KMC Controls MEP-5233 User Manual

Direct-Coupled Replacement Damper Actuators
for Residential Zone Dampers

MEP–5223 and MEP-5233

Installation Guide

Mounting

The MEP-5223 and MEP-5233 are replacement damper actuators designed for residential zone dampers. The
MEP-5223 replaces series B and C actuators on round dampers with a fully closed blade angle of 45 degrees. The
MEP-5233 replaces series B and C actuators on rectangular dampers with a fully closed blade angle of 90
degrees. The series B and C dampers use crank-arms to turn the damper shafts. The MEP units employ a direct­drive gear and mounting hub assembly to turn the damper shaft, eliminating the need for crankarm assemblies.

CAUTION: Operation problems will occur if the wrong actuator is applied to the wrong style damper. Use
the MEP-5223 actuator ONLY on round dampers and the MEP-5233 actuator ONLY on rectangular dampers.

1. Turn power off.

2. Disconnect 24 VAC wiring to damper actuator.

3. Remove the old actuator or actuator assembly from the damper shaft and damper.

NOTE: After the actuator assembly is removed the damper shaft and blade should move freely. If the unit
sticks or binds, repairs should be made before installing the new actuator.

4. Using a marker place a line on the end of the
damper shaft to indicate the damper blade
position.

5. Slide the new actuator unit directly on to the
standard 1/2" diameter damper shaft.

6. Use the non-rotation bracket (provided) and 2
screws, to align the bottom of the actuator to
the mounting plate. Most replacements will
require 2 new holes to secure the bracket to
the mounting plate.

7. Using the gear disengagement button, rotate
the mounting hub counter clockwise to the fully
open position.

10. Turn the shaft to ensure that the damper blade
is in the fully open position.

11. Using a 5/32" hex/key wrench, firmly tighten
the set screw to secure the damper shaft and the
mounting hub.

Wiring

1. Remove access cover to expose terminal block.

2. Route wires through the grommets in the cover.

3. Provide strain relief to prevent wires from pulling or
snagging.

4. Connect stripped wires to appropriate terminals:

CW (clockwise to close)

COM (common)

CCW (counterclockwise to open)

5. Replace access cover.

6. Install or reposition any insulation (check local codes).
In areas where excessive condensation may occur,
carefully insulate over the actuator assembly. Make sure
the insulation does not interfere with actuator operation.

Adjustments

Once the unit is installed check dampers and verify
operation. When 24 VAC is applied between common and
open the damper should fully open in approximately 15
seconds (18 seconds in 50 hz applications).

If the damper jams or stalls it will not damage the damper
or motor. These problems are usually the result of twisting
or bending of the damper body during installation.
Straightening the damper body usually fixes these
problems.

If it become necessary to force a damper open, press the
gear disengagement button and simultaneously turn the
mounting hub. Release the button to hold the damper in
the new position.

Maintenance

No routine maintenance is required.

The motors are permanently lubricated and all internal
gear-train components are oil-impregnated. Careful
installation will ensure long term reliability and
performance.

KMC Controls

19476 Industrial Drive

New Paris, IN 46553

TEL: [phone]

www.kmccontrols.com

026-019-03