Packaged rooftop units
with integrated gas burner
12
Main door switch
By using a mechanical device,
it impedes access to the electric
panel when the unit is with
voltage.
High pressure pressostat
Connected to the compressor discharge, it will
stop its operation when the pressure at that point
reaches the setpoint. It disconnects at 42 bar and
it is automatically reactivated.
Low pressure pressostat
When connected to the compressor suction, it
will stop its operation when the pressure at that
point goes down below the tare value (caused by
obstructions in the circuit, excessive dirt in the fi lters, fan stop or ice
formation in the evaporator).
It disconnects at 2 bar and it is automatically reactivated.
Safeties at the compressor
The scroll type compressor that these units as standard have the
following safeties:
- Non-return valve built into the compressor.
- Klixon in the compressor, which stops the operation of the motor
when there is excessive heating.
Condensation and evaporation pressure control
This safety element, integrated in the control, enables managing the
outdoor fans when the units are working in COOLING mode with low
outdoor temperatures (condensation control) or in HEATING mode with
high outdoor temperatures (evaporation control).
This aids the unit's operation in all the stations.
Smoke detector (optional)
This smoke detection station uses a LED to indicate the installation
status and if the probe detects the presence of smoke in the installation
it stops the operation of the unit. The station is installed in the factory
in the auxiliary electric panel.
Smoke detecting station
Smoke detecting probe
Clogged fi lter detector (optional)
Differential pressostat for indication of maintenance to fi lters. Automatic
reactivation. It is installed in the auxiliary electric panel.
Anti-fi re safety device
This safety device, integrated in the control, shuts down the unit if the
probe located in the return detects an air inlet temperature above
60ºC. The unit will not return to operation until this temperature drops
under 40ºC.
Control of air fl ow
Differential pressostat that measures the fl ow variation in the air outlet.
This allows the detection of fan belt breakages, since the fan relay only
detects operating faults that have arisen in the motor. This pressostat
is installed in the factory in the auxiliary electric panel.
Protection of the electric panel (optional)
Anti-freeze protection for low outdoor temperatures with electric heater.
This safety device is compulsory when the outdoor conditions guarantee
an air inlet temperature to the burner which is less than -15ºC.
Air quality probe (optional)
This probe is for installation in the environment or in duct to enable
measuring CO
2
and/or volatile compounds.
This probe is to be connected by the client. The clamps on the terminal
board on the main panel used for the connection are indicated on the
wiring diagram provided with the unit.
This probe is supplied inside the main electric panel.
Automatic switch in the control circuit
Magnetothermal switch that protects the operation circuit against
continuous surges as well as against high currents of short duration
(short circuits).
Defrost control
This safety element is intended to eliminate ice which could accumulate
in the outdoor coil when the unit is working in the heating CYCLE.
Defrosting is carried out by the control depending on the value
measured by the sensors on the outdoor coils and the time set between
defrosting operations.
Magnetothermals for line protection
They are located at the beginning of the power lines of the compressor
and motorised fans to protect them.
Safety devices in the 48EN/EH unit
Summary of Contents for 48EH
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