Specifications; Connections In The External System Box – “Sol” - Bosch HP270-2 Technical Manual

The 2 supplied NTC sensors, should be connected according scheme below in order to optimize the solar thermal
energy detection when solar pump is activated by the solar control.
NTC sensor in Tank Pocket

Specifications:

T min – lower limit of temperature in storage tank to allow start up of HP .
- default setting is 35ºC and values can be selected between 20ºC and "Tset-3ºC".
"dTon" – setting for temperature differential at which the HP is switched ON
- default setting is 6ºC (available range from 2ºC – 10ºC)
Note: the differential temperature for comparison with defined/default "dton" is measured as:
T dif = T tank – T coil
- T tank = minimum value measure by T top in HP or T tank (supplied sensor assembled in pocket at middle
of the tank)
- T coil = value measure by supplied sensor assembled in inlet of indirect coil.
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Pict.26 – Connections in the external system box – "Sol"
6-720-821-364 SM HP270 – 250 - 200 2016/12 en
NTC sensor in Coil