TM_i-BX(-N)_NC05_00_06_20_EN
MEHITS S.p.A.
●
TECHNICAL MANUAL
Version NC05 - Translation of the Original Instructions
55
4.16
DEMAND LIMIT
This function can be activated using the DI8 digital input when parameter
019C
= DEMAND LIMIT. Its purpose is to inhibit the operation of the heat
pump and the delivery heaters (if present), due to them being electric loads. This is to avoid electric line overload, for example if the switching on of
other loads with higher priority than the heat pump is required.
Only the boiler stays on, if present, to meet the needs of the system, and the DHW heater in case of DHW request.
With the contact active, only the antifreeze protections will be active, and therefore the heaters and pumps of the corresponding exchangers.
If the contact is activated during defrost, the heat pump will only be stopped when defrost has been completed.
In case of activation of the demand limit, if there is a DHW request the corresponding immersion heater switches on, if configured.
When the demand limit stops, if TDHW<
0022
or
0023
, the heater switches off; if
0022
or
0023
<TDHW>
0209
, the heater stays on until “set overboost”
(
0209
) is reached.
For the default values of the various parameters, see the parameters table
4.17
TRAY HEATER
This function can be enabled using the parameter and is used to activate the heater in the defrost water collection tray, to avoid that the same freezes
due to the low external air temperature. The heater is activated based on the function described below:
Active
OFF
Tray heater
External air T (B4) [°C]
Tray heater enable
setpoint
(133I)
Tray heater disable
hysteresis
(133L)
For the default values of the various parameters, see the parameters table
4.18
CURRENT OPERATION MODE NOTIFICATION
The digital outputs configured as summer/winter will be activated based on the set operating mode - interface, digital input or supervision -, and
following this logic: contact closed = cool; contact open = heat.
The contact logic may be inverted using parameter
019E
“Logic output SUM/WIN”.
For the default values of the various parameters, see the parameters table.
