Industrial Plugs Explained: Popular Features and Compatible Combinations

Plugs and sockets play a crucial role in the electrical system of both residential and commercial buildings. While people don’t pay much attention to the plugs inside their home until something is obviously wrong with them, owners of commercial buildings, like factories, must always be on their toes. This is due to the fact that commercial facilities operate millions of dollars worth of equipment, which requires specific amounts of current to operate optimally.

That being said, polyphase and industrial plugs are specifically designed for use in industrial settings, as well as mobile homes and caravans that require current and voltage that’s higher than the regular current and voltage of a typical household electrical system. Industrial plugs are typically used in polyphase systems and when the electrical circuit is under stress from environmental factors.

For instance, plugs used in chemical plants or mines have extra protection simply because there are more hazards present. Some plugs have waterproof sleeves and covers, while others are interlocked to ensure the plug can’t be accidentally disconnected. 3-phase power plugs will usually feature a ground connection, but they won’t have a neutral connection because it’s usually not needed in 3-phase loads. 3-phase plugs also feature earth prongs on top of the three phases, which practically makes them four-pronged.

In Australia, New Zealand, and many South Pacific islands, industrial plugs need to meet the AS/NZ 3123 standard. The AS/NZ 3123 standard implies that each socket should accept plugs up to its rating, but not plugs with a neutral pin or a higher current rating. Single phase size one round pin sockets that are rated 250V can work with a 20 amp plug. Single phase size two round pin sockets that are rated 250V work with 32 amp plug. Single phase flat pin sockets that are 250V rated work with 10 amp, 15 amp, and 20 amp plugs. Polyphasesize 1 unique sockets that are rated 500V work with a 16 amp plug. Polyphase size 1 sockets that are 500V rated work with a 10A or 20A plug. And polyphase size 2 sockets that are rated 500V work with a 32 amp plug, 40 amp plug or 50 amp plug.

Polyphase plugs and sockets are rated at up to 500V and all of them feature an earth connection. If fitted correctly, these plugs and sockets are IP56 rated. To ensure compatibility, plugs, and sockets in one ground can only take the same plug or smaller plugs from that particular group. Each group can have certain lugs on the outside of the plug which has a higher current rating whose purpose is to prevent a plug that’s rated for a higher current from being installed into a socket that’s rated for a lower one. However, a plug that’s rated for lower current can be installed into a socket of the same group that’s rated for a higher one.