0
11 - eLectrIc Heater
11.1 - General
The 4GM can be equipped with an electric heater to pro-
vide heating. In this case it is equipped with an innovative
and intelligent electric heating system.
The electric heater generates air pressure drops, is mounted
on a rotation axis and oscillates between two positions:
•
a vertical position
•
a horizontal position (corresponding to the cooling
mode).
This has the following advantages:
•
obtains a higher cooling capacity
•
achieves energy savings (fan-motor assembly power
consumption lower for a given flow rate).
11.2 - description
These are high performance PTC electric resistance heaters
which make use of two technologies: electric heating and its
ability to control and limit its own surface temperature (a
state of the art technology based upon the use of ceramics).
The technology guarantees total self-regulation with abso-
lute control of the power consumption. In addition each
heater coil is fitted with a self-locking safety thermostat
which cuts out at 70°C. The actual heating power depends
upon the air flow and the entering air temperature.
NOTE: A minimum air flow is required to prevent over-
heating and incorrect cut-out of the safety thermostat. This
rate is 16.6 l/s (60 m
3
/h).
Electric heater rotation is ensured by a thermo-electric on/
off actuator. This is supplied in parallel with the valve motor
of the cold-water valve and regulated by the controller.
The assembly is installed on an access plate that can be
removed through the filter door (under the unit) - see
diagram.
The electric heater and the thermo-electric actuator can be
removed via the filter access (without removing the unit).
11.3 - removing the electric heater
WARNING: Switch off the electrical power supply before
doing any work on the unit.
If there is a malfunction in the electric heater assembly,
this must be removed. Proceed as follows:
•
Open the filter door.
•
Remove the filter.
•
Remove the CO
sensor from the unit (if this option is
installed).
•
Unscrew the two screws ‘A’ (see diagram).
•
Unclip the two cables supplying this assembly from
their cable clips.
•
Carefully pull down the plate that supports the electric
heater assembly and pull it out from the unit.
The length of the cable permits intervention on this assembly
while it is approximately 300 mm below the unit. This means
you can:
•
visually ensure the correct mechanical operation of
the assembly (correct electric heater rotation).
•
replace the PTC electric heater, ensuring that the cables
are marked before removal.
•
replace the thermo-electric actuator.
Replace the assembly by following the instructions in
reverse order.
After removing the filter, remove screws ‘A’
Screws ‘A’
