User Manual
26
PUMP STATION CONTROL INSTRUCTIONS
CONTROL INSTRUCTIONS 
WARNING
ESD SENSITIVE
Electrostatic discharge can lead to 
damage of electronic components.
Prior to operation of the control on the solar pump station 
the collector and tank temperature sensors must be prop-
erly connected. Remove the control cover and connect 
the sensors to the proper terminals.
COVER
CABLE CONDUITS
WITH STRAIN RELIEF
DISPLAY
PUSHBUTTONS
CAN FUSE 4A
Figure 29.
FUSE
Figure 30.
The temperature sensors should be connected to the 
following terminals with no dependence on polarity:
1 / 2 = sensor 1 (collector outlet)
3 / 4 = sensor 2 (lower heat exchanger sensor - pre-installed)
5 / 6 = sensor 3 (tank sensor)
7 / 8 = sensor 4 (upper heat exchanger sensor - pre-installed)
9/10 = VBus (see VBus note)
The power supply is connected to the following terminals:
19 = Neutral - N
20 = Line power - L
12 = Ground   
The control is equipped with two relays, one for the solar 
loop pump (upper - primary) and one for the water loop 
pump (lower - secondary)
• Relay 1 (primary pump)
18 = Line power - R1
17 = Neutral - N
13 = Ground   
• Relay 2 (secondary pump)
16 = Line power - R2
15 = Neutral - N
14 = Ground   
The controller is equipped with a VBus® for data transfer 
with an energy supply to external modules (not included).  
The connection is carried out at the terminals marked “VBus” 
and is not polarity dependent. 
SYSTEM DESCRIPTION 
The DeltaSol® BS Solex US controller is used in solar thermal 
systems with an external heat exchanger which separates 
the solar loop from the domestic hot water loop. 
The controller calculates the temperature difference between 
the collector sensor S1 and the tank temperature sensor 
S3. If this temperature difference reaches the switch-on 
temperature difference, the primary loop pump is switched 
on. If the temperature difference falls below the switch-off 
difference the pump is switched off.
If the switch-on temperature difference between the upper 
heat exchanger sensor S4 and the tank temperature sensor 
S3 is reached, the secondary loop pump will be switched on.
Figure 31.










