LAARS Pennant PNCV (Sizes 500-2000) - Install and Operating Manual - Manual (Page 36)

LAARS Heating Systems Page 36
SECTION 6.
Operating Instructions
6.1 Sequence of Operation
A call for heat can be initiated either
automatically (auto mode) under thermostatic control
by the Pennant temperature control, or by an external
contact closure (manual mode).
In auto mode, the Pennant burner will fire
its stages of input to maintain a target temperature
programmed into the temperature control. The
controller can be programmed per Section 6.3.
In manual mode, an external control will control
the Pennant stages, as long as the Pennant control is
set to mode 6, and the auto/manual switch (located
inside the control compartment) is set to manual.
The amber READY light on the front panel
indicates that the control system is energized. Upon
a call for heat, the green HEAT indicator on the front
panel will light.
If the unit is pump-mounted, the pump will be
energized. The pump terminals on the field-wiring
terminals strip will energize a field pump that is
properly interlocked with the Pennant. The green
PUMP indicator on the front panel will light.
Once the water flow switch makes, and if all of
the safety interlocks are closed, the ignition module
will energize the blower(s) for a 15-second pre-purge,
followed by a 20-second period to allow the ignitor to
heat.
Energizing the blower pressurizes the air box
(which supplies air to the burners) and closes the
normally-open contact(s) of the airflow pressure
switch(es). This allows the ignition module to proceed
with the ignition sequence.
The blocked flue pressure switch senses the
pressure in the plenum. It will interrupt the airflow
sensing circuit if this pressure exceeds a maximum
value. If airflow is not proven, the ignition module
will lockout.
The ignition module checks that the ignitor
current has reached a minimum value and energizes
the gas valve at the end of the ignitor heating period.
The green STAGE 1 indicator on the front panel will
light, indicating that the stage 1 gas valve is open.
After a 4-second trial for ignition, the ignitor
switches off, and unless a flame is detected by the
flame sensor, the gas valve will close and the ignition
module will either attempt ignition again (up to three
times) or will lockout (if the optional lockout ignition
module is used).
If flame is sensed, the burner will continue to
fire as long as there is a call for heat. In Auto mode,
additional stages are delayed by a minimum of 60
seconds (less prepurge and ignitor warm-up time) and
once energized, must fire for at least 30 seconds. The
request for additional stages is indicated on the control
display, and the energizing of additional burner stages
is indicated by front panel lights.
If there is a subsequent loss of flame signal, the
burner will attempt re-ignition up to three times (only
once if optional lockout ignition module is used.)
When the call for heat is satisfied, the gas
valve(s) closes and the blower(s) continues to run
for 30 seconds. The pump will continue to run for a
minimum of 20 seconds and up to a programmable
maximum of 10 minutes.
If a call for heat is prevented from being satisfied
either by a safety interlock or due to an ignition
lockout, the red SERVICE indicator on the front panel
will light. To reset the standard ignition module,
the reset button on the module must be pressed.
Interrupting power to this module will not reset the
lockout.
The Pennant 1000–2000 models have two
ignition modules that control different burners. If
one module should fail for any reason, the remaining
module can operate its burner(s) independently.
6.2 Filling the Boiler System
1. Ensure the system is fully connected. Close all
bleeding devices and open make-up water valve.
Allow system to fill slowly.
2. If make-up water pump is employed, adjust
pressure switch on pumping system to provide
a minimum of 12 psi (81.8 kPa) at the highest
point in the heating loop.
3. If a water pressure regulator is provided on the
make-up water line, adjust the pressure regulator
to provide at least 12 psi (81.8 kPa) at the highest
point in the heating loop.
4. Open bleeding devices on all radiation units
at the high points in the piping throughout
the system, unless automatic air bleeders are
provided at such points.
5. Run system circulating pump for a minimum of
30 minutes with the boiler shut off.
6. Open all strainers in the circulating system,
check flow switch operation, and check for
debris. If debris is present, clean out to ensure
proper circulation.
7. Recheck all air bleeders as described in Step 4.
8. Check liquid level in expansion tank. With the
system full of water and under normal operating
pressure, the level of water in the expansion tank
should not exceed ¼ of the total, with the balance
filled with air.
9. Start up boiler according to the procedure in this
manual. Operate the entire system, including the
pump, boiler, and radiation units for one (1) hour.
10. Recheck the water level in the expansion tank. If
the water level exceeds ¼ of the volume of the
expansion tank, open the tank drain, and drain to
that level.
11. Shut down the entire system and vent all
radiation units and high points in the system