Cooling only
Head pressure controller:
wiring from temperature sensor to printed circuit board
쐃 Outdoor unit
쐇 Indoor unit
햴 Head pressure sensor
햵 Loss of refrigerant
pressure switch
햷
햴햷햵
쐃쐇
햶
38BCS...G
햶 High pressure cut-out
햷 Anti freeze thermostat
38BCS…G units are designed to work in North European climates.
These versions are identified on the 5th digit, "S" of their code
number.
R-410A versions are identified on the 8th digit “G” of their code
number.
They differ from the standard ones for the following factory fitted
accessories: head pressure controller (HPC), loss of refrigerant
pressure switch (LRPS) and high pressure cut-out.
Operating range
Minimum ambient temperature:
min. –5°C max. +43°C (mod. 009)
min. –10°C max. +43°C (mod. 012, 014)
Power supply
Nominal single-phase voltage: 230V ~ 50Hz
Operating voltage limits min. 198V
max. 264V
Features
– HPC and HIP Remote Manual Reset.
The head pressure controller allows operation in cooling
mode up to –5°C (mod. 009) and –10°C (mod. 012,
014) ambient temperature keeping the condensing
temperature always above 41°C - 42°C.
– LRPS Loss of refrigerant pressure switch: brazed between
outdoor coil and expansion device. When unit is
working, the pressure “high side” drops below 345kPa
(3.45 bar; 50 psig) for refrigerant losses, the
compressor cannot restart.
Set point
– open at 345 kPa (3.45 bar; 50 psig) pressure
– close at 650 kPa (6.5 bar; 95 psig) pressure
Head pressure controller and HIP remote
manual reset
Configuration
The Head Pressure Control “HPC” is made of two parts:
• Printed circuit board, with electronic components and quick
connector terminals.
• Temperature sensor, complete with 500 mm wiring.
For the user convenience “HIP” has been selected at automatic reset.
If “HIP” trips, cycle the power supply OFF and ON to reset the system,
because the electrical box is equipped with relais that prevent the unit
from starting, till the indoor control is switched OFF.
When head pressure drops below 3000 kPa (30 bar; 420 psig) it is
possible to restart the unit switching the indoor control ON.
Operations mode
Full voltage:
When the liquid line temperature is over the setpoint value plus half
proportional band (factory set by supplier), the output voltage to the
motor is 97% or more of supply voltage.
Low voltage:
When the liquid line temperature is below set point minus half
proportional band, the output voltage to the motor is fixed to 95V.
Hard start:
At each compressor starting the full voltage output to the fan motor
is provided for 3 seconds.
Proportional band:
The controller directly senses the changes in liquid line temperature
and varies the output voltage which causes the fan motor speed
increase or decrease.
Temperature setting
Proportional band set point +11 / –11°C
Minimum speed output voltage: 95V
Setting: the head pressure controller is
supplied factory set at 42°C
Hard start time 3 seconds.
Note:
In case of first start after a pause of several hours at –10°C, with
low voltage supply (198V) high pressure switch HIP may trip off the
unit. In this case, the remote reset by indoor control (infrared) can
be done for unit restarting.
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