Mitsubishi Electric i-BX, Technical Manual

Page: 46 / 72

TM_i-BX(-N)_NC05_00_06_20_EN
MEHITS S.p.A. ● TECHNICAL MANUAL Version NC05 - Translation of the Original Instructions
46
4.11.3 ANTIFREEZE HEATER
With antifreeze enable parameter
0310 = ON , the heater will switch on following the criteria described in the “ Exchanger antifreezee ” paragraph.
The heater is inhibited if the “Demand limit” contact is active (see the “ DEMAND LIMIT ” paragraph)
4.11.4 DEFROST HEATER
With defrost enable parameter
0302 = ON, during the defrost cycle the heater switches on following the heat setpoint and adjusting as described in
the “ Integration heater ” paragraph.
For the default values of the various parameters, see the parameters table
4.12 ALTERNATIVE HEAT SOURCE (BOILER)
The alternative heat source behaves in the same way as the delivery heater, with the exception that the heating mode (MANUAL or AUTO) cannot
be selected. For the details see the “ 4.11 ELECTRIC HEATER AT THE DELIVERY ” paragrap h. For this function there are dedicated regulation
parameters.
4.12.1 REPLACEMENT HEAT SOURCE
Refer to paragraph “6.11.1 Replacement heater ”, replacing the heater parameters as follows:
010G
→
010H
0303 → 0306
The boiler hysteresis is also managed through parameter 0316.
By introducing parameter
0316 , boiler regulation is ON-OFF, without delays or integrals:
the boiler is switched off with B7 >= 0153 (or the climate control calculated setpoint)
the boiler is switched on with B7 <= 0153 (or the climate control calculated setpoint) - 0316 .
Always taking into account the enabling on the basis of the external air temperature.
Differently from the heater situation, with the boiler as alternative source, in case of triggering of the system primary flow switch the boiler is not
disabled.
With the heat source active, the unit pump stays off.
When the “Boiler Backup” contact is activated and the heat source is on as replacement based on the external air limit defined by parameter 0311 ,
the heat pump restarts.
If the heat pump is on as replacement based on the external air limit defined by parameter
133Z , the heat pump cannot restart as it is inhibited due
to the external air absolute limit.
For the default values of the various parameters, see the parameters table