ICM Controls ICM251 Installation Guide

High Power, On Delay

Off Delay Fan Control for HVAC Systems

ICM 251

POST PURGE TIMERS

• ON delay lets air reach proper level prior to energizing fan

• OFF delay purges ducts of residual air to increase efficiency

CTVR

SPECIFICATIONS

Input

• Voltage: 18-30 VAC

• Frequency: 50-60 Hz

Output Ratings

• Relay Contacts

– N.O.: 20 amps @ 240 VAC

– N.C.: 10 amps @ 240 VAC

Time Delays (Adjustable Only)

• ON Delay: 1-180 seconds

• OFF Delay: 12-390 seconds

INSTALLATION

1. Disconnect power.

2. Connect terminals as shown in the wiring diagram below.

3. Select desired delay on make and delay on break periods.

4. Reapply power, check operation.

MODE OF OPERATION

Power must be applied at all times. Upon closure of the initiate switch the delay on make period begins. Once complete, the load is energized and remains energized as long as the initiate switch is closed. When the initiate switch opens, the delay on break period begins. Once complete, the load is de-energized and all time delays reset. If the initiate switch recloses during the delay on break period, the load remains energized and the delay on break period is reset.

Removal of the input power resets all timing functions. Should the initiate switch open during the delay on make period, the delay on make period is reset to zero.

Limit Switch: Continuous ON when opened.

If the initiate switch is open when the limit switch closes, the delay on break period times out and the load is de-energized.

WIRING DIAGRAM

C

Untimed Load

G C R

L

COM

SF

24

VAC

SS

PF

Input

120-240 VAC

PS

Initiate

Switch

Limit

Switch

R

ICM CONTROLS www.icmcontrols.com

7313 William Barry Blvd.

North Syracuse, NY 13212

800.365.5525

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