Protection Relays
Voltage Monitoring Relays
50R SERIES
Single-phase voltage monitor
Description
The 50R Series single-phase voltage monitor has a voltage-
sensing circuit which constantly monitors the single-phase
power for a low voltage condition. Single-phase motors on fans,
compressors, air conditioners, heat pumps, well pumps, sump
pumps and small conveyor motors are all applicable to the
50R Series.
When a harmful condition is detected, the MotorSaver’s output
relay is deactivated after a specified trip delay. The output relay
reactivates after power line conditions return to an acceptable
level and a specified amount of time has elapsed (restart
delay). The trip delay prevents nuisance tripping due to rapidly
fluctuating power line conditions.
Wiring Diagram
Features & Benefits
FEATURES
Proprietary voltage
sensing circuitry
Adjustable trip delay
(-3 models) and restart
delay (-2 models) settings
BENEFITS
Constant monitoring of single-phase power for a
low voltage condition
Prevent nuisance tripping due to rapidly fluctuating
power line conditions and allows staggered start up
of multiple motors, after a fault, to prevent a low
voltage condition
Trips and resets at a fixed percentage of the
setpoint: trip 110%, reset 107%.
Eliminates the need for a control transformer to step
voltage down to 120 - 240V for a control circuit
50R
High voltage detection
(-9 models)
600V rated relay
contacts available
on some models
Ordering Information
MODEL
LINE VOTAGE
DESCRIPTION
50R-100
50R-100-2
50R200
50R2002
50R2003
50R20029
50R400
50R4002
50R4003
50R40029
95-120VAC
95-120VAC
190-240VAC
190-240VAC
190-240VAC
190-240VAC
380-480VAC
380-480VAC
380-480VAC
380-480VAC
Fixed trip and restart delay
Fixed trip and variable restart delay (manual, 2-300s)
Fixed trip and restart delay
Fixed trip and variable restart delay (manual, 2-300s)
Fixed restart and variable trip delay (2-30s)
Fixed trip and variable restart delay (manual, 2-300s) plus high voltage detection
Fixed trip and restart delay
Fixed trip and variable restart delay (manual, 2-300s)
Fixed restart and variable trip delay (2-30s)
Fixed trip and variable restart delay (manual, 2-300s) plus high voltage detection
© 2016 Littelfuse Protection Relays & Controls
www.littelfuse.com/50r
Rev: 1-A-062716
Protection Relays
Voltage Monitoring Relays
50R SERIES
Specifications
Input Characteristics
Line Voltage
50R-100
50R200
50R400
Frequency
Functional Characteristics
Low Voltage:
Trip (% of setpoint)
Reset (% of setpoint)
Delay Time (Nominal)
Trip
Restart (low voltage)
Restart (complete power loss)
Output Characteristics
Output Contact Rating
(SPDT - 1 Form C)
50R-100, 50R200
Pilot Duty
General Purpose
50R400
Pilot Duty
General Characteristics
Ambient Temperature Range
Operating
Storage
Maximum Input Power
Relative Humidity
Terminal
Torque
Wire Size
Electrostatic Discharge (ESD)
Fast Transient Burst
Transient Protection
(Internal)
Safety Marks
UL
CE
Dimensions
Weight
Mounting Method
95-120VAC
190-240VAC
380-480VAC
50*/60Hz
Special Options
Opt. 2: Variable Restart Delay
Opt. 3: Variable Trip Delay
Opt. 9: High Voltage
Detection Operating Points
Trip (% of Setpoint)
Reset (% of Setpoint)
Manual, 2-300 seconds
2-30 seconds
110%
107%
*Note: 50Hz will increase all delay timers by 20%
90%
93%
4 seconds
2 seconds
2 seconds
480VA @ 240VAC
10A @ 240VAC
470VA @ 600VAC
-20° to 70°C (-4° to 158°F)
-40° to 80°C (-40° to 176°F)
5W
10-95%, non-condensing per IEC 68-2-3
7 in.-lbs.
12-18AWG
IEC 61000-4-2, Level 3, 6kV contact, 8kV air
IEC 61000-4-4, Level 3, 3.5kV input power
and controls
IEC 61000-4-5; 1995 ±6kV
UL508 (File #E68520)
IEC 60947-6-2
H
74.4 mm (2.93”);
W
133.9 mm (5.27”);
D
74.9 mm (2.95”)
0.98 lb. (15.68 oz., 444.52 g)
#8 screws
© 2016 Littelfuse Protection Relays & Controls
www.littelfuse.com/50r
Rev: 1-A-062716