Nibe S1255 - Page 30

Climate system
To set the correct flow in the climate system, the heating
medium pump must run at the correct speed. S1255 has a
heating medium pump that can be automatically controlled
in standard mode. Certain functions and accessories may
demand that it be run manually, in which case the correct
speed must be set.
This automatic control takes place when the compressor is
running and sets the speed of the heating medium pump,
for the relevant operating mode, so the optimum temperat-
ure difference between the supply and return lines is ob-
tained. During heating operation, the set DOT (dimensioned
outdoor temperature) and temperature difference in menu
7.1.6.2. are used. If necessary, the maximum speed of the
circulation pump can be limited in menu 7.1.2.2.
Pump adjustment, manual operation
Brine side
S1255 has a brine pump that can be controlled automatically.
For manual operation: deactivate "Auto" in menu 7.1.2.7 and
then set the speed according to the diagram below.
Caution
When an accessory for passive cooling is used, the
brine pump speed must be set in menu 7.1.2.7.
Set the pump speed when the system has come into balance
(ideally 5 minutes after compressor start).
Adjust the flow so that the temperature difference between
brine out (BT11) and brine in (BT10) is between 2 - 5 °C. Check
these temperatures in menu 3.1 "Operating info" and adjust
the brine pump’s (GP2) speed until the temperature differ-
ence is obtained. A large difference indicates a low brine
flow and a small difference indicates a high brine flow.
Available pressure, kPa
Electrical output, W
S1255 6 kW
60%
100%
80%
40%
0
0
0,1 0,2 0,3 0,4 0,5 0,6 0,7
80
60
40
20
100
120
140
160
0
80
60
40
20
100
120
140
160
(kPa) (W)
Flöde
(l/s)
P 100%
P80%
P60%
P40%
Available pressure
Flow
Output
S1255 12 kW
(kPa) (W)
Flöde
(l/s)
0
0
,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7
40
20
60
100
160
140
80
120
180
200
0
80
60
40
20
100
120
140
160
180
200
40%
60%
80%
100%
P100%
P80%
P40%
P60%
Available pressure
Flow
Output
S1255 16 kW
60%
100%
80%
40%
0
0
0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8
80
60
40
20
100
120
140
160
180
200
0
80
60
40
20
100
120
140
160
180
200
(kPa) (W)
Flöde
(l/s)
P 100%
P80%
P60%
P40%
Available pressure
Flow
Output
Climate system
S1255 has a heating medium pump that can be controlled
automatically. For manual operation, deactivate "Auto" in
menu 7.1.2.2 and then set the speed according to the dia-
grams below.
The flow must have a suitable temperature difference for
the operating case (heating operation: 5 - 10 °C, hot water
generation: 5 - 10 °C, pool heating: approx. 15 °C) between
controlling supply temperature sensor and return line sensor.
Check these temperatures in menu 3.1 "Operating info" and
adjust the heating medium pump (GP1) speed until the
temperature difference is attained. A large difference indic-
ates a low heating medium flow and a small difference indic-
ates a high heating medium flow.
NIBE S1255Chapter 6 | Commissioning and adjusting30