Use Of A Heat Pump; Operation; Start-Up; Use Of Manual Furnace Controls - SUPREME FEM10-M2401AM-B Guide D'installation

during a call for heat. Refer to the wiring diagrams for the
location of the relay (RAcc) on the control panel.
2.7.2.

Use of a heat pump

When using a heat pump, a thermostat with dial fuel option
or a fossil fuel kit is required that prevents the operation of
the electric elements and the heat pump at the same time.
Refer to the instructions provided with the thermostat or the
"Fossil Fuel" kit for the proper wiring of the furnace and the
heat pump.
The simultaneous operation of the electric elements and the
heat pump will cause overheating of either unit. The safety
controls of the appliances will shut down the elements or
heat pump, since they are not designed to function in this
fashion.
3.0

OPERATION

3.1

START-UP

Before starting up the unit, be sure to check that the
following items are in compliance:
1. The electrical installation and ventilation;
2. The blower access door is in place and the blower rail
locking screws are well tightened;
3. The blower speed adjustments for heating and air
conditioning are appropriate and according to the
specifications in this manual;
4. The thermostat of the room is in the heating mode and
is set higher than the ambient temperature.
To start the unit, turn the main electrical switch on.
3.2

USE OF MANUAL FURNACE CONTROLS

When there is a demand for heat, the pilot light ("L-1")
comes on. Refer to the wiring diagram.
When the "HI/LO" switch is put into the "LO" position, it will
shut down approximately half the elements.
However, it is important to put the switch back to the
"HI" position during the winter months to ensure
adequate heating.
Also, this switch must remain in the "HI" position when a 2-
stage or outdoor thermostat is used to control the electric
elements of the second stage.
Section 2.5) above (Typical 24 VAC Wiring, Thermostat).
The "ON/OFF VENT/FAN" switch engages the blower in the
continuous speed mode. This will filter the air and provide
for better air distribution in the building.
The circuit breaker is there to protect the motor and control
circuit conductors. If the unit does not function, press the
circuit breaker button to see if it may have disengaged due
to a power surge. If the breaker has to be pressed again,
the unit must be checked by a qualified service technician.
Refer to the diagram in
Figure 8 : Manual Furnace Controls
3.3

OPERATING SEQUENCE

3.3.1.

Heating mode

1. The thermostat closes the R-W1 circuit (24 VAC),
thereby activating the first 22 VDC relay passing by a
rectifier control. Without delay, the first heating element
is activated and the blower starts at low speed. On 15
kw unit power and more, a second relay is activated
after a 5 seconds delay to start one or two heating
elements depends on the unit power.
2. The thermostat closes the R-W1 & W2 circuit (24 VAC),
thereby activating another 22 VDC relay passing by a
rectifier/timer with a 8 seconds delay (there is 2 relays
for the 27 kw unit). The heating elements of the second
stage are activated after the 8 seconds delay. The 24
VAC relay of the heating speed is also activated and
heating blower speed start.
3.3.2.

Cooling mode

1. The thermostat closes the R-G circuit, thereby activating
the 24 VAC R-1 relay. The blower starts up to cooling
speed.
2. The thermostat closes the R-Y contact, thereby
activating the compressor relay of the air conditioner.
3.3.3.

Continuous Fan speed

The blower will also start up to cooling speed by way of the
"Fan" switch on the thermostat.
3.4

AIRFLOW VERIFICATION

Verify the airflow by taking readings of the following points,
while the elements are in the heating mode:
a. Total amperage of all the heating elements;
b. Voltage at the furnace;
c. Supply air temperature. The point of the reading must
not be affected by radiant heat from the elements;
d. Return air temperature.
From these readings, one can arrive at an approximate
calculation of the average airflow. To do that, the following
formula should be used:
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