12 remote alarm 2-19, 1 alarm relays 2-19, Owner’s manual – MGE UPS Systems 3.5 to 21 kVA N+1 User Manual
Page 37
Installation & Operation
page 2 — 19
Owner’s Manual
2.12
Remote Alarm
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.
2.12.1 Alarm Relays
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.
Table 2-5: Alarm Connections.
J21 terminal block screw position ---
1
2
3
4
5
6
7
8
9
10
11
12
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.