Wm63 Tripping Rcd

This thread was marked as solved. Here's a summary of the problem and the fix, generated from the discussion below.

Hotpoint Aquarius WM63 trips RCD as motor circuit is engaged

The problem

An 11-year-old Hotpoint Aquarius WM63 was tripping the RCD almost immediately after a wash programme started, just after a small amount of water entered. With the motor wiring loom disconnected, the machine continued to fill without tripping. Replacing the motor brushes did not cure the fault.

Likely cause

Most likely a motor insulation fault, with the motor identified as the main suspect because the tripping stopped when it was disconnected. The accepted reply said carbon dust from worn brushes can cause tripping, but as the motor had been stripped and cleaned, the armature itself or possibly the field coil was then considered the more likely source of low insulation to earth. This was not confirmed by test results.

What fixed it

Carry out a proper insulation resistance test with an insulation tester (megger) to confirm which component has broken down. The discussion did not confirm a completed repair or whether the motor was replaced.

Checks to try

• RCD tripped very quickly after programme start
• Machine continued filling when the motor wire loom was disconnected
• Motor brushes were replaced with no improvement
• Motor/armature was removed, cleaned and continuity checked
• Armature/commutator was reported to appear OK

Parts or tools mentioned

• motor brushes
• insulation test meter (megger)
• reconditioned motor priced at £30