Connection Of Cable “Boil In” / “Boil Out” In The Boiler Replacing Dhw Ntc Sensor - Bosch HP270-2 Technical Manual

Pict.29 – Connection of cable "boil IN" / "boil out" in the boiler replacing DHW NTC sensor
Specifications:
T min – lower limit of temperature in storage tank to allow start up of Electric Heater .
- default setting is 35ºC and values can be selected between 20ºC and "Tset-3ºC".
"dTon" – setting for temperature differential at which the E-heater 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.
"dTof" – setting for temperature differential at which the E-heater is switched OFF
- default setting is 10ºC (available range from 4ºC – 20ºC)
Note: the differential temperature for comparison with defined/default "dtof" is measured as:
T dif = T coil – T tank
- 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.
Attention: The differential between "dton" and "dtof" must be at least 2ºC:

doff - don ≥ 2ºC (hysteresis)
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(note: exemplificative drawing – not model specific)
6-720-821-364 SM HP270 – 250 - 200 2016/12 en