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GENERAL DESCRIPTION
The model PRD pressure regulating damper is a single blade rectangular barometric
damper with a counter balanced weighted arm. The PRD is an economical way of
bypassing excess air when zone dampers close. Damper adjustment is done by
moving the weight up and down the arm and by off-setting the arm. See Page 2 for
details.
The PRD is installed in the By-Pass ductwork to regulate the excess air pressure. The
damper can be mounted to relieve the pressure by returning the air back to the return
air duct (See Figure 1) or by dumping it into a non-critical conditioned area.
The PRD is an ideal By-Pass solution for any Constant Speed or Variable Speed
system up to 5 ton capacity.
Return air
FIGURE 1
Model numbers, sizes available and amount of CFM bypass
*By-Pass CFM is determined at 0.3" w.c. Friction per 100' of ductwork
TB-224
EWC Controls Inc. 385 Highway 33 Englishtown, NJ 07726 800-446-3110 FAX 732-446-5362
P/N 090375A0224
REV. H
Bypass Damper Assembl
6'
HVAC
UNIT
MODEL #
SIZE W x H BYPASS CFM*
PRD 12 x 8
PRD 12 x 10
PRD 12 x 12
PRD 20 x 8
PRD 20 x 10
PRD 20 x 12
©
Copyright
2006-2008 EWC Controls All Rights Reserved
TECHNICAL BULLETIN
Leave this bulletin on the job site for future reference!
PRD or PRD-RD
12" x 8"
1,000 CFM
12" x 10"
1,200 CFM
12" x 12"
1,400 CFM
20" x 8"
1,600 CFM
20" x 10"
2,000 CFM
20" x 12"
3,000 CFM
Model PRD
Barometric By-Pass Damper
y
E-Mail- info@ewccontrols.com
Supply air
1
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Table of Contents
Related Manuals for EWC Controls PRD
Summary of Contents for EWC Controls PRD
- Page 1 See Page 2 for details. The PRD is installed in the By-Pass ductwork to regulate the excess air pressure. The damper can be mounted to relieve the pressure by returning the air back to the return air duct (See Figure 1) or by dumping it into a non-critical conditioned area.
- Page 2 Position PRD door to open in the direction of your airflow by forcing it over the stop. Make the PRD connection on the return so that the bypass air has a minimum 6 feet of return duct before it enters the air handler, if space permits. If not do your best.
- Page 3 AIR FLOW IS IN DIRECTION INDICATED AIR FLOW IS IN DIRECTION INDICATED BY THE ARROW ABOVE BY THE ARROW ABOVE IDEAL LOCATION THUMB SCREWS WEIGHT FIGURE 2 EWC Controls Inc. 385 Highway 33 Englishtown, NJ 07726 800-446-3110 FAX 732-446-5362 E-Mail- info@ewccontrols.com...
- Page 4 7 - REFER TO PAGE 2 FOR SET-UP PROCEDURE. THUMB SCREW LOCKING-COLLAR DAMPER SHAFT HEX-ARM FIGURE 3 -- CUT AWAY VIEW OF ASSEMBLY FIGURE 4 -- CLOSE-UP VIEWS OF ASSEMBLY EWC Controls Inc. 385 Highway 33 Englishtown, NJ 07726 800-446-3110 FAX 732-446-5362 E-Mail- info@ewccontrols.com...
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