Sterling SDFI, Installation And Maintenance Instructions Manual

Page: 6 / 36

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SECTION V - UNIT START-UP GENERAL
Make sure all doors and service panels have been
closed or replaced.
Turn main disconnect switch off. Check the incoming
line voltage to match unit nameplate rating. If voltage
is over
±
10% of nameplate rating or phase voltage
unbalance is over 2%, notify contractor or power
company.
Turn main disconnect switch on. Turn Fan-Off-On
switch to On position. Damper opens (if applicable).
Blower fan turns on.
Turn Fan-Off-On switch to Off position. Check supply
blower for proper rotation.
NOTE: To change rotation of the blower, simply
interchange any two (2) of the line leads of the
motor starter for three (3) phase motors. On single
phase motors refer to motor nameplate.
Turn Fan-Off-On switch to On position. Check for
proper blower rpm. Check that all motor amp draws do
not exceed nameplate ratings and overloads are set to
motor nameplate amps.
Check all dampers for proper operation, and linkage
does not bind, see “Sequence of Operation”.
Make sure all manual gas valves are closed.
Turn Fan and Heat Off-On switches to On position.
Blower fan will run and burner will fail to light.
Reset flame relay.
Turn Fan and Heat Off-On switches to Off position.
Unit Start-Up: Systems with Pilot
NOTE: To adjust gas pressure on supply lines
where a regulator has been installed (to reduce the
inlet pressure to 5 PSIG or less), remove dust cap
of main gas regulator and turn adjusting screw
clockwise to increase pressure or counter-
clockwise to decrease pressure.
Connect test instrument to pilot flame test jack located
on flame safeguard relay.
Set all thermostats to call for heat. Set inlet ductstat (if
applicable) above outside air temperature.
Open pilot and first main gas shut-off valves slowly.
Last main gas shut-off valve before burner must
remain closed at this time. Reset high-low gas pres-
sure switches (if applicable). Check pilot and main gas
lines for leaks.
Turn Fan and Heat-Off-On switches to On position.
Blower fan will run.
Unit will run for 7 seconds before ignition trial, if all
safety and limits are made.
NOTE: 3 OR 4 TRIALS MAY BE NEEDED TO
PURGE AIR FROM PILOT LINE. IF BURNER HAS
MAIN FLAME ROD OR SCANNER, YOU MAY NEED
TO DISABLE TIMER CIRCUIT.
11. Check burner for proper location and alignment.
12. Check that filters and accessories are installed correctly.
13. Check that vent lines have been run to atmosphere
on indoor units. Note that some units will use vent
limiters and vent lines are not required.
14. Check that all manual gas shut-off valves are closed.
15. When failure or malfunction of this heater creates
a hazard to other fuel burning equipment, (e.g.
when the heater provides make-up air to a boiler
room), the heater is to be interlocked to open inlet
air dampers or other such devices.
16. If inlet duct is attached to the heater, a purge
timer must be provided and set to purge 4
times the inlet duct volume.
Purge time in seconds = 4 x L x W x H x 60
SCFM
L = duct length in feet, W = duct width in feet,
H = duct height in feet, SCFM = rating plate air
throughput.
Refer to the electrical schematic for the proper
circuit placement. Purge timer P/N 65.0711.00.