Set Appliance State:

Mains Power Off
Set Multimeter to AC Voltage Set meter to measure AC Volts
Purge Switch in NORMAL position
HW Switch in OFF position
CH Switch in OFF position
WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure
Mains Power On

Measurement:

Measure the Voltage across Mains (L) (Brown wire) connection 1 and Mains (N) (Blue wire) connection 3 on the Main Terminal Block.