THIS EQUIPMENT MUST BE GROUNDED.
To ensure the safe operation of the equipment, it must be installed and
commissioned by qualified personnel in full compliance with the warnings laid down
in these operating instructions.
Take particular note of the general and regional installation and safety regulations
regarding work on dangerous voltage installations (e.g. EN 50178), as well as the
relevant regulations regarding the correct use of tools and personal protective gear.
The mains input, DC and motor terminals, can carry dangerous voltages even if the
inverter is inoperative; wait 5 minutes to allow the unit to discharge after switching
off before carrying out any installation work.
The inverters can be installed in a side-by-side configuration, but a distance of 100
mm (3.94 inches) must be maintained if the inverters are installed on top of each
The inverter must always be grounded. If the inverter is not grounded correctly,
extremely dangerous conditions may arise within the inverter which could prove
Operation with ungrounded (IT) supplies
The MICROMASTER will operate from ungrounded supplies and will continue to operate
if an input phase is shorted to ground. If an output phase is shorted to ground, the
MICROMASTER will trip and indicate F0001.
On ungrounded supplies, it will be necessary to remove the 'Y' capacitor from the inside
of the unit and fit an output choke. The procedure for removing this capacitor is described
in Appendices E
Operation with Residual Current Device
If an RCD (also referred to as ELCB or RCCB) is fitted, the MICROMASTER inverters will
operate without nuisance tripping, provided that:
A type B RCD is used.
The trip limit of the RCD is 300mA.
The neutral of the supply is grounded.
Only one inverter is supplied from each RCD.
The output cables are less than 50m (screened) or 100m (unscreened).
MICROMASTER 420 Operating Instructions