IOM SYSCREW AIR EVO HSE

35
English
6 - Control (continued)
Compressor protection
Compressors are equipped with a heating element to prevent
oil dilution, which may result in remarkable risks of failure of
compressors.
The windings of the compressors’ motors are provided with a
thermal protection.
An accessory kit for thermal protection (ACB) is available, for any
overcurrent of compressors, which shall be shop-mounted.
Electrical flow switch
A electrical flow switch must be installed, to prevent the unit working
in case of insufficient circulation of the chilled fluid.
WARNING
The electrical flow switch must be carefully
installed, according to the instructions given by
the Manufacturer.
The electrical flow switch must be installed on the pressing side
of the circulation pump for the fluid, just upstream of the heat
exchanger’s inlet. The electrical flow switch must be installed in a
horizontal straight length of piping, in a position reasonably far (both
upstream and downstream) from localized pressure drops (curves,
valves etc.).
Continuous Regulation of the EC brushless fans
EC brushless fans are mounted as standard and allow the unit to
work at an ambient temperature down to -10 °C.
6.5 Protection and Safety Equipment
Refrigeration system
The units are filled with R134a/R513A refrigerant fluid of non
hazardous type (group II). Safety device (pressure switch and safety
valves) with the sets below indicated are provided on the discharge
and suction line of each circuit.
Discharge Line
Pressure relief valve 22 bar.
Pressure switch 19,7 bar.
Suction line
Pressure relief valve 14.5 bar.
Pressure switch 0.5 bar.
Frost Protection for the Chilled Fluid
These units are provided with frost protection for the chilled fluid. This
protection consists of an electrical resistor positioned in contact with
the coolant/circulating fluid exchanger, which is activated (although
the unit is off) when the temperature of the fluid drops below 5 °C -
the standard value for a non-glycol unit.
If the leaving water temperature drops below 4 °C (standard value for
a non-glycol unit) the machine’s antifreeze alarm is activated. If the
circulating fluid is water, before the beginning of the cold season it is
advisable to drain the circuit to prevent water frosting.
If the circuit cannot be drained, it is essential to avoid de-energizing
the unit, so as to permit the activation, when necessary, of the frost
protection.
6.4 Setpoint
Pressing the Set key allows you to enter the Set point level accessible to the user. The parameters that can be set are listed below, along with the
limit values and the default values (standard shop settings):
User parameters Control mode Min value Max value Default
Cooling Setpoint
RWT Return Control 8 18 12
LWT Leaving Control 5 15 7
Cooling Setpoint - glycol water 10%
RWT Return Control 3 18 12
LWT Leaving Control 0 15 7
Cooling Setpoint - glycol water 40%
RWT Return Control -5 18 12
LWT Leaving Control -8 15 7