LAARS Pennant PNCV - Install and Operating Manual - Manual (Page 31)

Low Temperature Pennant Page 31
necessary. The manifold gas pressure must be
2.5” W.C. (0.62kPa).
8. Complete the setup by checking the CO
2
at the
outlet of the unit. The CO
2
should be 8% for
natural gas, or 9.2% for propane.
9. After placing the appliance in operation, the
Burner Safety Shutoff Device must be tested.
To test:
(a) Close gas shutoff valve with burner
operating.
(b) The flame will go out and blower will
continue to run for the post purge cycle.
One additional attempt to light will follow.
Ignition will not occur as the gas is off. The
ignition control will lockout, and will have
to be reset before the unit will operate.
(c) Open gas shutoff valve. Restart the
appliance. The ignition sequence will
start again and the burner will start. The
appliance will return to its previous mode
of operation.
NOTE: Models 1250-2000 have two ignition controls
and two ignitors, which work together to ensure all of
the burners light properly.
6.5.2 High Altitude Adjustment and Set Up
Pennant appliances may be operated at high
altitude (7700 ft., 2347 m) with a reduction in output
of approximately 10%. At altitudes of less than or
more than 7700 ft. (2347 m) the appliance will per-
form equally as well, but with differing reductions in
output. At elevations higher than 7700 ft. (2347 m) the
reduction in output will exceed 10% and at elevations
below 7700 ft. (2347 m) it will be less than 10%. High
altitude adjustment must not be made on appliances
operating at elevations below 2500 ft. (762 m).
No orifice changes are required to adjust the
Pennant appliances for high altitude. High altitude
adjustment is accomplished by adjustment of the gas
valve manifold pressure and the air shutter(s). The
required instruments used to assist in these adjustments
are a CO
2
or O
2
Analyzer and a U-Tube Manometer or
other device capable of reading a pressure of 2.5-3.0
inches W.C. (0.62-0.75 kPa).
Start the adjustment process by checking the CO
2
in the “as installed” condition. Adjust the air shutter(s)
so that the CO
2
is about 8% or the O
2
is about 6.8% for
appliances operating on Natural Gas. For appliances
operating on LP Gas adjust the air shutter(s) so that the
CO
2
is about 9.2% or the O
2
is about 6.8%. Appliances
with two blowers should be adjusted so that the air
shutters below each blower are open the same amount.
Once the CO
2
or O
2
has been set, the manifold
pressure may be adjusted. Remove the 1/8 NPT plug
from the lower side of the gas valve that is to be set
and install a fitting, hose and manometer. Start the
appliance and observe the manifold pressure. Manifold
pressure must be adjusted to 3.0 in. W.C. (0.75 kPa)
(for high altitude only, standard operating pressure is
2.5 in. W.C. (0.62 kPa)). It is adjusted by removing the
slotted cap on the gas valve and turning the adjustment
screw (beneath the cap) clockwise to increase
pressure and replaced after the adjustments have been
completed and the fitting, hose and manometer have
been removed and the 1/8” plug has been replaced.
Repeat this process until all gas valves have been set.
Note: The pressure can be set only when the appliance
is operating and only when the particular gas valve
being adjusted is energized by a call for heat from the
staging control.
After all of the gas valve manifold pressures
have been set, the CO
2
or O
2
must be reset. CO
2
or O
2
will have changed when the manifold pressure was
adjusted. Open the air shutter(s) to reduce the CO
2
or
O
2
to the values achieved previously.
The procedure is complete when all gas valves
are adjusted to a manifold pressure of 3.0 in. W.C.
(0.75 kPa) and the CO
2
is adjusted to 8.0% for Natural
Gas appliances or 9.2% for LP appliances. When using
an O
2
analyzer, the correct O
2
is 6.8% for both Natural
Gas and LP appliances.
CAUTION
Should any odor of gas be detected, or if the gas
burner does not appear to be functioning in a
normal manner, close main shutoff valve, do not
shut off switch, and contact your heating contractor,
gas company, or factory representative.
6.6 Shutting Down the Pennant
1. Switch off the main electrical disconnect switch.
2. Close all manual gas valves.
3. If freezing is anticipated, drain the Pennant and
be sure to also protect building piping from
freezing.
This step to be performed by a qualified
service person.
6.7 To Restart the Pennant
If drained, follow Section 6.1 in this manual for
proper filling and purging.
1. Switch off the main electrical disconnect switch.
2. Close all manual gas valves.
3. WAIT FIVE (5) MINUTES.
4. Set the aquastat or thermostat to its lowest
setting.
5. Open all manual gas valves.
6. Reset all safety switches (pressure switch,
manual reset high limit, etc.).
7. Set the temperature controller to the desired
temperature setting and switch on electrical
power.
8. Burner will go through a pre-purge period and
ignitor warm-up period, followed by ignition.