Carrier 50EH, Installation, Operation And Maintenance Instructions

Page: 17 / 36

Packaged rooftop units
17
Connection of the outdoor humidity probe Location of the sensors on the machine
Note: If the unit needs the outdoor humidity probe (used with enthalpic
or thermoenthalpic free-cooling), this one will be connected in B5 in the
place of the ambient probe. In this case it is necessary to use a RS485
ambient temperature probe connected on the Field-bus.
Reversing
valve
(heat pump)
Outdoor fan
Compressor
Low pressure High pressure
B3
Supply air probe
Outdoor temperature probe
B2
B7
Pressure transducer
in the outdoor coil
B1
Return air probe
B4
Mixing
probe
Discharge T
klixon switch
Fresh air
Extraction air
B5
Ambient air probe
B10
Air quality probe (opt.)
Outdoor coil
Indoor coil
Indoor fan
The outlet probe (B3) and the mixing probe (B4) can be replaced by
RS485 enthalpic probes for calculation of the cooling and heating
capacities (optional).
The outdoor humidity probe (optional), necessary for the enthalpic
free-cooling, is factory-installed on the hood of the fresh air intake.
The cable is sent rolled up and attached to the interior of the hood.
The position of the
terminal box depends on
the assembly selected for
the unit.
The installer only has to
insert the cable through
the cable gland for wiring
it in the PVC box located
inside the unit, next to the
servomotor.
Checks in the axial fans
- Before commissioning, check the blade rotation direction and that
the axis turns without strokes nor vibrations.
- Once running, check the operation conditions: pressures,
fl
ows and
consumptions.
- With (standard) electronic fans, check that they adapt their rotational
speed based on the condensation or evaporation pressure.