IQ200 relay welded

How it presents

Symptom

Blink IQ200 reports a welded or stuck main relay, or fails its weld-detect self-check, typically right after a hard fault-current event or years of high-cycle depot duty. The stall latches Faulted and stays there — FreeVend and app-initiated sessions are both blocked — while neighboring pedestals on the same pad usually keep working normally, which helps rule out a site-wide power event.

Root causes (by observed frequency)

1. #1 Main relay contacts welded closed (or stuck open) after a fault-current event or normal contact wear at end of life

   Most common on high-cycle depot/fleet sites; check cycle count if the controller logs it

2. #2 Weld-detect auxiliary feedback contact miswired, loose, or dirty after a prior service visit

   A false weld-detect can look identical to an actual weld; check the aux wiring before condemning the relay

3. #3 Control board falsely reporting weld-detect due to a firmware or sensing fault

   Confirm with a manual continuity check across the relay contacts before trusting the board's own diagnosis

4. #4 Upstream breaker nuisance tripping that forced repeated hard relay makes/breaks under load

   Check breaker trip history; frequent hard makes accelerate relay wear

Diagnostic procedure

1. 1. Capture the exact HMI/Cloud fault code and confirm whether the issue is isolated to one pedestal or affects the whole pad

   Expected: Fault isolated to one pedestal; peers report normal status

   Tools: Blink portal

2. 2. LOTO the unit and manually check contact continuity/resistance across the main relay with power removed

   Expected: Contacts open cleanly with no continuity when de-energized (or closed cleanly with low resistance when commanded closed)

   Tools: LOTO kit, DMM

3. 3. Inspect the weld-detect auxiliary feedback wiring and connector for looseness, corrosion, or miswiring

   Expected: Aux contact wiring intact and correctly landed per OEM diagram

   Tools: inspection light, OEM wiring diagram

4. 4. Check the upstream breaker's trip history and lug torque for evidence of repeated hard-fault events

   Tools: panel schedule, torque wrench

5. 5. Replace the relay assembly if mechanically welded or worn, then retest the weld-detect self-check before returning to service

   Tools: OEM relay kit

The fix

Confirm the weld mechanically before replacing the relay, and never jump or bypass weld-detect just to clear the fault code.

• Main relay / contactor kit

  Blink OEM kit only

  blink-iq200-relay

1. Lock out and tag out the unit, then verify zero energy at the relay before any inspection or replacement work.
2. Confirm whether the relay is truly welded using a manual continuity check, rather than trusting the weld-detect code alone.
3. Replace the relay assembly if welded or worn, and verify the auxiliary weld-detect feedback wiring is correctly landed during reassembly.
4. Restore power, confirm the weld-detect self-check passes cleanly, and run a validation session of at least five minutes before closing the ticket.