Harsco Industrial P-K THERMIFIC N700 Installation & Owners Manual page 22

Correct Listed
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3.5.5.5 Sealed Combustion Inlet Damper and Control Panel (optional)
The inlet damper assembly and control panel prevents the flow of cold air through the boiler during the
off cycle and helps prevent freeze up. These two items are optional in all installations.
The damper must be field installed into a section of horizontal or vertical inlet ductwork. Orient the
damper such that the flow arrow points towards the boiler.
Field Wiring to Control Panel
The auxiliary control panel controls the inlet damper (if used). The auxiliary control panel does not have
to be mounted on or near the boiler. It can be remotely mounted.
Use minimum 16GA MTW wire for all field wiring. See Section 6.1 for the logic and wiring diagrams for
this auxiliary control panel and the sealed combustion boilers.
There are five (5) field run wires between the boiler and its associated auxiliary control panel; three (3)
for main power supply and two (2) for boiler interconnect.
1. The boiler and the damper must be connected to the same power supply.
2. Remove the blue jumper wire in the terminal block on the boiler before connecting the wires from the
auxiliary control panel to the boiler.
There are also five (5) field run wires between the auxiliary control panel and the inlet damper assembly;
three (3) to the damper actuator and two (2) to the limit switch.
1.Terminals for the damper actuator:
DO = Damper Open (Clockwise)
DC = Damper Closed (Counter clockwise)
DN = Neutral/Common
2. Terminals for the limit (end) switch
SI = N.O. (Normally Open)
S2 = Common
Incorrect
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(too restrictive)
P-K THERMIFIC
22
®
Gas-Fired Boiler