7
CAUTION
When ducting supplies air to a space other than where
the furnace is located, the return air ducts must be
sealed and also directed to the space other than
where the furnace is located. Incorrect ductwork
termination and sealing will create a hazardous
condition which can lead to bodily harm.
Install air conditioning cooling coil (evaporator) downstream from the
supply air plenum of the furnace. If a separate evaporator and blower
unit is used, install good sealing dampers for air flow control. Cold air
from the evaporator coil going through the furnace could cause
condensation and shorten furnace life.
CAUTION
Dampers (purchased locally) MUST be automatic.
WARNING
Poisonous carbon monoxide gas hazard.
Do NOT draw return air from inside a closet or
utility room. Return air duct MUST be sealed to
furnace casing.
Failure to properly seal duct can result in death,
personal injury and/or property damage.
WARNING
Poisonous carbon monoxide gas hazard.
Install evaporator coil on the supply side of the
furnace ducting.
Evaporator coil installed in return side ducting can
cause condensation to form inside heat exchanger
resulting in heat exchanger failure. This could result
in death, personal injury and/or property damage.
PART 2
OPERATION
2.1)
SEQUENCE OF OPERATION
2.1.1) Sequence of operation - Beckett AFG and
Riello 40-F
1.
Normally open contact (T-T) on primary relay closed when
thermostat calls for heat;
2.
AFG burner: The motor starts and spark is established. The
pump pressure builds and the oil supply mechanism opens,
admitting fuel to the nozzle;
40F burner: Burner motor starts. The burner motor fan pre-
purges the combustion chamber and vent for 10 seconds,
establishing the combustion air pattern. During this time the
solenoid valve holding coil pressure is approximately 100 psig.
The solenoid valve opens, allowing oil to flow through the nozzle.
At the same time, the burner motor ignition coil produces a spark;
3.
Spark ignites oil droplets;
4.
Cad cell senses flame and burner continues to fire. Ignition
transformer ceases sparking (R40-F);
5.
After Fan-Limit control heats up to the factory set point, the
circulating air blower and electronic air cleaner starts;
6.
The circulating air blower and burner motor remain on until the
thermostat is satisfied (AFG). The ignition transformer continues
to spark (AFG). The solenoid valve remains open (R40-F);
Thermostat is satisfied :
7.
Primary relay contacts open, solenoid valve closes (R40-F),
burner fan motor shuts down. The ignition transformer ceases
sparking (AFG);
8.
The Fan-Limit control bi-metal cools down to the factory set point
of 90
o
F (32
o
C), the circulating air blower stops.
2.2)
CHECKS AND ADJUSTMENTS
2.2.1) General
During initial start-up and subsequent yearly maintenance calls, the
furnace must be thoroughly tested.
IMPORTANT
The burner must be put in operation for at least 10
minutes before any test readings are taken. For new
installations, set up the burner to the settings per Table
2, p. 12 before firing. These are rough adjustments, but
they will ensure that the burner will start and run smoke-
free in advance of fine tuning.
Open the oil bleed port screw and start the burner. Allow the oil to
flush into a container for at least 10 seconds. Slowly close and tighten
the bleed screw. The oil should flow absolutely free of white streaks or
bubbles to indicate that no air is being drawn into the suction side of
the oil piping and pump. Fire the burner. Adjust the oil pressure as
indicated in Table 2, p. 12.
2.2.2) Restart after burner failure
1.
Set thermostat lower than the room temperature;
2.
Press the reset button on the burner primary control (relay);
3.
Set thermostat higher than the room temperature;
4.
If the burner motor does not start or ignition fails, turn off the
disconnect switch and CALL A QUALIFIED SERVICE
TECHNICIAN.
CAUTION
Do not attempt to start the burner when excess oil has
accumulated, when the furnace is full of vapour, or
when the combustion chamber is very hot.
