Hitachi RHUE-3AVHN, Руководство по обслуживанию

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Controller pack
Service Manual
88
DHW control functions
SMGB0066 rev.0 - 12/2009
Parameter Setting •
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
Automatic reset •
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.
4.4.4. dHW Electric Heater
4.4.4.1. dHW Electric Heater
Configuration Specific
This function is only available in configurations 1 and 2 (CONF 1,2).
function 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 defined 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... .
Situation 1:
P10 < dSET_HP
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.