TrueZONE® Bypass (CPRD)
INSTALLATION INSTRUCTIONS
The TrueZONE® Bypass constant pressure regulating damper (CPRD) is a round static pressure relief damper. It is used in forced-air bypass applications to relieve excess static pressure when some of the zone dampers are closed. The damper is installed in a duct that delivers air to the return or a dump zone. The damper automatically opens and closes to maintain a desired static pressure.
The CPRD uses a calibrated spring to regulate the bypass air accurately when any number or combination of zones is calling. Conventional, weighted arm, bypass dampers may operate properly when one zone is calling; however, when different combinations of zones are calling, they bypass too much or too little. This can cause callbacks when homeowners complain of air noise.
1.Size the bypass damper by subtracting the cfm of the smallest zone from the cfm of the system.
2.Consult Table 1 to determine the CPRD to use.
3.Example:
Bypass CFM = Total System CFM - Smallest Zone CFM
Construction:
Galvanized steel, see Table 2
Temperature Range:
Ambient: 0F–165F (-17C–73C)
Storage: 30F–150F (-1C– 65C)
Table 1. Damper Sizing
Bypass |
Replacement |
|
Damper |
Regulator |
Maximum Airflow |
|
|
|
CPRD8 |
CPR8 |
600 CFM |
|
|
|
CPRD10 |
CPR10 |
1000 CFM |
|
|
|
CPRD12 |
CPR12 |
1400 CFM |
|
|
|
CPRD14 |
CPR14 |
1700 CFM |
|
|
|
Regulator
D C
E
A
Damper
B
M34207
Table 2. CPRD Dimensions.
|
|
A |
|
B |
|
C |
|
D |
|
E |
|
|||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Model |
in |
|
mm |
in |
|
mm |
in |
|
mm |
in |
|
mm |
in |
|
mm |
Gauge |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
CPRD8 |
8 |
|
203.2 |
9.65 |
|
245 |
1.50 |
|
38 |
11.54 |
|
292.84 |
4.65 |
|
118 |
26 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
CPRD10 |
10 |
|
254 |
11.42 |
|
290 |
1.50 |
|
38 |
13.50 |
|
343 |
4.65 |
|
118 |
26 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
CPRD12 |
12 |
|
305 |
13.18 |
|
235 |
1.50 |
|
38 |
15.47 |
|
392.84 |
4.65 |
|
118 |
24 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
CPRD14 |
14 |
|
355 |
14.96 |
|
380 |
1.50 |
|
38 |
17.36 |
|
441 |
4.65 |
|
118 |
22 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
69-2770EFS-03
TRUEZONE® BYPASS (CPRD)
Install the CPRD onto a starting collar or in duct that loops from supply to return. The supply side take-off must be before any zone dampers. It is best to install the return side of this loop as far a practical from the air handler.
The CPRD can be mounted in vertical or horizontal ductwork, or at any angle. The damper may also be rotated to be installed with the regulator on either side, top or at any angle between.
Secure the damper to sheet metal ductwork with screws or to flex-duct with tape. If ducting with flex-duct, the outer layer of plastic can be taped to the damper mounting flange to fully insulate the damper.
Alternatively, the CPRD can dump air from the supply to a non-critical temperature area such as a hallway, basement, or false ceiling.
1.Align the regulator with the "D" shaft on the damper (see Fig. 1).
2.Slide the regulator onto the "D" shaft and push down while turning counterclockwise until it snaps into place (see Fig. 2).
M34208 |
Fig. 1.
M34209
Fig. 2.
The CPRD is factory set to open at approximately .5"WC." This setting is satisfactory for most installations. Some systems have higher static pressure.Test this by:
1.Make all zones call fan, heat, or cool; whichever has the highest CFM.
2.Verify that the damper position indicator points to closed.
3.If it does not point to closed:
•Flip the adjustment crank out (see Fig. 3)
•Push down on the adjustment crank with gentle pressure. Caution: Do not rotate the adjustment crank without first pushing it down
•Turn the adjustment crank clockwise until the indicator points to closed
•When done, flip the adjustment crank back into the locked position
4.Make only the smallest zone call for fan, heat, or cool.
