Brine Monitoring; Shunt Groups; Outdoor Compensated Curve; Curve With Seasonal Stop - Danfoss DHP-R 7Ua User Manual

2�3�4 Brine monitoring
In the master pump controller a function for brine monitoring can be activa-
ted. This function can be used, for example, to avoid very low brine temperatu-
res, to prevent freezing on the tubing.
The brine temperature sensors on all running pumps are used in the monito-
ring. For outgoing brine there is a low temperature limit. For incoming brine
there is both a low and a high temperature limit. If any of these limits are bro-
ken for a preset period of time a temperature violation has occurred. The num-
ber of running heat pumps is then limited to one less than those currently
running. If the temperature violation persists, the number of running pumps
is limited further.
When the temperature violation ceases, the limitation is gradually lifted.
2�4 shunt groups
Up to eight shunt modules can be connected to
the control system. A shunt module can control
one circulation pump and one shunt valve, and
measure one temperature. The purpose of the
shunt module is to control the measured tem-
perature using the shunt valve. The functiona-
lity can be configured for the cases described
below.
The controller is a PI-controller. An alarm is ge-
nerated if the controller error exceeds a setta-
ble limit.
2�4�1 Outdoor compensated curve
If the outdoor compensated curve function is
selected for the shunt group, the controller set
point will be dependent on the outdoor tem-
perature. A curve is used to define different set
points for different temperatures.
The circulation pump and the shunt valve will be closed if the outdoor tempe-
rature exceeds the limit Shunt 1 outdoor temp. stop. The pump and the con-
troller are started again when the outdoor temperature falls below the limit
with a hysteresis. While stopped the circulation pump is exercised at regular
intervals.
2�4�2 Curve with seasonal stop
Curve with seasonal stop is the same functionality as is used in the outdoor
compensated curve, but with the difference that it uses the master heat pump's
14 – Danfoss