Product Overview
Specifications:
Pressure Set point Range - .1" to 4" W.C.
Sensing Element - Reevecote diaphragm
Electrical - Two Field Connections (24VAC)
Pressure - Barbed for 3/8" OD plastic tube
Case - Cast Aluminum & 3/4" conduit opening
Mounting - The Pressure Switch should be oriented 
so that the adjustment stem is pointing 
vertically up. (If necessary, loosen the mounting 
bolt and adjust the pressure switch.)
How the Bypass System Works:
As the individual zone dampers open and close, the 
system static pressure will rise and fall. In order to 
maintain proper air flow and static pressure through 
the HVAC system, a bypass system incorporating a 
reversible  type  motorized  damper  and  a  static 
pressure control is used. The static pressure control 
monitors  the  static  pressure  and  energizes  the 
damper  motor  open  or  closed,  to  maintain  the 
desired   airflow and static pressure.   The damper 
will  modulate  to  hold  the  desired  Static  Pressure 
Set-Point.
Description of Bypass Dampers:
ROUND BYPASS DAMPERS are fabricated from 20, 
22,  &  24  gauge  galvanized  steel.  Shells  are 
furnished  with one  straight  end  and  one  crimped 
end  with  rolled-in  stiffening  beads  for  rigidity. 
RECTANGULAR BYPASS DAMPERS are fabricated  
from  mill  finished,  extruded  14  gauge  aluminum, 
parallel blade design.
All round bypass dampers are equipped with low 
leakage blade seals.
*Shell length=Diameter + 0.75
*Medium duty - up to 1”W.C.
*Heavy duty - up to 2”W.C.
*Specify round - 8”, 10” , 12”, 14”, 16”,18”, 20”
*Specify rectangular - 12x8,12x10,12x12,20x8
 20x10,20x12
*Custom  sizes  are  available,  call  for 
details.
Description of Static Pressure Control:
The static pressure control is a heavy duty air pressure 
switch, with a sensitive diaphragm.
An  integrated  micro-switch  and  a  visual  ON/OFF 
indicator  are  also  included.  The  spring  adjustable 
switch  has  dual  scales  calibrated  in  millimeters  and 
inches of water column for easy setup. 
The Electronic Bypass design includes the Model 
MA-AC1 Motor Actuator with Open & Closed LED 
indicators  for  Medium  Duty  applications,  and  a 
rugged  LM-24  Belimo  motor  for  Heavy  Duty 
applications!
Both models are designed to be easy to install and 
service in the field.
TM
Forced Air Zone Controls
Model EBD
Electronic By-Pass Damper
SUBMITTAL SHEET
Separate 24 vac 
20 va Transformer
Or Connect to M1/M2
on any EWC Controls
Zone control module.
“EBD” ELECTRONIC BYPASS MOTOR 
AND STATIC PRESSURE CONTROL 
DAMPER ASSEMBLY
Field Wiring =
Factory Wiring =
Note: Remove cover off of diaphragm to field wire.
NC
NO
C
WIRE 
NUT
1
4
6
MA-AC1
MOTOR 
PS4
PRESSURE SWITCH
385 Hwy. 33 
Englishtown, NJ 07726
Ph: 800-446-3110 
Fx: 732-446-5362
P/N 090377A0061 REV. I 04.08.10
CONTROLS INC.
E
W
Excellence Without Compromis
e
Copyright © EWC Controls Inc., 2000 All Rights Reserved
SUBMITTAL FORM
SUBMITTED BY:
JOB:
ARCHITECT:
ENGINEER:
CONTRACTOR:
LOCATION:


