Patterson-Kelley P-K STORM ST-8000 Installation And Owner's Manual page 41

Motorized combustion air dampers must be powered from an external power supply other than the
appliance. The figure below shows a sample installation in which Relay C is user-selected to operate a
120VAC motorized air damper. Relay C is normally-open, so when the appliance is in standby, the
combustion air damper remains closed. Once a call for heat is received, Relay C closes the 120VAC
circuit (external power supply) which provides power to the damper motor, opening the damper.
the motorized damper is fully-open, its end limit switch completes the Air Damper Interlock circuit
(120VAC) which allows the appliance to proceed to ignition.
External power supplies are required for Relay A, Relay B, Relay
C, and Relay D. Because power is provided from an external
source, the power is still present when the appliance is turned off.
Check all voltage sources have been disconnected prior to
servicing. Failure to do so could result in electrocution, injury, or
N !
OTICE
Relay A, Relay B, Relay
C, and Relay D are
rated for a maximum
voltage of 120VAC and
a maximum current
capacity of 1/2 Amp.
Customer must supply
fusing for all current
connected to the relays.
Connecting a motorized
damper which exceeds
the voltage or current
capacity of the relay
could cause permanent
damage to the relay.
Revised: February 2, 2024
Released: February 2, 2024
death.
 Patterson-Kelley 2024
All Rights Reserved.
P-K Storm
Technical Service 1.877.728.5351
Note: The NURO
the user to allocate Relay A, B, or
C for use with a motorized
combustion air damper. The
figure above shows Relay C in
use for the motorized combustion
air damper. Depending on the
user-configuration, Relay A, Relay
FUSED
B, or Relay C can be selected to
operate the combustion air
damper.
2691000403 P-K Storm ST2500-ST8000
Installation and Owners Manual Rev G.docx
®
Gas Fired Boiler
Once
® control allows
Page 30