Protection Relays and Controls
© 2017 Littelfuse Protection Relays & Controls
Littelfuse.com/se-703
Ground-Fault Protection–Grounded Systems
Description
The SE-703 is a microprocessor-based earth-fault relay for resistance-
and solidly earthed systems. It offers sensitive earth-fault detection as
low as 25 mA and can be used on systems with significant harmonic
content. The SE-703 provides feeder-level protection or individual-load
protection. The output contacts can be connected for use in protective
tripping circuits or in alarm indication circuits. The analog output can be
used with a PLC or a meter. The SE-703 is specifically designed to be
AS/NZS 2081 compliant to either 2011 or 2002 (see ordering options).
SE-703 SERIES
Earth-Leakage Monitor
Specifications
IEEE Device Numbers Ground fault (50G/N, 51G/N)
Input Voltage See ordering information
Dimensions
H 75 mm (3.0"); W 55 mm (2.2"); D 115 mm (4.5")
Trip Level Settings 25-500 mA
Trip Time Settings INST-500 ms
Contact Operating Mode Fail-safe unless noted
Harmonic Filtering Standard feature
Test Button Standard feature
Reset Button Standard feature
CT-Loop Monitoring Standard feature
Output Contacts Isolated Form A and Form B unless noted
Approvals
CSA certified
, UL Listed (E340889),
CE (European Union), RCM (Australian) unless noted
Compliance AS/NZS 2081:2011 unless noted
Analog Output 0-5 V
Conformally coated Yes
Warranty 5 years
Mounting DIN, Surface (standard)
Panel (with PMA-55 or PMA-60 adapter)
ORDERING NUMBER CONTROL POWER
SE-703-OU 120/240 Vac/Vdc
SE-703-OD 12/24 Vdc
SE-703-OT 48 Vdc
SE-703-03 24 Vac
SE-703-xx-00
1
As above
SE-703-xx-02
1,2
As above
Ordering Information
Simplified Circuit Diagram
FEATURES BENEFITS
Adjustable pickup
(25 - 500 mA)
Adjustable trip setting provides a wide range of low-level
protection and system coordination
Adjustable time delay
(INST- 500 ms)
Adjustable trip delay allows quick protection and
system coordination
Output contacts
Form A and Form B or 2 Form C ground-fault output
contacts for operation of separate annunciation and
trip circuits
Analog output
(0 - 5 V)
Allows for connecting an optional meter (PGA-0500) or
control system
CT-Loop monitoring Alarms when CT is not connected
Contact operating
mode
Fail-safe operating mode for undervoltage applications,
optional non-fail-safe mode available
Harmonic filtering Eliminates nuisance tripping
Non-volatile trip
memory
Retains trip state while de-energized to simplify
troubleshooting
Microprocessor based No calibration required, saves maintenance cost
Universal
power supply
Allows operation in application where one side of PT is
faulted, provides flexibility for numerous applications
Features & Benefits
ACCESSORIES REQUIREMENT
EFCT Series Required
PGA-0500 Optional
PMA-55 Optional
PMA-60 Optional
SE-EFVC Voltage Clamp Optional
Accessories
EFCT Series Ground-Fault Current Transformer
Required zero-sequence current transformer
specifically designed for low-level detection.
PGA-0500 Analog % Current Meter
Optional panel-mounted analog meter displays ground-
fault current as a percentage of the set-point or 5 A.
PMA-60 Series – Mounting Adapter
Required when panel mounting for AS/NZS 2081:2011
compliance
A
A
Rev: 4-C-032917
Based on Manual Rev 12-A-031017
NOTES:
1 Two Form C contacts. CSA and UL certification pending.
2 Selectable fail-safe/non-fail-safe operating modes (AS/NZS 2081:2002 compliant)
CT
L2
L1
GROUNDED
SUPPLY
SE-703 SERIES
(Earth-Leakage Monitor)
(Output contacts
vary by model)
A
B
C
