Set Appliance State:

Mains Power Off
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:

Test 1:
Measure the voltage across the Live (marked L) and the Earth
on the main connector block at the front of the control box.
Test 2:
Measure the voltage across the neutral (marked N) and the Earth on the main connector block at the front of the control box.