Tjernlund RT1500 Rooftop Draft Inducer 8504160 Rev 12/09 - Manuel (Page 10)

9
RT750 / RT1500 - PSA-1 FAN PROVING SWITCH ADJUSTMENT (SKIP IF INSTALLING RT750H / RT1500H)
1. Drill an appliance draft sampling hole in the vent riser after each draft diverter or between the flue outlet and the draft hood / baro-
metric draft control of each appliance. For most oil burners sample over-fire draft. Connect draft gauge to sampling hole, (See
Diagram N, Page 7).
2. For installations with a barometric draft control: Adjust weight on draft control to minimum or most responsive position (Less Draft).
3. WARNING: This step requires that the wires connected to the PSA-1 Fan Prover terminals be temporarily removed and
jumpered together. Disconnect power before proceeding.
Remove power source and connect leads attached to the C (common) and N/O (normally open) terminals of the PSA-1 together.
Attach a continuity tester to the C and N/O terminals of the PSA-1 Switch. Turn the PSA-1 adjustment screw counter clockwise until it
seats against the stop. The PSA-1 must be reconnected to the interlocked heaters(s) per the appropriate wiring diagram 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. If installing this product in conjunction with a
Tjernlund Products UC1 interlock control the number 9 dip switch must be positioned in the up/’on’ position.
Close all access doors and openings to the mechanical room that would typically be closed during heating equipment operation. Fire
all other heating equipment not connected to this vent system and operate exhaust fans or air consuming devices within the facility
that could affect the air pressure of the mechanical room.
4. Activate Rooftop Inducer and adjust balancing baffle(s) or speed control so that (-0.08" W.C. or -20 Pa) is read at the appliance
draft sampling position(s) referenced in Step 1. The PSA-1 switch contacts should close. If switch contacts do not close move
pressure sampling probe closer to the Inducer. Do not move sampling probe between manual damper and Inducer inlet.
5. Activate burner(s) at full capacity. Gradually adjust balancing baffle(s) or speed control to maintain a slight negative draft
(-0.02" to -0.05" W.C. or -5 to -12.5 Pa) at the heater’s 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 balancing baffle(s) or speed control are adjusted so that a slight negative
draft (-0.02" to -0.05" W.C or -5 to -12.5 PA) is measured at draft sampling location(s). Individual appliance vent connections may
require balancing baffles to evenly regulate draft.
7. Adjust balancing baffle(s) or speed control 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.
GND
CONTROL OPTION 3 CONTROL OPTION 4
HEATING APPLIANCE INTERLOCK USING UC1 HEATING APPLIANCE INTERLOCK USING UCRT
(WHITE)
(GREEN / BARE COPPER)
L1
N
TO INDUCER GROUND SCREW
TO INDUCER WHITE LEAD
TO INDUCER BLACK LEAD
TO INDUCER RED LEAD
N
L
N
M
MTR
P2
P1
CONTROL
TJERNLUND UC1
INTERLOCK OPTIONS
INSTRUCTIONS FOR
SEE UC1
(BLACK)
PSA-1
TJERNLUND
GND
(WHITE)
(GREEN / BARE COPPER)
L1
N
TO INDUCER GROUND SCREW
TO INDUCER WHITE LEAD
TO INDUCER BLACK LEAD
RED LEAD
N
L
CONTROL
TJERNLUND UCRT
INTERLOCK OPTIONS
INSTRUCTIONS FOR
SEE UCRT
(BLACK)
OFF
P2
P1
PSA-1
TJERNLUND
120 VAC 120 VAC
TO INDUCER
N
M
MTR
ON
LOW
ON
HIGH
SPEED
CONTROL
5 VDC BOARD-GENERATED POWER.
120 VAC
LEGEND
DO NOT SUPPLY POWER!
CONTROL OPTION 3
HEATING APPLIANCE INTERLOCK
USING OPTIONAL UC1 CONTROL
CONTROL OPTION 4
HEATING APPLIANCE INTERLOCK
USING OPTIONAL UCRT CONTROL