Set Appliance State:

Mains Power Off
Use Insulation Mat as required
Set Multimeter to AC Volts Set meter to measure AC Volts
WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure
Mains Power On

Measurement:

Set CH to ON at programmer.
Measure voltage between Grey wire (top connector) and Neutral (bottom connector) of X15.
Mains voltage expected.