User Guide

Figure-13 Attachment of Conduit Box to Threaded Adaptor.

Note:

As shown in Figure-11 , the hole in the cover plate of the actuator conduit housing is

sized to accept both British standard M20 (20 mm) conduit connectors and 20 mm-to-PG16

adaptors for use with DIN PG16 connectors. (Follow the steps for installing the conduit box

to the actuator.)

Linkage Assembly Damper

Note:

Each actuator in the MPR-5X3X series is provided with a factory-installed damper

linkage. No separately-ordered linkage is required.

Caution:

• Do not twist or exert any force on the actuator housing during installation. Either turn

the base by hand or, if necessary, use a 1-5/8" open-ended wrench (TOOL-37) on the

flats provided on the actuator base, or on the valve body mounting nut. (Refer to

Figure-4 )

1. Determine the best mounting position for the actuator as follows:

a. Determine, from the system requirements, if the damper should spring-return to the

open position (Figure-14 ) or closed position (Figure-15 ) whenever power is lost

to the actuator. An actuator is normally linked so as to retract (spring-return) to the

damper’s fully open position (heat position).

Figure-14 Dampers Open When Actuator Retracts

(Spring-Returns Open on Power Loss).

Conduit Lock Nut

Spring returns open

on loss of power

Open

ExtendRetract

Damper Shaft