Relay Features - GE 239 Instruction Manual

1 OVERVIEW
239 INSTRUCTION MANUAL 1 OVERVIEW
The GE Multilin 239 relay is designed to fully protect three phase AC motors against conditions
which can cause damage. In addition to motor protection, the relay has features that can protect
associated mechanical equipment, give an alarm before damage results from a process malfunction,
diagnose problems after a fault and allow verification of correct relay operation during routine main-
tenance. Using the ModBus serial communications interface, motor starters throughout a plant can
be connected to a central control/monitoring system for continuous monitoring and fast fault diagno-
sis of a complete process.
One relay is required per motor. Since phase current is monitored through current transformers,
motors of any line voltage can be protected. The relay is used as a pilot device to cause a contactor
or breaker to open under fault conditions; that is, it does not carry the primary motor current. When
the over temperature option is ordered, up to 3 RTDs can be monitored. These can all be in the sta-
tor or 1 in the stator and 2 in the bearings. Installing a 239 in a motor starter for protection and moni-
toring of motors will minimize downtime due to process problems.
PROTECTION
• Overload (15 selectable curves)
• Short circuit
• Locked rotor
• Stall / mechanical jam
• Repeated starts (Mod 505)
• Single phase / unbalance
• Ground fault
• Overtemperature (Thermistor & 3 RTDs)
• Undercurrent
• Overload warning
• Breaker failure
GE Multilin
Courtesy of NationalSwitchgear.com
FEATURES
• Status/current/temperature display
• Fault diagnosis
• Trip record
• Memory lockout
• Thermal capacity / load% / RTD analog
output
• Trip / alarm / auxiliary / service relay out-
puts
• Motor Running Hours
• Motor maximum current on last start
• Simulation mode for field testing
• Clear LCD display
• RS485 Modbus communications interface
• AC/DC control power
• Compact size, fits most starters
• Update options and/or MODs in field
• CSA/UL Approved
239 Motor Protection Relay
1 OVERVIEW

1.1 239 RELAY FEATURES

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