Energy Safe Victoria, an independent technical regulator for electricity, gas and pipeline safety in Victoria, has published an alert relating to wiring split system air conditioners.
The alert has been issued following a technical issue with the installation of wiring between the outside unit (compressor) and the (head) indoor unit on various split system air conditioners.
The technical issue is with the interconnecting cable terminals of both the indoor and outdoor units; these terminals are labelled S1, S2 and S3 but are also distinguished by use of colour:
| Terminal | Colour | Technical issue |
| S1 | Black | Connects directly to the incoming active conductor (L ∼) |
| S2 | White | Connects directly to the incoming neutral conductor (N ∼) |
| S3 | Red | Red communication — no issue |
Electricians are incorrectly connecting the wiring installed between the indoor and outdoor units to the terminal colour coding, resulting in the black conductor becoming an active conductor, the white conductor becoming a neutral conductor and the red conductor being communication.
The wiring installed between the outside unit and the indoor unit is classified as installation wiring and shall comply with the conductor insulation colours as specified in Table 3.4 of AS/NZS 3000:2007.
Should an electrician encounter this situation, immediate rectification is required, said Energy Safe Victoria in the alert.