EWC Controls logo
Ph: 1-800-446-3110

Fx: 1-732-446-5362
EWC Controls, Inc.
385 Highway 33
Englishtown, NJ 07726
Motorized Rectangular Dampers
Old Fashioned Reliability With NEW State of the Art Technology
ND Damper
ND-RSD Damper
  • Heavy Duty Frame
  • Nylon Bushings for Quieter Operation
  • Revolutionary Motor with greater Reliability
  • LED’s to Show Damper Operation
  • Low Leakage
  • Simple 3-wire Hook-up
  • Easier Ordering
  • Motor is always mounted on second dimension specified
The ND series of Ultra-Zone dampers was designed with the installer and homeowner in mind. This damper is easy to install and easy to checkout. The LED display allows the installer to visually check the damper operation. With a sturdier frame, the damper installs in the duct much faster and easier and the nylon bushings insure quieter operation. This is a feature that homeowners will never hear about! Quieter operation and a longer life motor equals NO call backs.
The motor for the ND damper is driven by 17 in. lbs. of torque, possesses a manual gear release, 3 wire power open/power closed operation and fail-safe LED’s for quick diagnostic checks. The motor is UL listed and NEMA Class 2 certified. The easy access, quick connecting terminal block eliminates the need for wire nuts and allows for trouble free use.
The ND damper has a 97% leak proof rating. Overlapping blades and a strong positive off motor insures accurate control of all zones. The ND dampers combined with the Ultra-Zone zoning system provides the most comfortable and reliable system in the industry.
The ND is available in 8" x 6" thru 30" x 30" in even inch increments. The motor will be mounted on the second dimension when ordered. For example, a 16" x 8" damper will have the motor mounted on the 8" dimension, while an 8" x 16" will have the motor mounted on the 16" dimension. This will alleviate the confusion between side mount and bottom mount dampers.
For added flexibility, ND dampers can also be provided with a spring return style motor , Model ND-RSD.  The ND-RSD does not have LEDs.  Please specify the unpowered state of ND-RSD dampers as "normally closed" or "normally open" when ordering.
Notice: The MA-ND5 (power open/power close) motor actuator cannot be used to replace an existing MA-RSD (spring return) motor actuator, nor can an MA-RSD replace an MA-ND5.
3/8" hex shaft - no motor
Manual Quadrant - no motor
35 in/lbs 24 volt motor
Modulating Motor
15 Second Motor
End Switch
24V Spring Return
120V Spring Return
Duct Board Adapters
Duct Board Adapter
These brackets are used to mount ND and ND-RSD style dampers to fiberglass duct boards. The brackets are 1" thick. Add the number "5" to the part number for 1.5" thick duct board (EX: DBA-10-5).  Sizes range from 6" - 24" in 2" increments.