Heating System - Lennox 2PGE13 series Installation Instructions Manual

Heating
System Circulating Air Blower
With the proper thermostat and sub-base, continuous
blower operation is possible by closing the R to G circuit.
Cooling blower delay is also functional in this mode.
Heating Sequence of Operation
1. When the thermostat calls for heat, the combustion
blower is energized by the ignition control.
2. When the speed of the combustion blower reaches
proper RPM, the pressure switch closes, initiating the
pre-purge timing (30 seconds nominal).
3.
When pre-purge has expired, the ignition control
energizes the gas valve, the spark electrode, and the
flame sensor. The igniter sparks for 10 seconds, and the
flame sensor senses that flame has been established. If
the flame sensor does not sense that flame has been
established in the 10-second interval, then the ignition
control will de-energize the gas valve.
4.
The ignition control is designed to repeat this "trial for
ignition" a total of three times. If, at the end of the third
trial, a flame still has not been established, the ignition
control will repeat the trial for ignition sequence 1 hour
later. The 1 -hour retry is indefinite. The ignition control
can be reset by interrupting the unit power or the
thermostat circuit.
Depending on the package unit model, the blower motor will
be either a multi-tap PSC motor or a variable speed motor.
PSC Motor
The circulating air blower is controlled by a timing circuit in the
integrated blower/ignition control. Timings are not adjustable.
Cooling - Blower "on" delay is 30 seconds after call for
cooling. Blower "off" delay is 90 seconds after the cooling
system shuts down.
Heating- Blower "on" delay is 30 seconds nominal after
burner ignition. Blower "off" delay is approximately 120
seconds after the thermostat is satisfied.
Variable Speed Motor
Units equipped with a variable speed circulation air blower
motor will deliver a constant airflow within a wide range of
external static pressures. Other features of this variable
speed motor include:
Soft Start/Stop -The variable speed motor will slowly
ramp up to normal operating speed. This minimizes noise
and increases comfort by eliminating the initial blasts of air
encountered with standard motors. At the end of a cooling
or heating cycle, the motor will slowly ramp down.
6.
Thirty seconds (nominal) after the initial trial for
ignition, the circulation air blower will start.
When the thermostat is satisfied, the combustion
blower and gas valve are de-energized. The circulat-
ing air blower motor will continue to run for a short
period after the thermostat is satisfied.
Circulation Airflow Adjustments - The controls include
a variable speed motor interface board. The ADJUST tap
can be used to raise (+) or lower (-) the airflow by 15%.
Heating and Cooling Airflows -The units are factory set
for the correct heating and cooling airflows. However,
airflow changes can be made by moving the position of
the HEAT and COOL taps (see Table 4).
Adjusting Airflow (Variable Speed Motor Equipped Units Only)
m
_OC
ett_
iiilDii_iiiiD!!ii
24, 30 68 NORM 800 90C
36 68 100C 110,
36 90 NORM 100C 110,
42, 48; 60 83 NORM 160C 120,
42, 48, 60 110 NORM 160C 120,
42, A8,., 60 i38 160C 120,
ADJUST, HEAT,
and COOL Taps
and Dehumidify
Resistor
on interface
Board
" ..... A_S_
Table 4
Page 12 # 48111 B005