1. Replace the E-stop unit. Likely part: Servo amplifier (Servo amplifier) +2 more.
Updated 2026-10-22 · LogrobotLM reference
Description
A command was issued to turn on the magnetic contactor, but the magnetic contactor was not turned on.
Remedy
1. Replace the E-stop unit. 2. Replace the panel board. 3. Replace the servo amplifier.
Field diagnosis
Close command sent to the main contactor, with no closed feedback.
What to check
- Replace the emergency stop unit (contactor included); then the panel board (R-30iA) or the main board after backup (R-30iB); finally the amplifier.
- Note: Contactor coil or its fuse: listen for the contactor clicking when power is applied.
Part to check / replace
FANUC SRVO-349 points to the hardware below — start here before ordering.
Tap a part for every code that points to it — and verify the exact variant for your controller before ordering.
Related codes
Same hardware involved
Indicative field information — the robot manufacturer's manual and safety procedures always prevail. Never bypass a safety device; apply lockout/tagout (LOTO) before any physical intervention. How this reference is built →