Protection Menu / 8.5 - ODU Heating Cable
Most models of the outdoor air conditioner include a heating cable in the chassis for defrosting the condensed water that runs down into the lower part of the unit and drains away.
However, this heating cable is often activated by the outdoor unit even when it is not necessary (usually permanently below +2°C), which unnecessarily increases electric energy consumption. MiniHPC offers the possibility to use one of the outputs R1, R2, R4, or R5 to control the switching of this heating according to the set criteria.
Please note that commissioning this function requires an intervention in the outdoor unit and the installation of a 2-conductor cable that connects the heating spiral of the outdoor unit with an output relay on MiniHPC.
Relays R1 and R4 are available only if DHW heating in the menu DHW heating is not activated. Relay R2 is available only if the space heating supplementary heating in the menu space heating is not in use. Relay R5 is available if, during cooling, the 3-way valve configured in the menu 3-way valve is not activated.
If relays R1 or R2 are used, these outputs can be directly connected to the interrupted wire of the outdoor unit's heating, as shown in the following diagram:
If relays R4 or R5 are used, an auxiliary relay must be inserted between the relay output and the interrupted wire of the outdoor unit's heating, as shown in the following diagram.
An example of the connector labeled HEAT-B on the PCB of the outdoor unit is shown. This particular example is from the service manual of the Gree Clivia air conditioner.
In most cases, it is the green connector with orange wires.
On the connector labeled HEAT-B, one of the wires supplying the ODU heating spiral is cut. A 2-core cable with suitable terminals is then connected to the cut ends. The other end of the cable is connected to the selected output relay of MiniHPC (or to an auxiliary relay).
specifies the outdoor temperature below which the heating will be activated. determines how long the outdoor unit’s heating (via the selected output relay) will remain activated. The heating turns on at the moment defrosting of the outdoor unit is activated. adds an additional time to the set , which depends on the difference between the setting and the actual outdoor temperature during defrosting. A lower outdoor temperature prolongs the overall defrosting time. For example, if the is set to 0°C, the is set to 30s/1°C, the is 5 minutes, and the outdoor temperature is -10°C, then the heating will be activated for 10 minutes (5 minutes + 10 × 30 seconds).