If you have excess solar power, you can easily use it to produce hot water. The yield from the summer and transition period is often sufficient to make yourself independent of fossil fuels. The heating element or heating sword is screwed directly into the hot water tank or if this is not intended, there is also adapter what the heating element can be installed in the audit lid. Services in the area of ​​2-3kW are often sufficient to produce the hot water for the entire household during the day.
Functionality of the heating tab
A heating element consists of an electric heating element, such as it is also installed in washing machines. In addition, there is a temperature sensor that measures the hot water temperature and a safety temperature limiter (StB) that switches off the heating element when overheating.
​
When electricity lies on the heating rod, it heats up to the preset temperature as soon as it is reached, the heating element switches off automatically. If the heating rod is operated exclusively with PV surplus, it is advisable to set the desired temperature higher than in the heating, it is ensured that the normal heating only starts if there is too little sun. For example, the heating can be set to 45 ° C and the heating rod at 65 ° C then results in 20 ° C temperature buffer, which can be used up at night.
​
As a rule, lime is created in hot water production, where the manufacturer must be paid to the maintenance intervals specified. If the StB triggers, this can happen, for example, because of too high calcification. Descaling is then recommended.
What do I have to pay attention to when connecting?
In principle, electrical work may only be done by an electrician, there is danger to life. The images listed are only connection examples and not an electrical connection plan.
Of course, it is always important to ensure that the maximum output of the heating tape does not exceed that of the switch.
The heating tape must be installed by a heating installer. In improper installation, building damage can occur.
Control with a Shelly Plug
​
The easiest installation of the heating tape can be via a Shelly Plug or another supported switching socket. The heating element can only be switched on and out.
Control with a Shelly Plus 1pm
​
As an alternative to the Shelly Plug, the heating can also be controlled via a Shelly Plus 1PM. Of course, it is always important to pay attention to the maximum output of the heating tape and the relay. The heating element can only be switched on and out.
Control with 3 Shelly Plus 1pm
​
If you have a heating element that has 3x 230V connections, you can connect it via 3 Shelly Plus 1pm. The advantage is that each phase can be controlled individually. So you can operate steps in 1kW with a heating rod with 3 kW and thus achieve even more self -consumption. Of course, it is always important to pay attention to the maximum output of the heating tape and the relay.
Establishment of the control
First you have to set up the Shelly and connect to the Internet and the Shelly Cloud.
Then you can connect the Shelly to our app.
When setting up, you have to make sure that you keep the correct nominal output. The nominal output corresponds to the connecting performance of your heating tab, or when connected via 3 Shelly 1/3 of the nominal output. As soon as the surplus exceeds the set nominal output, the heating element is activated.
In the settings of the electricity meter, you can use the ECO-offset to define which performance at least for the building is kept as a buffer or which network cover is allowed before a switch switches off.
​
For example, if your Eco-Offset is 200W, at least 200W is always fed into the public network. If the feed -in is less than 200 W, the switch is switched off. For example, if the Eco -Offset is -500 W, a network cover is allowed. The switch is only switched off when more than 500 W are obtained from the network. In this way you can adapt the control to your individual needs and system dimensioning.