38
Table 7 - Pressure switch settings
Cut-out
Cut-in
Reset
High pressurestat
*2844 kPa
*1863 kPa
Automatic
Low pressurestat
*265 kPa
*363 kPa
Automatic
* Factory-calibrated
WARNING: Alteration of factory settings other than the design
set-point, without manufacturer's authorisation, may void the
warranty.
Operating limits
These units have been designed to operate within the following
limits:
Table 8 - Cooling operation
Zone
Air temperature
Dry bulb
Wet bulb
Indoor
Maximum
+35°C
+21°C
Minimum
+19°C
+14°C
Outdoor
Maximum
+46°C
-
Minimum
+19°C*
-
* With the optional head pressure control, the unit can operate with temperatures below 19°C.
Table 9 - Heating operation
Zone
Air temperature
Dry bulb
Wet bulb
Indoor
Maximum
+27°C
-
Outdoor
Maximum
+24°C
+18°C
Minimum
-15°C*
-
Control sequence
The unit is started and stopped by the remote control N1. If the
remote control N1 requires cooling or heating, the built-in
compressor short-cycle protection starts counting 3 seconds.
After this time (if high-low pressurestats, indoor and outdoor
fan thermal protectors are not tripped) the unit starts up.
OPTIONS/ACCESSORIES
-
Head pressure control (option/accessory)
-
Electric resistance heater (option/accessory)
-
Hot water coil (option/accessory)
-
Outdoor air filter (option/accessory)
-
Crankcase heater (option/accessory) - only for 50TZ and
38FZ units.
GENERAL MAINTENANCE
ATTENTION: Before starting any servicing or maintenance
operation on the unit, make sure that the power supply has
been disconnected. A current discharge could cause personal
injury.
In order to obtain maximum performance from the unit special
attention should be paid to the following points:
-
Electrical connections:
The supply voltage should be
within the limits permitted by the compressor. Ensure that
no faulty contacts exist in the terminal blocks, contactor
boards, etc. Make sure that all the electrical connections
are properly tightened, and that all the electrical
components (contactors, relays, etc) are firmly secured to
the corresponding rails.
Pay special attention to the condition of the connecting
cables between the control elements and the electrical box,
and to that of the unit power supply cable. They should
not be twisted and there should be no slits or notches in
the insulation. Check the starting and running
consumptions are within the limits specified in the
corresponding technical information.
-
Drainage:
Frequently check that the drain is not
obstructed, and that the condensate pan is clean and level.
-
Inlet filter:
This should be cleaned periodically. The
frequency depends on the purity of the entering air. The
filter may be cleaned with a household vacuum cleaner, or
by immersing it in water.
-
Refrigerant circuit:
Ensure that there is no leakage of
refrigerant or oil from the compressor. Check that the high
and low side operating pressures are normal. Make sure
that the coils are not dirty. If necessary a filter may be
installed in the outdoor air inlet. Check for unusual
compressor noise.
-
Controls:
Check the operation of all electric controls,
high and low pressurestats, etc.
SERVICE
Lubrication
Both the motors and the fans have factory lubricated and sealed
bearings, and need no further lubrication.
The compressor has its own oil supply and oil should not be
added unless a leak has occurred.