AC/DC Sensitive Earth-Leakage Relays
Littelfuse EL731 Series
- Adjustable time delay for a wide range of low-level protection and system coordination
- Password-protected alarm and trip settings
- Use in AC or DC mode or both
- Use single or combined ranges
- Adjustable trip levels
Description
The Littelfuse EL731 a microprocessor-based AC/DC Sensitive Earth Leakage Relay offering complete coverage for frequencies from DC (0Hz) to 6,000Hz.
Two CTs are required for the entire frequency range, or one CT can be used for only low or high-frequency detection.
Use the EL731 to add low-level earth-fault protection to variable-speed drives and to dc circuits.
An RTD/PTC sensor input allows over-temperature protection for a motor or drive. The EL731 offers metering, password-protected alarm and trip settings and optional network communications.
Note: a Littelfuse DC earth fault detection relay may also be known as a ground fault product.
We are the exclusive NSW supplier of Littelfuse protection relays and controls for the protection, safe control and distribution of electrical power in industrial applications.
32-char OLED display
Earth-leakage metering, setup and programming.
CT-Loop monitoring
Alarms when CT is not connected.
Analog output (4-20 mA)
Connect to DCS. Allows connection to an optional meter (PGA-0520) or control system.
Alarm and trip settings
Detect a deteriorating condition before damage occurs.
Temperature-sensor input
Drive or motor temperature protection.
Harmonic filtering
Eliminates nuisance tripping due to harmonic noise.
Universal power supply
Provides flexibility for numerous applications.
Data sheets and manuals
EL731 Data Sheet EL731 Manual EL731 Profibus Manual EL731 DeviceNet ManualEL731 EthernetIP Interface ManualEL731 Modbus TCP Interface ManualEL731 Firmware Update Instructions
CAD Drawing
EL731 Outline Mounting Detail CAD Drawing
White papers and articles
Industrial Elextrix Article 2015Underground Coal - Going to Ground Article White Paper: Earth-Fault Protection with VFDs
IEEE Device Numbers
AC earth fault (50G/N, 51G/N), DC earth fault (79G), PTC overtemperature (49), RTD temperature (38, 49)
