MGE UPS Systems 3.5 to 21 kVA N+1 Manuale Utente

The system provides three alarm signals, namely, Utility alarm, Minor alarm, and Major alarm.

◗

Utility alarm – Utility alarm is ON when utility input voltage is lost/out of tolerance.

◗

Minor alarm – The system sends out this signal to indicate something is not functioning properly, but invert-

er can still maintain the load.

◗

Major alarm – Whenever load is lost power and the system is energized.

For alarm connection, see Table 2-5.

There are three alarm relays.  All relays are “form C” type, that is, the relay has a normally open and a normally

closed contact set.

The Major Alarm relay will be energized when the system is operating properly, that is, power is being supplied to

the load either from the Inverter or from the Utility.  There are two sets of “form C” contact sets on the Major Alarm

relay.

The Minor Alarm relay will be de-energized, and will be energized for the alarm condition.  A minor alarm will be

issued if the system is not operating properly.  Such an alarm will be issued during overload, battery voltage not

within specified limits, power modules over temperature and module fault.

The Utility Alarm relay will be de-energized during normal operation and will be energized for the alarm condition.

This alarm will be issued if the utility voltage is not within specified limits or the input frequency is not within proper

limits.

The table below shows the alarm and the non-alarm terminal block connections.  This terminal block is located in

the top, left side of the receiver cabinet.  The small front panel must be removed to gain access to the terminal block.

MAJOR ALARM ---

X

X

MAJOR ALARM ---

X

X

No Major Alarm ---

X

X

No Major Alarm ---

X

X

Minor Alarm ---

X

X

No Minor Alarm ---

X

X

Utility Alarm ---

X

X

No Utility Alarm ---

X

X

“X” indicates a short circuit between J21 terminal block points.