Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Disconnect inline connector at transformer
Measurement:
Test 1:
Measure the resistance between the blue and brown wires of the black cable at the disconnected plug.
Resistance should be approximately 33Ω, plus the resistance of meter test leads.
Measure the resistance between the brown wire of the black cable to a suitable earth point.
Resistance should be greater than 1MΩ (or O.L.)
Test 2:
Measure the resistance between the blue and brown wires of the white cable at the disconnected plug.
Resistance should be approximately 0.5Ω, plus the resistance of meter test leads.
Measure the resistance between the brown wire of the white cable to a suitable earth point.
Resistance should be greater than 1MΩ (or O.L.)
Measure the resistance between the blue and brown wires of the black cable at the disconnected plug.
Resistance should be approximately 33Ω, plus the resistance of meter test leads.
Measure the resistance between the brown wire of the black cable to a suitable earth point.
Resistance should be greater than 1MΩ (or O.L.)
Test 2:
Measure the resistance between the blue and brown wires of the white cable at the disconnected plug.
Resistance should be approximately 0.5Ω, plus the resistance of meter test leads.
Measure the resistance between the brown wire of the white cable to a suitable earth point.
Resistance should be greater than 1MΩ (or O.L.)
Isolate as per TOPs P4
and refit as necessary