Applicable Systems
Powerpack 2
Symptoms
The battery system reports a relay contact weld. A main contactor has welded contacts, preventing disconnection.
Possible Causes
- Contact arcing from high current interruption
- Contactor aging and contact degradation
- Excessive inrush current welding the contacts
Troubleshooting Steps
- Step 1: Test the contactor for proper open and close operation
Contactor operates correctly - Step 2: Inspect contacts for welding or pitting
Contacts are clean and separate properly - Step 3: Replace the welded contactor
New contactor operates reliably
How to Reset
To reset: Replace the faulty contactor, then clear the alarm.
Source: Tesla Powerwall Installation Manual, Tesla Inc.
Category: Battery