Chromalox Big Red Book

Controls

LM-2 Solid State Relay Driver for SSR Series • Easily Mounted Directly to Terminals • Single & 3-Phase 2-Leg Configurations • Accepts 4-20mA Control Signal • Power Supply not Required • For Use with Chromalox SSR Series Controllers

Description The LM-2 (0135-28144) module accepts a 4 - 20 mA control signal and converts it to a 4.5 - 32 VDC time proportional control signal. Power supply is not required. The LM-2 is pow- ered by the 4 - 20 mA loop. The LM-2 Module supports single and three-phase 2-leg power control configurations. The LM-2 module mounts directly to the input terminals labeled A2(-) and A1(+) of the solid state relay. Screw terminals are provided on the LM-2 module for the 4 - 20 mA control signal. The solid state relay's load is connected to terminals L1 and T1. Once the connections are made the LM-2 module and solid state relays provide a time proportional zero-fired control signal to the load.

Specifications Input.................................................4 - 20 mA Time Base........................... 3 Cycle Resolution Compliance Voltage Requirement.....6.4 VDC (320 ohms @ 20 mA) Span & Linearity....................... Better than 2% Ambient Temperature...................... 32 - 104˚F Dimensions................ 1.25"W x 1.75"L x .75"D

Stock PCN Chart Model

PCN

0135-28144

341260

4-20mA Terminal Connections

Single Phase Power Control Wiring

OPTIONAL FUSE

SSR1

AC INPUT VOLTAGE

L1

A1 + A2 -

(-)

Single-Leg Harness Jumper Connection

4-20 mA Control Signal Screw Terminals

L O A D

SSR

LM-2

(+)

T1

SSR-1

LM-2 Module

CONTACTOR COIL

Three Phase Power Control Wiring

OPTIONAL FUSE

Heat Sink

SSR2 Module

L1

L1

A1 + A2 -

(-)

4-20 mA Control Signal Screw Terminals

4-20mA Terminal Connections

LM-2

SSR

(+)

T1

Harness Part # 0023-70178

LOAD

L2

L1

A1 + A2 -

Blk

LOAD

SCR COMPONENTS

SSR

LOAD

T1

Red

Fan

L3

SSR-2

CONTACTOR COIL

Two-Leg Harness Jumper Connection

LM-2 Module

H-97