Crathco WD Installation Manual

Damper Frame

⁄2 in.-14 NPSM

Damper Blade

Damper Tie Bar

Spring Rod

Document Number 452723

Field Installation Instructions for End Switch Kit #851038

These instructions apply to the field installation of end switch kits on Greenheck model WD Backdraft Dampers. These end switch kits can be used in conjunction with MP-100, MP-200, and MP-300 Series actuators.

End switches are typically wired to a fan and/or to a light serving as an open/not open indicator. When the damper is powered open, one of the damper blades makes contact with the spring rod of the end switch which in turn makes a connection allowing power to flow to the fan and/or light. This set up would be used when it is desirable to ensure that the damper is fully open before the fan starts.

When the end switch is utilized to delay start up of Vari-Green® or other ECM fan motors (electronically commutated motor), a magnetic fan starter is required.

Instructions:

1. Position end switch such that the back side of damper blade trips the spring rod.

2. Mount end switch bracket to damper frame or ductwork using #10 x 1⁄2 in. self-drilling sheet metal screws

For use on WD series Dampers

Part # Qty. Description

1 1 End switch mounting bracket

Damper Tie Bar

2 1 End switch

3 2 #6-32NC x 1½ in. machine screws with

4 2 #10 x ½ in. self-drilling sheet metal

UL/CSA Rating L67 15 Amps: 125, 250, or 480 VAC

0.25 Amps: 250 VDC

0.50 Amps: 125 VDC

nuts (packaged in end switch housing)

screws

End Switch Kit

Damper Frame

⁄2 in.-14 NPSM

Fan or

Light

N.C.

End

Switch

Note: Some actuators are multi-tap, use correct connections per actuator wiring diagram.

Common

N.O.

Green

Damper Actuator

Alternative wiring diagram

Wiring Illustration

Damper Blade

Damper Tie Bar

Spring Rod

End Switch Installation On

WD-100 Series Dampers

Damper Frame

Spring Rod

End Switch Installation On

⁄2 in.-14 NPSM

WD-200 & 300 Series Dampers

#452723 End Switch Rev 6 June 2015

Damper Blade