Honeywell Home Static Pressure Control (SPC)
Application
The Honeywell Home Static Pressure Control (SPC) is an adjustable, single-pole double-throw differential pressure switch. It is designed to regulate a floating-type modulating damper for bypass zone applications. Compatible dampers include the MARD or the ML6161 Actuator (90-second operation). The SPC features contacts rated at 125 VA.
[Diagram showing SPC dimensions, with overall height of 5 inches (127 mm) and width of 4-1/16 inches (103 mm)]
[Diagram illustrating the correct mounting orientation for the SPC with the adjustment screw on top.]
Installation
Selecting the Mounting Location
- Locate the SPC in proximity to the supply air ductwork.
- Ensure the SPC is oriented with the adjustment screw positioned at the top.
- Utilize the provided bracket and hardware for mounting.
Mounting the SPC
- Mount the SPC in an upright position near the supply ductwork.
- Install one threaded barb fitting into the lower pressure port.
- Attach the supplied tubing to the installed barb fitting.
- Drill a 1/2 inch hole into the ductwork.
- Insert the supplied surface mount duct fitting into the drilled hole.
- Seal the fitting with a small amount of silicone sealant.
- Secure the fitting using the two supplied self-tapping screws.
- Connect the opposite end of the tubing to the barbed end of the duct fitting.
[Diagram showing a threaded barb fitting being installed into the lower pressure port of the SPC.]
Wiring
Wire the SPC to the damper and a 24 Vac, 40 VA transformer (not supplied) as depicted in Figures 4 and 5.
[Wiring diagram showing the SPC connected to an ML6161 Actuator for a bypass application. Connections include COM, CCW (CLOSE), CW (OPEN) on the actuator and C, NC, NO terminals on the SPC, powered by a Model PMT-40 24 Vac transformer.]
[Wiring diagram showing the SPC connected to a MARD damper for a bypass application. Connections include COM/M1, CL/M6, OP/M4 on the MARD damper and C, NC, NO terminals on the SPC, powered by a Model PMT-40 24 Vac transformer.]
Settings
The SPC is adjustable from 0.1 in.wc to 4.0 in.wc, featuring a 10-15 percent null range. The factory default setting is 0.1 in.wc. To adjust the setting:
- Remove the hexagonal screw cap located at the top of the indicator.
- Use a screwdriver to turn the adjusting screw. The top of the adjusting screw serves as the indicator.
To increase the pressure setting, turn the screw clockwise (down). To decrease the pressure setting, turn the screw counter-clockwise (up).
[Diagram illustrating the adjustment mechanism of the SPC, showing the range scale from 0.1 to 4 in.wc (13 to 102 mm.wc) and indicating the adjustment screw.]
Checkout
Perform the following checks to ensure proper operation:
- Initiate calls for all zones and verify that the bypass damper is fully closed.
- Then, ensure only the smallest zone is calling and verify that the bypass damper opens.
Troubleshooting
If the SPC does not operate as expected during the checkout procedure, consult Table 1.
| Problem | Possible Trouble | Solution |
|---|---|---|
| SPC does not operate the damper. | Problem with the tubing. | Verify that the tubing is not kinked or plugged. |
| Wired incorrectly. | Verify the wiring connections. | |
| Bypass damper closes as zones are satisfied. | Incorrectly wired damper. | Verify that the N.C. (Normally Closed) and N.O. (Normally Open) terminals are correctly wired to the damper. |
| Damper does not open enough when the smallest damper is the only one calling. | SPC is set too high. | Decrease the pressure setting by turning the adjustment screw up (counterclockwise). |
| Damper does not close fully when all zones are calling. | SPC set too low. | Increase the pressure setting by turning the screw down (clockwise). |
Resideo Technologies, Inc.
1985 Douglas Drive North, Golden Valley, MN 55422
1-800-468-1502
www.resideo.com
Printed in United States
© 2021 Resideo Technologies, Inc. All rights reserved.
The Honeywell Home trademark is used under license from Honeywell International, Inc. This product is manufactured by Resideo Technologies, Inc. and its affiliates.
