
CHAPTER 4: MOTOR MANAGEMENT & METERING THE 239 MOTOR MANAGEMENT RELAY
RTT DESKTOP TEST SET– INSTRUCTION MANUAL
67
4.2
The 239 Motor Management Relay
4.2.1
Overview
The 239 Relay has 3-phase current inputs but no voltage inputs feature. The 239 Relay
provides 2 programmable and 3 dedicated switch inputs designed for Dry contact
connection only, and 4 Form-C output relays. The 239 Relay monitors up to 3 RTD inputs,
each RTD being field programmable as a 3-wire type of 100 Platinum, 100 Nickel and 120
Nickel.
All features of RTT, other than VT, can be applied to the 239 Relay. However there are 5
unused input terminal wires, and a modification is required to the cable to fit the 239
terminals.
Modification of the Product Cable
For the wires related to contact inputs/outputs and RTDs (18 in total), cut the lugs off the
wire, and strip the wires to make them fit the 239 terminals.
The lugs to be cut are: R1+, R1-, R1C, R2+, R2-, R2C, R3+, R3-, R3C, DOC, DO2, DO1, DIC, DI5,
DI4, DI3, DI2 and DI1.
Unused Wires
For the unused wires (5 in total), it is recommended that user tape the lugs to ensure
isolation of the contacts so that no problems are caused by wires touching.
The unused wires are: DI8, DI7, DI6, V+, and V-.