6 - MANAGEMENT AND CONTROLS
6.1 - INTERNAL UNIT ADDITIONAL ELECTRIC HEATERS MANAGEMENT
The internal unit is equipped with two electric heaters. The electric heaters are enabled to integrate power
in heating mode, domestic water production mode, during the execution of the Anti-Legionella cycles or for
start-up of the system in case of low temperatures or in building sites for screed drying.
Parameter "ADDR217"
0 = not enabled
1 = one heater enabled for backup
2 = two heaters enabled for backup
3 = one heater enabled for low-temperature start
4 = two heaters enabled for low-temperature start
6.1.1 - Backup
The first electric heater EH1 activates if:
- The heat pump has been in heating mode or domestic hot water production mode for at least ADDR235
minutes.
- The external ambient temperature is lower than ADDR227 degrees Centigrade.
- The delta on water is at least 4°K with respect to the setpoint.
After further 15 minutes from the activation of the first electric heater, if these conditions persist, the second
electric heater activates.
The backup function with electric heaters is not active if the external heat source ADDR226 is enabled (ON).
6.1.2 - Low-temperature start
The heaters intervene to ensure start-up even in conditions of low temperature of the hydraulic circuit water
(conditions which occur occasionally as, for instance, before start-up of the system or when it is necessary
to dry the screed).
Once the hydraulic circuit water reaches a temperature of approximately 12°C, the heaters switch off and
normal operation of the heat pump is restored.
6.1.3 - Legionella prevention function
The Legionella prevention function is governed by the parameters from ADDR228 to ADDR233 and ADDR217.
The parameter ADDR229 differentiates three macro modes:
ADDR229=0
The Legionella prevention function is obtained by means of the combination of the main heat pump and of
an optional electric heater (output K5).
The production of domestic hot water is managed with a temperature probe T3 ADDR228=2 and the Le-
gionella prevention function is enabled (ADDR230>0), then the machine works as follows:
- It starts at the time ADDR231 and every ADDR230 days starts water heating until temperature ADDR232
is reached.
- When the machine reaches temperature ADDR232, it maintains it within 2°C for a time equal to ADDR233;
if temperature ADDR232 is not reached within 7 hours from start-up, once 24 hours have elapsed, the
machine tries again and the alarm E08 appears at the second failure.
ADDR229=1
The Legionella prevention function is obtained by means of the sole optional electric heater (output K5)
and maintains the same modes described in the parameter ADDR229=0.
ADDR229=2
The Legionella prevention function is obtained by means of the two electric heaters EH1 EH2.
The production of domestic hot water is managed with a temperature probe T3 ADDR228=2 and the Le-
gionella prevention function is enabled (ADDR230>0), then the machine works as follows:
- It starts at the time ADDR231 and every ADDR230 days stops any other heating or cooling function in
progress using the sole electric heaters (to be enabled with parameter ADDR217).
- It maintains the same modes described in the parameter ADDR229=0.
Output K5 cannot be connected directly to the heater, add an external relay with appropriate electrical
specifications.
EN - 44