CALIDO1
DHW heat pump with tank
27
11.4
MAIN LOGICS
11.4.1 Water temperature difference for compressor starting
Parameter 1 “offset temperature TS6” is used to control the start or stop of the compressor.
When the lower temperature of tank T2 is below the temperature set TS1-TS6, the compressor runs to heat the water to temperature set TS1.
The display always shows the upper temperature of tank T3.
11.4.2
External pump
T2: lower tank temperature
T3: upper tank temperature
Check to be done to use the external pump:
•
Parameter 14 is configured;
•
The optional probe T6 has been electrically and hydraulically connected;
•
The external flow switch (optional) has been electrically and hydraulically connected;
•
an external pump (not supplied) has been electrically and hydraulically connected.
When used for sanitary hot water circulation, the pump will start when the below conditions are satisfied at the same time:
1. the unit is 'ON';
2. T3 ≥ parameter 15+parameter 16;
3. T6 ≤ parameter 15-5°C
The pump stops when one of the following conditions is met:
1. the unit is 'OFF';
2. T3 ≤ parameter 15-2°C;
3. T6 ≥ parameter 15
When used for solar water circulation, the pump will start when the below conditions are satisfied at the same time:
1. the unit is 'ON';
2. T6 ≥ T2+parameter 17
3. T2 ≤ 78°C
The pump will stop when one of the below conditions is satisfied:
1. the unit is 'OFF';
2. T6 ≤ T2+parameter 18
3. T2 ≥ 83°C
Pump anti-block function: when the pump stops for 12 hours, it will be forced to run for 2 min.
11.4.3
Flow switch
When the pump has been running for 30 sec, if the flow switch contact is detected as open for 5 sec, the pump stops. The pump restarts after 3
min. If the malfunction occurs 3 times in 30 min, the pump cannot restart until the unit is disconnected and restarted. The relevant error code
will be shown on the display. Only the pump stops but not the whole unit.
11.4.4 Thermal protections
First step protection: when the tank water goes up to 85°C, the unit will stop and the relating error code will be shown on the controller. This is
an auto-reset protection. When tank water temperature goes down, the unit can start again.
Second step protection: when the tank water keeps going up and reaches 90°C, the manual reset cut-off will be active, the electrical heater stops,
unless you manual reset the protector.
To manual reset the protector, remove the frontal plastic cover and press the reset red button on the thermostat.
11.4.5 Disinfection weekly cycle
The unit is programmed to activate a weekly anti-Legionella cycle for a period of 30 minutes that brings the tank water to 70°C.
This system reduces the risk of bacteria causing various diseases, commonly known as "legionella". We ask you to read this paragraph carefully
and ask your installer/planner for explanations in order to be properly informed about the risks of spreading this disease. We strongly recom
-
mend that you read the "Guidelines for the prevention and control of legionellosis" - Approved by the State-Regions Conference in the session
of 7 May 2015 - Italy and subsequent amendments, which should also be taken as a reference when designing the system.
The operation of the disinfection cycle is as follows:
The electrical resistance is automatically activated every week at the set time (parameter 13), regardless of whether the machine is switched on
or in stand-by mode (i.e. unit switched off but connected to the power supply).
When the upper tank temperature T3 ≥ TS3 (parameter 4), the heating element is deactivated. When T3≤TS3-2°C, the resistor is activated. The
temperature T3 is maintained in the range TS3-2°C and TS3 for the set disinfection time (parameter 5), then the unit exits the disinfection cycle.
When parameter 5 (t2) is set to 0, the disinfection function is disabled.
The logic only start counting t2 when T3 has reached TS3.
Is possible set the frequency between disinfection cycles (parameter 21).
If the unit is switched off bur powered (and even if the ON/OFF contact is open), disinfection takes place with the same logic as if the unit was
switched on.