5.Verify that the airflow into that zone is not objectionable. If it is, then set the regulator to a lower pressure.
If you need to remove the regulator from the damper, do so by pressing the red release button. See Fig. 4. It is easier to remove the regulator after turning the pressure down to a lower setting.
Automation and Control Solutions
M34210 |
Fig. 3.
PRESSURE SETTING |
DAMPER POSITION |
INDICATOR |
INDICATOR |
|
ADJUSTMENT |
RELEASE |
CRANK |
BUTTON (RED) |
M34211 |
Fig. 4. CPRD regulator
Honeywell International Inc. 1985 Douglas Drive North Golden Valley, MN 55422 customer.honeywell.com
® U.S. Registered Trademark
© 2012 Honeywell International Inc.
69-2770EFS—03 M.S. Rev. 12-12
Printed in United States
Dérivation TrueZONE® (CPRD)
NOTICE D’INSTALLATION
Le registre de régulation de pression constante (CPRD) de dérivation TrueZONE® est un registre de pression statique rond. Il est utilisé dans les applications de dérivation à air pulsé pour limiter la pression statique en excès lorsque certains registres de zone sont fermés. Le registre s'installe dans une gaine fournissant de l'air à la zone de retour ou d'évacuation. Le registre s'ouvre et se ferme automatiquement pour maintenir la pression statique désirée.
Le CPRD utilise un ressort étalonné pour réguler avec précision l'air de dérivation en cas d'appel de diverses zones ou combinaisons de zones. Les registres de dérivation à bras lesté conventionnels peuvent fonctionner adéquatement en cas d'appel d'une seule zone; toutefois, lorsque diverses combinaisons de zones lancent un appel, la dérivation est insuffisante ou excessive. Ceci peut causer des retours de produits lorsque les propriétaires se plaignent du bruit causé par l'air.
1.Dimensionner le registre de dérivation en soustrayant la superficie de la zone la plus petite de la capacité du système.
2.Consulter le Tableau 1 pour déterminer le CPRD à utiliser.
3.Exemple : Superficie dérivation = Capacité totale du système - Superficie de la zone la plus petite
Construction : Acier galvanisé, voir le Tableau 2
Plage de température :
Ambiante : 0 °F-165 °F (-17 °C-73 °C)
Stockage : 30 °F-150 °F (-1 °C-65 °C)
Tableau 1. Dimensionnement du registre.
Registre de |
Régulateur de |
Débit d'air |
dérivation |
rechange |
maximum |
|
|
|
CPRD8 |
CPR8 |
600 CFM |
|
|
|
CPRD10 |
CPR10 |
1000 CFM |
|
|
|
CPRD12 |
CPR12 |
1200 CFM |
|
|
|
CPRD14 |
CPR14 |
1400 CFM |
|
|
|
|
D |
C |
Régulateur |
E |
|
|
|
A |
|
Registre |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
B |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
MF34207 |
|||
|
|
|
|
|
|
|
Tableau 2. Dimensions du CPRD |
|
|
|
|
|
|
|
|
|||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|||||
|
|
A |
|
B |
|
C |
|
D |
|
|
E |
|
|
|
|
|||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Modèle |
po |
|
mm |
po |
|
mm |
po |
|
mm |
po |
|
mm |
|
po |
|
|
mm |
|
Calibre |
|||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
CPRD8 |
8 |
|
203,2 |
9,65 |
|
245 |
1,50 |
|
38 |
11,54 |
|
292,84 |
4,65 |
|
118 |
|
26 |
|
||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
CPRD10 |
10 |
|
254 |
11,42 |
|
290 |
1,50 |
|
38 |
13,50 |
|
343 |
4,65 |
|
118 |
|
26 |
|
||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
CPRD12 |
12 |
|
305 |
13,18 |
|
235 |
1,50 |
|
38 |
15,47 |
|
392,84 |
4,65 |
|
118 |
|
24 |
|
||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
CPRD14 |
14 |
|
355 |
14,96 |
|
380 |
1,50 |
|
38 |
17,36 |
|
441 |
4,65 |
|
118 |
|
22 |
|
||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|