Set Appliance State:

Mains Power Off
Set Multimeter to AC Volts Set meter to measure AC Volts
Selector switch set to OFF
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Measure for AC voltage across pins 3 and 4 of the main terminal block.
Expect mains voltage (230 Vac).
Note.
Connection 1 of terminal block is far left when facing appliance front.