Owner manual

Publication 2364P-5.01 December 1999
Installation 15-7
Phase-Loss Relay
An NRU in the parallel configuration will be equipped with a phase-
loss relay, which is used to indicate phase loss, phase unbalance,
undervoltage, phase reversal conditions in the 3-phase AC line. The
relay has NO/NC contacts, connections for a reset control, and
jumper connections for setting undervoltage and phase unbalance
tolerances. The relay LEDs indicate AC line conditions and change
of state in the relay.
Figure 15.5
Phase Loss Relay
The system voltage dial should be set to the nominal AC line voltage,
and a restart delay of 0.0 minutes is recommended. Typically, the
normally-open contacts (terminals 1 and 2) will be wired to the fault
circuitry in the NRU, and the normally-closed contacts (terminals 3
and 4) will be wired to TB1-3 and TB1-4 for customer connection.
NO Contacts NC Contacts
Manual
Reset
Common
Undervoltage
Response Curves
Phase Unbalance
Response Curves
Customer-Supplied
Reset Switch
12345
678910
U1 U2 I1 I2
Phase A
Voltage
Phase B
Voltage
Phase C
Voltage
L1 L2 L3
Term inal Definitions
To TB1-3,
TB1-4
To Fault
Circuitry
1
6
2
7
3
8
4
9
5
10
A
B
C
CONTACTS
TRANSFERRED
PHASE
REVERSAL
PHASE
LOSS
PHASE
UNBALANCE
UNDER
VOLTAGE
RESTART
DELAY
0.0
.25
.50
1.0
2.0
3.0
4.0
5.0
SYSTEM
VOLTAGE