Nimbus Plus S NET R32 Installation Manual UK

Electrical connections

Electrical connections 5.1 Outdoor unit electrical connections In accordance with the installation instructions, all systems for disconnecting the main power supply must have an open contact (4 mm) that guarantees full disconnection as per the indications of the Class III overvoltage conditions. a a a a Make the earth connection before proceeding with all the other electrical connections. The indoor and outdoor units must be powered separately. To avoid any risk, the power cable of the indoor and outdoor units must be installed and replaced only by specialised technicians. – Remove the front panel to access the electrical parts. – Remove the pre-cut sections (1) with the aid of a screwdriver in order to pass the electrical cables. 1 Fig. 65 Prior to accessing the terminals, all the supply circuits must be disconnected. 1-ph outdoor unit terminal board M1 M2 3-ph outdoor unit terminal board M1 GND A B L1 L2 L3 N ⏚ Mb M2 3ph Fig. 67 M1 Signal terminal board M2 230 V terminal board Mb Modbus connection between indoor and outdoor unit 3ph Connection to three-phase power supply a If the installation involves the use of thermostats or timer-controlled thermostats to manage the heat request, it is necessary to ensure that they do not have a proportional-band control logic. This logic may indeed cause inefficient behaviour of the system and fail to guarantee the fulfilment of the room temperature set-point. We recommend using modulating thermostats, modulating timer-controlled thermostats or ON/ OFF thermostats without proportional band logic. – Fasten the power supply cable (2) and the communication cable (3) between the outdoor and indoor units to the terminal board (4). – To ensure adequate resistance to pulling, the power cables must be secured using the cable glands (5) situated on the bracket (6). GND A B L N ⏚ 6 4 3 5 Mb 1ph Fig. 66 2 M1 Signal terminal board M2 230 V terminal board Mb Modbus connection between indoor and outdoor unit 1ph Connection to single-phase power supply Fig. 68 42 / EN

Electrical connections 5.2 Indoor unit electrical connections a a Before carrying out any work on the system, shut off the power supply at the main switch. Comply with the neutral and phase connections. – To access the electrical panel of the indoor unit, loosen the closing screw (1) and open the main door. – Pass the power cables (4) through the cable gland (5). – Pass the signal cables (6) through cable grommet (7). – Use the cable ties (8) to guide the cables (6). – Pass the power cables (9) of the loads through the cable hole (10) and secure them with the cable tie (11). 7 10 11 8 6 8 5 9 4 1 Fig. 69 i Fig. 71 If necessary, cut a small hole in the cable hole to facilitate the insertion of cables. Avoid excessively large holes so as to prevent air from flowing inside the appliance. – Detach the clips (2) and open the cover (3). STT 3 AL 2 MB M1 M2 S01 IN G 1 2 Fig. 72 Fig. 70 MB Modbus terminal board M1 Signal terminal board M2 230 V terminal board AL Power supply terminal board STT STT terminal board 1 Signal connections 2 230 V connections Note: secure the cables inside the appliance using the collars. 43 / EN