Hitachi YUTAKI Series - DHW Electric Heater

Controller pack
Service Manual
88
DHW control functions
SMGB0066 rev.0 - 12/2009

P27 Maximum allowed DHW loading time (default 1.5hr)

note
After the DHW loading has stopped, the DHW electric heater (if connected) will continue to be enabled until the -
DHW setpoint temperature is reached

Onlyafter24hrs,oratthenexttimeclockenableperiod(ifanexternalDHWtimeclockisused),thesystemcontrollerwill
use the Heat Pump once again to load the DHW tank.
 
 
 Thisfunctionisonlyavailableincongurations1and2(CONF1,2).
 The DHW tank may have an internal electric heater for situations when the
heatpump is unable to fully load the DHW tank
The Heat Pump is not able to heat the DHW tank to high temperatures by itself
because its output is limited. The maximum temperature to which the heat pump
canraisetheDHWtankisdenedas:
DSET_HP = the maximum temperature to which the heat pump can heat the DHW
tank
= Heat Pump maximum supply temperature (EP29 or EP33) – EP39
IF DSET (P10) is set less than this value then the DHW electric heater operates as
in situation 1 below.
IF DSET (P10) is greater than this value then the DHW electric heater operates as
in situation 2 below... .


If,aftertheDHWelectricheaterwaitingtime,theDHWtemperaturehasnot
reachedtheDHWsetpoint,theDHWelectricalheaterenableoutputisswitchedon.
The electrical heater operates on its own thermostat to raise the temperature of the
DHW tank.