Littelfuse EL731 Series User Manual
El731 series, Protection relays & controls, Ac mode dc mode

Protection Relays & Controls
© 2013 Littelfuse Protection Relays & Controls
CT1
CT2
L2
L1
GROUNDED
AC SUPPLY
EL731 SERIES
(AC/DC Sensitive
Earth-Leakage Relay)
A
B
C
CT1
L2
L1
EL731 SERIES
(AC/DC Sensitive
Earth-Leakage Relay)
GROUNDED
DC SUPPLY
+
–
Description
The EL731 is a microprocessor-based AC/DC Sensitive
Earth-Leakage Relay that offers complete coverage for all
frequencies from 0-6,000 Hz. Two CTs are required for the
entire frequency range, or one CT can be used for only low-
or high-frequency detection. An RTD/PTC sensor input
allows over-temperature protection. The EL731 offers
metering capabilities, password-protected alarm and trip
settings and optional network communications. It is used to
add low-level ground-fault protection to variable-speed
drives, and to dc currents.
EL731 SERIES
AC/DC Sensitive Earth-Leakage Relay
ORDERING NUMBER
CONTROL
POWER
COMMUNICATIONS
EL731-00-X0
120/240 Vac/Vdc
None
EL731-01-X0
120/240 Vac/Vdc
DeviceNet
™
EL731-02-X0
120/240 Vac/Vdc
Profibus
®
EL731-03-X0
120/240 Vac/Vdc
EtherNet/IP
™
EL731-04-X0
120/240 Vac/Vdc
Modbus
®
TCP
EL731-10-X0
48 Vdc & 24 Vac
None
EL731-11-X0
48 Vdc & 24 Vac
DeviceNet
™
EL731-12-X0
48 Vdc & 24 Vac
Profibus
®
EL731-13-X0
48 Vdc & 24 Vac
EtherNet/IP
™
EL731-14-X0
48 Vdc & 24 Vac
Modbus
®
TCP
EL731-20-X0
24 Vdc
None
EL731-21-X0
24 Vdc
DeviceNet
™
EL731-22-X0
24 Vdc
Profibus
®
EL731-23-X0
24 Vdc
EtherNet/IP
™
EL731-24-X0
24 Vdc
Modbus
®
TCP
Ordering Information
Simplified Circuit Diagram
ACCESSORIES
REQUIREMENT
EFCT Series CT
One Required
AC700-CUA Series Com. Unit
Optional
AC700-SMK Surface-Mount Kit
Optional
Accessories
EFCT Series Earth-Fault Current Transformer
Required zero-sequence current transformer
specifically designed for low level detection.
AC700-CUA Series
Communication Adapter
Optional network-interface and firmware-
upgrade communications adapters field-install
in EL731.
AC700-SMK DIN-rail & Surface-mount
Adapter
EL731 plugs into adapter for back-plane
mounting.
A
A
A
A
AC Mode
DC Mode
Earth-Leakage Protection–Grounded AC or DC Systems
Rev: 4-D-071813
Based on Manual Rev 6-A-042613
Littelfuse.com/el731
Note: When building a part number, replace the “X” with “1” for AS/NZS 2081:2011 Compliant product, “0” otherwise.
For detailed wiring diagram, see adjacent page.