Honeywell SDC Service Manual page 192

Hydraulic Components
NOTE
Boiler temperature
offset
Switching differential
Loading enabling
192
protection, pump extended running time and boiler start-up
protection no longer act on the hot-water loading pump.
Tank discharge protection
With discharge protection activated and a hot-water demand
present, the hot-water loading pump enabled only when the
temperature in the heat generator rises by more than 5 K above
the current temperature in the hot-water tank.
This measure prevents any rear tank discharge through the heat
generator. The hot-water loading pump is disabled again as soon
as the temperature differential between the heat generator and
the hot-water tank has dropped to less than 2 K.
The heat generator minimum temperature limit operates
continuously to protect the heat generator and blocks the hot-
water loading pump in case of temperatures below the set value.
ATTENTION
In case of hot-water temperature specifications above 60°C,
this function should not be activated to avoid safety switch-
off (in particular for heat generators with a low water
capacity).
Tank discharge protection must be set accordingly for hot-
water loading from buffer tanks.
This function determines the default setting of the tank loading
temperature compared to the set hot-water circuit setpoint. In
case of setpoint modifications the heating energy needed for the
hot-water supply is adjusted.
In case of several devices in the bus system and several hot-
water circuits the tank loading temperature depends on the
highest setpoint if several tanks are loaded simultaneously.
This function determines the size of the hot-water circuit switching
differential. The switching differential affects the relevant hot-
water setpoint symmetrically.
The current hot-water temperature is lower than the hot-water
setpoint by half the amount of the hot-water switching differential
SDC / DHC
EN2H-0221GE51 R0812