Compressor Protection; Hot Gas Temperature; High Pressure Control; Low Pressure Control - Nibe F2040 Technical Manual

Compressor protection

Hot gas temperature

When the hot gas temperature (Tho-D) indicates an
unusually high temperature during operation, the
speed decreases to cool it down.
Speed control of the compressor:
When the temperature is greater than 105 °C, the
■
speed is reduced by 4 rps/minute
When the temperature is between 100 to 105 °C, no
■
speed changes occur.
When the temperature is below 100 °C, the function
■
stops.
Stop with automatic reset:
The compressor stops when the temperature is
■
115 °C, and restarts when the temperature is below
85 °C
Stop with manual reset:
If the above occurs 2 times within 60 minutes, or the
■
temperature is greater than 115 °C for 60 minutes,
the compressor stops with error code "E36".
Resetting can occur 45 minutes after the temperature
■
has dropped below 85 °C.

High pressure control

Heating operation:
F2040:
The speed of the compressor decreases by 4 rps every
30 seconds when the fluid line sensor (BT 15) or con-
densing temperature (BP 4) is 60 °C, at the same time
as the high pressure switch is deployed.
The compressor stops when BT 15 or BP 4 reaches 65 °C
and restarts when the temperature is <= 47 °C.
The compressor stops when Tho-R reaches 65 °C and
restarts when the temperature is <= 51 °C.
Cooling operation:
The speed of the compressor decreases by 4 rps every
minute when Tho-R is 60 °C, at the same time as the
high pressure switch is deployed.
The cut-out point is reduced by 2 °C every time the high
pressure switch deploys, down to 54 °C.
Stop with manual reset:
The compressor is stopped with error code "261":
if the pressure switch trips 5 times within 60 minutes.
■
If the break temperature for the compressor is
■
reached for more than 60 minutes.

Low pressure control

Speed control of the compressor:
The speed of the compressor decreases by 4 rps every
30 seconds if the low pressure is 0.15MPa or lower for
more than 10 seconds. The function is stopped when
the low pressure is 0.189 MPa or greater.
24 Chapter 4 | Description of functions
Stopped compressor:
When one of the following conditions is met, the
compressor stops.
The low pressure is less than 0.015 MPa for more
■
than 15 seconds.
The low pressure is less than 0.15 MPa and overheat-
■
ing is greater than 30 °C for more than 60 seconds.
Compressor operation is resumed automatically when
the low pressure is 0.227 MPa or greater.
Stop with manual reset:
If the above events occur 3 times within 60 minutes,
or the low pressure is lower than 0.079 MPa for more
than 5 minutes, the compressor is stopped with fault
code "E 49".
High compression ratio:
If the low pressure is less than 0.28 MPa and if the fluid
line sensor or condensing temperature is greater than
50 °C, the compressor speed can be lowered.
NIBE™ F2040