LAARS Pennant PNCV (Sizes 500-2000) - Install and Operating Manual - Manual (Page 47)

Pennant (500-2000) Page 47
(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: Sizes 1000–2000 have two ignition controls
and two ignitors, which work independently of one
another. If the ignition control for stages 1 and 2 fails
to properly light the main burners for those stages, the
second ignition control will still be active, and will be
able to energize stages 3 and 4. This, of course, will
only occur if all other safety devices confirm that the
unit will run in a safe condition.
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 approx-imately 10%. At altitudes of less than
or more than 7700 ft. (2347 m) the appliance will
perform 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
adjust-ments 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 prepurge period and
ignitor warm-up period, followed by ignition.