Example: Control of a heat pump by SMA Data Manager M
The following is required to control a heat pump via the SMA Data Manager M in accordance with the SG Ready standard:
Unused terminal X3 at the SMA Data Manager M
1 Blocking device from the electric utility company
1 Break contact relay
Wiring of example components
In the example, the first component of the binary signal comes from the utility blocking device, and the second component comes from the digital output X3 of the Data Manager. The blocked operation state is thus requested by the electric utility company via a signal value of 1. To prevent a 1 in the second position from generating a startup command, a 0 must be forced in the second position as soon as there is a 1 in the first position. This is done via the break contact relay.
A 0 from the electric utility company as the input signal in the first position means that the heat pump is allowed to operate. Via threshold-based switching, the Data Manager can change between 0 and 1, i.e., between the states 00 (Normal operation) and 01 (Encouraged operation)
Using the electronic circuit shown, the states 10 (Blocked operation), 00 (Normal operation) and 01 (Encouraged operation) can be achieved. The state 11 (Ordered operation) is actively prevented.
To implement the circuit, the digital output of the utility blocking device is connected to both the first input of the heat pump to be controlled and the break contact relay. One of the two outputs at X3 is connected with the second input of the heat pump via the break contact relay, as described in this document ( > Connection to the multifunction relay X3).
In addition, to ensure optimal performance, the thresholds and reference points that are the most appropriate for the individual system should be selected ( > Limiting-value based switching).
Also see: