Mitsubishi Electric i-BX, Technical Manual

Page: 58 / 72

TM_i-BX(-N)_NC05_00_06_20_EN
MEHITS S.p.A. ● TECHNICAL MANUAL Version NC05 - Translation of the Original Instructions
58
5.2 DHW STORAGE TANK MANAGEMENT
The heating of the storage tank will be possible thanks to the heat pump and the DHW storage tank heater.
The setpoints on which the regulation will take place will be:
-
0023 comfort setpoint, setting parameter 0015 = COMFORT (typically used during the day, when time band control is set);
- 0022 economy setpoint, setting parameter 0015 = ECONOMY (typically used during the night, when time band control is set)
- 0209 overboost setpoint, a value that allows to load the storage tank at a temperature higher than the current setpoint, comfort or economy; see the
function described in p aragraph “ 5.2.3 HP + DHW storage heater ( P0202 =3) or delivery heater “.
The storage tank will work following the comfort or economy setpoint, on the basis of the value set in parameter 0015 .
DHW management may be configured as follows:
-
None: disabled from key (the domestic hot water function will be excluded);
- HP only storage tank loading : parameter 0202 = ONLY HEAT PUMP (in this case, the storage tank will only be loaded using the heat pump);
- DHW storage heater only storage tank loading: parameter 0202 = ONLY HEATERS (in this case, the storage tank will only be loaded using the
internal immersion heater);
-
HP + replacement heater storage tank loading: parameters 0202 = H HEAT PUMP, or 0202 = ONLY HEAT PUMP and 0300 = 1 (in this
case, the storage tank will be loaded using the heat pump as far as this is capable of heating the water, after which the immersion heater, or in its
absence the delivery heater, will take charge of the operation).
The individual functions are described below.
5.2.1 HEAT PUMP ONLY
The heat pump is activated to produce DHW if the temperature in the storage tank falls below the value set in parameter
0513 “DHW proportional
band”, with respect to parameters 0022 “DHW economy setpoint” and 0023 “DHW comfort setpoint”.
The HP stops producing DHW in the following cases:
a) the DHW setpoint is reached (probe B3), typical condition;
DHW storage tank T [°C]
Compressor
ON
OFF
DHW proportional
band (P 0513)
DHW setpoint
(0022 or 0023)
b) the HP is inhibited due to one of the following conditions:
automatic reset due to transducer or pressure switch high pressure;
operation outside envelope;
maximum possible produced water temperature based on the external air temperature, as defined by parameters
133E , 133F , 133H , 133R , 133S ,
133T , 0636 ;
In the b) case, the message “Max Set” will be displayed and the temperature reached by the storage tank at the time of the stop will be recorded.
This will become the new reference for the application of the “DHW proportional band” for switching the compressor back on; t he unit will only restart
to produce DHW in the following condition: DHW sto rage tank T <= “MaxSet instantaneous T” – “DHW proportional band”, again following the “DHW
economy setpoint” or “DHW comfort setpoint”, based on the function described below: