10
To decrease the airflow, loosen setscrew on the inner half
of the motor pulley, looking at the shaft end. Turn the
inner half of the pulley clockwise. After the adjustment,
the setscrew must be tightened on the flat side of the
motor shaft. Be sure that the blower belt tension is
adequate. (Refer to the maintenance section).
Figure 1 – Pulley adjustment
3.3.8
F
AN LIMIT ADJUSTMENT
Modification of the "FAN ON" and "HI" limit settings on the Fan-
Limit can cause malfunctioning of the furnace and result in
premature wear of the heat exchanger.
CAUTION
Modification of the factory set limits will void the
warranty.
Figure 2 – High limit adjustment
AMT4 , OLR350H28A
1
“FAN OFF” Limit
32°C (90°F)
2
“FAN ON” Limit
43°C (110°F)
3
“HI” Limit
93°C (200°F)
3.3.9
S
UPPLY
A
IR
T
EMPERATURE
R
ISE
T
EST
1.
Operate the burner for at least 10 minutes;
2.
Measure the air temperature in the return air plenum;
3.
Measuring the air temperature in the largest trunk
coming off the supply air plenum, just outside the
range of radiant heat from the heat exchanger. 0.3 m
(12") from the plenum of the main take-off is usually
sufficient;
4.
The temperature rise is calculated by subtracting the
return air temperature from the supply air
temperature;
5.
If the temperature rise is lower or exceeds the
temperature specified in Table 1, p. 13, change to the
next lower or higher blower speed tap, until the
temperature rise falls to the target. If the excessive
temperature rise cannot be increased or reduced by
changing fan speed, investigate for ductwork
obstructions, dirty or improper air filter, improper firing
caused by improper pump pressure or nozzle sizing.
3.3.10
L
IMIT
C
ONTROL
C
HECK
After operating the furnace for at least 15 minutes, restrict
the return air supply by blocking the filters or the return air
register and allow the furnace to shut off on High Limit.
The burner will shut off but the blower will continue to run.
Remove the obstruction and the burner should restart
after a few minutes. The time required for the restart also
depends on the adjustment of the blower “OFF” delay.
3.3.11
R
ESTART AFTER
B
URNER
F
AILURE
1.
Set the thermostat lower than room temperature;
2.
Press the reset button on the burner primary control
(relay);
3.
Set the thermostat higher than 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 hot.
Summary of Contents for AMT400B34-SM1PMA
Page 16: ...16 Figure 5 Furnace dimensions DNS 0848 Rev E...
Page 17: ...17 Figure 6 Ladder Diagram Heating and Cooling AMT400B34 SM1PMA OLR350H28B...
Page 18: ...18 Figure 7 Wiring Diagram heating and cooling AMT400B34 SM1PMA OLR350H28B DNS 1016 Rev B...
Page 19: ...19 Figure 8 Wiring Diagram Heating AMT400B34 SM1PMA OLR350H289B DNS 1021 Rev B...
Page 20: ...20 COMPONENTS AND REPLACEMENT PARTS...
Page 21: ...21 Figure 9 Parts List With 4 speed motor PSC B50043B...
Page 40: ...18 Figure 6 Diagramme en chelle chauffage et climatisation AMT400B34 SM1PMA OLR350H28B...
Page 42: ...20 Figure 8 Diagramme lectrique chauffage AMT400B34 SM1PMA OLR350H28 DNS 1021 Rev B...
Page 44: ...22 B50043 Rev B Figure 9 Liste de pi ces avec moteur 4 vitesses PSC...
