Product Overview

© 2016 Littelfuse Protection Relays & Controls
Protection Relays
Voltage Monitoring Relays
www.littelfuse.com/201a
Rev: 1-A-062116
Description
The 201A is a 3-phase, auto-ranging, dual-range voltage monitor
that protects 190-480VAC, 50/60Hz motors regardless of size.
The product provides a user selectable nominal voltage setpoint
and the voltage monitor automatically selects between the
200V and 400V range. The 201A includes advanced single LED
diagnostics, where color and light patterns distinguish between
faults and normal conditions.
This unique microcontroller-based voltage and phase-sensing
device constantly monitors the 3-phase voltages to detect
harmful power line conditions. When a harmful condition is
detected, the 201A’s output relay is deactivated after a specified
trip delay. The output relay reactivates after power line conditions
return to acceptable levels for a specified restart delay time.
Features & Benefits
FEATURES BENEFITS
Proprietary
microcontroller
based circuitry
Constant monitoring of single-phase, low voltage,
voltage unbalance, phase reversal, harmful power
line conditions. High voltage monitoring optional.
Compact design for 8-pin;
DIN rail or surface mount
Allows flexiblility in panel installation
Auto-sensing wide
voltage range
Automatically senses system voltage between
190 - 480VAC. Saves setup time.
Advanced LED
diagnostics
Quick visual indicator for cause of trip. LED
indications include: normal operation, power-up
restart delay, reverse-phase trip, unbalance/
single-phase trip, high/low voltage trip
Accessories
OT08PC Octal 8-pin Socket
8-pin 35mm DIN rail or surface mount. Rated at
10A @ 600VAC. Surface mounted with two #6
screws or snaps onto a 35 mm DIN rail.
3-Phase Voltage/Phase Monitor
201A SERIES
Wiring Diagram
201A WITH MOTOR CONTROL
201A WITH ALARM CONTROL
Ordering Information
MODEL LINE VOLTAGE DESCRIPTION
201A
190-480VAC
DIN rail or surface mountable
201A-9
190-480VAC
Includes high voltage detection. DIN rail or
surface mountable