Tjernlund Auto-Draft FSAD & VSAD Series Inducers 8504090 Rev 11/00 - Manual (Page 18)

5. Activate burner(s) at full capacity. Gradually adjust common manifold manual damper or VFD to maintain a slight negative draft
(-0.02” W.C. or -5 Pa) at draft sampling location(s). Allow vent temperatures to reach steady state by referencing breaching
flue gas temperatures.
6 Once flue gas temperatures have stabilized, verify that common manifold manual damper or VFD are adjusted so that a slight neg-
ative draft (-0.02” W.C. or -5 Pa) is measured at draft sampling location(s). Individual appliance vent connections may require
balancing dampers to evenly regulate draft.
7. Adjust common manifold manual damper or VFD so that a slight positive draft (neutral to +0.01” W.C. or +2.5 Pa) is measured at
the appliance draft sampling location. Flue gases should just start to spill from the draft hood/draft diverter or barometric draft control.
8. Turn the PSA-1 Fan Prover Switch adjustment screw clockwise in 1/6-turn increments, waiting 2-3 seconds after each adjustment
until the micro-switch opens and no continuity is read.
9. Readjust the common manifold manual damper or VFD so that a negative draft (-0.02 to -0.05” W.C. or -5 to -12.5 Pa ) is
once again measured at the appliance draft sampling location. This readjustment must be enough to cause the PSA-1 Fan Prover
Switch to close. The PSA-1 may take a few moments to close after each adjustment.
10. Confirm Fan Prover Switch set point by adjusting common manifold manual damper or VFD so that a slight positive draft (neutral
to +0.01” W.C. or +2.5 Pa) is measured at the appliance draft sampling location. Flue gases should just start to spill from the
draft hood/draft diverter or barometric draft control and the Fan Prover Switch should open. Readjust the common manifold
manual damper or VFD so that a negative draft (-0.02 to -0.05” W.C. or -5 to -12.5 Pa) is once again measured at the appliance
draft sampling location. Verify that the PSA-1 Fan Prover Switch closes.
11. Interlock Fan Prover Switch with burner circuit per diagram(s) in wiring instructions and run entire heating/vent system through 3
cycles to verify proper burner light off and operation. Verify that each appliance lights off properly with all other appliances not firing.
VERTICAL TERMINATIONS: If barometric draft control(s) are excessively open, adjust weight so the draft control damper opens less
and repeat process starting with step # 3.
SIDEWALL TERMINATIONS: It is normal for the draft control damper to be close to wide open. This will allow the Auto-Draft® Venter
to respond to high wind loads.
The PSA-1 must be reconnected to the interlocked appliance(s) after completing these procedures. Failure to do so may
result in a hazardous condition such as an explosion, fire or carbon monoxide poisoning resulting in property damage,
personal injury or death.
SAFETY INTERLOCK TEST
1. Adjust the appliance thermostat(s) or aquastat(s) to call for heat.
2. Determine that the Auto-Draft® Venter operates before the gas valve or burner becomes energized.
3. With the appliance(s) and Auto-Draft® Venter operating, disrupt power to the Auto-Draft® Venter and determine that the appliance
gas valve(s) or burner motor(s) shut off.
Do not operate an appliance that does not shut off with the Auto-Draft® Venter disabled.
COMBUSTION AIR
Adequate combustion air is vital for proper combustion and for safe venting. Likewise, for proper venter performance, adequate com-
bustion air must be available to the appliance. Many installers assume adequate combustion air is present, especially in older struc-
tures. In some cases this is a false assumption, because many structures have been made "tight" due to weatherization. Size the
combustion air opening(s) into the equipment room as outlined in NFPA 31, 54 & 211. Tjernlund’s IN-FORCER
TM combustion air
intake systems provide a convenient, automated way to supply combustion air to the equipment room. When installing the Auto-
Draft® Venter it is not necessary to supply any more combustion air than normally required when conventional venting.
MAINTENANCE
Disconnect the power supply when making wiring connections or when working around the fan impeller and motor. Failure
to do so can result in electrical shock, personal injury, death or property damage.
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