MACH® Gas-Fired Boiler
Page 17
Table of Required Stainless Steel Vent Adapters and Category II Motorized Dampers
The normally-
closed motorized damper operates on 120 VAC and features an end limit switch wired into the boiler’s
external interlock circuit. Upon a call for heat, the boiler’s damper relay will energize and drive the damper open.
Once the damper reaches the fully-open position, the end limit switch makes contact and closes the external interlock
circuit allowing the boiler to fire. The diagram below shows the wiring necessary to install the normally-closed
motorized damper.
Boiler Size
Nominal
Stack Size
Stainless Vent
Adapter
Normally-Closed
Motorized Damper
A
B
C
D
C1500GG -
C2000GG
10"
2630000226
1004906945
10” 10” 13” 3.38”
Use caution if installing a barometric damper in the exhaust vent. The
vent pressure
must be negative
(Category II) at all times to prevent leakage of harmful flue
gases into the room. Leakage of flue gases can cause serious injury or death.