Rockwell Automation 2364E Non-Regenerative DC Bus Supply Unit (NRU) - Manual (Page 87)

Publication 2364E-5.01 April 2002
NRU Details C-7
Phase-Loss Relay The phase-loss relay monitors the system for undervoltage,
overvoltage, and phase unbalance occurrences. Figure 10 illustrates
the phase-loss relay wiring diagram and defines the relay terminals.
Figure 10
Phase-Loss Relay Wiring Diagram
Installation and Setup
1. Set initial settings on the three knobs as follows:
UNDERVOLTAGE and TIME DELAY ON UNDERVOLTAGE
to minimum (CCW); IMBALANCE to maximum (CW).
2. Connect the fused 3-phase line voltage to terminals A, B, and C
on the D65 - see Figure 10. A connection to the neutral is not
required in Wye systems. DO NOT connect wires to the output
terminals until later. (Step 7).
3. Apply Line Voltage. The LED indicator should illuminate and
stay steady. If the LED flashes, a fault condition exists and must
be corrected. Check to see if all phases are present. REMOVE
LINE VOLTAGE, and switch any two of the line voltage
connections to insure the phase rotation is correct. Reapply line
voltage to check for correct phase rotation.
4. REMOVE LINE VOLTAGE for Steps 4-6. Set the
UNDERVOLATAGE dial. This setting should be the same as the
minimum operating voltage for the equipment to be adequately
protected.
5. Set the TIME DELAY ON UNDERVOLTAGE dial. This is the
maximum time period that an undervoltage condition should
exist. Too short a setting will cause nuisance tripping if there are
momentary dips in the line voltage. Too long a setting could
cause damage to the equipment. Note that the setting should be at
least slightly longer than the time a 3-phase motor is drawing its
inrush current. This will void a nuisance tripping caused by the
starting current.
A C B 11 21
12 14 22 24
A C B
Phases