© 2016 Littelfuse Protection Relays & Controls
www.littelfuse.com/
Rev: 1-A-062716
Protection Relays
Voltage Monitoring Relays
www.littelfuse.com/hlmu
HLMU SERIES
time to reset. If the fault is corrected after the restart delay is
complete, the output energizes immediately. The restart delay
also occurs when line voltage is applied/reapplied.
R = Restart Delay on fault correction. The restart delay begins
when line voltage is reapplied or when a voltage fault is
corrected. This option is normally selected when staggered
restarting of multiple motors on a power system is required.
N = No Restart Delay. 0.6 second initialization delay on
application of line voltage applies.
Restart Notes: All restart options remain reset when the
following conditions are detected:
1. Phase loss (phase unbalance greater than 25%)
2. Average line voltage less than 120VAC
3. Phase reversal
The restart delay begins when the condition is corrected.
LED Operation
The LED flashes green during the restart delay, then glows
green when the output energizes. It flashes red during the trip
delay then glows red when the output de-energizes. It flashes
red/green if phase reversal is sensed. If a fault is sensed during
the restart delay, the LED will glow red during that portion or the
full restart delay.
Accessories
LPSM003ZXID (Indicating),
LPSM003Z (Non-indicating) Fuse Holders
Littelfuse POWR-SAFE Dead Front holders
provide optimum protection to personnel for
Class CC and Midget-Style fuses. 600 VAC/DC
0KLK002.T Midget Fuse (2 Amp)
10 x 38 fast acting, high-interrupting capacity,
current-limiting type fuse. 600 VAC/500 VDC
C103PM (AL) DIN Rail
35 mm aluminum DIN rail available in a 36 in.
(91.4 cm) length.
P1023-20 DIN Rail Adapter
Allows module to be mounted on a 35 mm DIN
type rail with two #10 screws.
Specifications
Line Voltage
Type 3-phase delta or wye with no connection
to neutral
Operating Voltage
200 - 480VAC Range Voltage Adj. Range Frequency
240 200-240VAC 50 or 60Hz
380 340-420VAC 50Hz
480 400-480VAC 60Hz
Line Voltage Max. 550VAC
AC Line Frequency 50/60 Hz automatically detected
Phase Loss ≥ 25% unbalance
Response Time ≤200ms
Undervoltage &
Voltage Unbalance
Type Voltage detection with delayed trip &
automatic reset
Overvoltage
Trip Voltage 109 - 113% of the adjusted line voltage
Reset Voltage ≅ -3% of the trip voltage
Undervoltage
Trip Voltage 88 - 92% of the adjusted line voltage
Reset Voltage ≅ +3% of the trip voltage
Voltage Unbalance
Trip Setpoint Adjustable 2 - 10% or specify fixed unbalance
of 2 - 10% in 1% increments
Reset on Balance ≅ -0.7% unbalance
Trip Delay
Active On Over/undervoltage, voltage unbalance,
over/under frequency
Range Adjustable from 1 - 30s or specify fixed
delay 1 - 30s in 1s increments
Tolerance ± 15%
Restart Delay
Range Adjustable from 0.6 - 300s; if no restart
delay is selected a 0.6s initialization
delay applies
Tolerance ± 15%
Over/Under Frequency ±4%; Reset ±3%; 50/60 Hz
Phase Sequence A, B, C, L1, L2, L3
Response Time-Phase
Reversal & Phase Loss ≤200 ms
Reset Automatic
Output
Type Isolated Electromechanical Relay
Form DPDT
Rating 10A resistive @ 240VAC;
8A resistive @ 277VAC; NO-1/4 hp @ 120VAC;
1/3 hp @ 240VAC
Life Mechanical - 1 x 10
6
Electrical (at 10A) - DPDT - 1 x 30
3
Protection
Phase Reversal/Failure ASME A17.1 Rule 210.6
Motors and Generators NEMA MG1 14:30, 14:35
Surge IEEE C62.41-1991 Level B
Isolation Voltage ≥ 2500V RMS input to output
Circuitry Encapsulated
Mechanical
Mounting Surface mount with one #10 (M5 x 0.7) screw
Note: 0.25 in.(6.35 mm) spacing between
units or other devices is required
Dimensions H 76.7 mm (3.0”); W 50.8 mm (2.0”);
D 41.7 mm (1.64”)
Termination Screw terminal connection up to 12 AWG
(3.3 mm
2
) wire
Environmental
Operating/Storage
Temperature -40° to 60°C / -40° to 85°C
Humidity 95% relative, non-condensing
Weight ≅ 3.9 oz (111 g)
