How to match an industrial plug to a socket: current, poles, voltage and position
Industrial plugs and sockets made to the IEC 60309-2 system are coded so that a plug only fits a socket of the same current rating, number of poles, voltage and earth-contact (clock) position. If any one differs, the parts are designed not to mate, which stops a plug being connected to the wrong supply.
Check these four, in this order
- 1Current (A)Standard ratings are 16, 32, 63 and 125 A; larger ratings exist for heavy-duty use.
- 2PolesCount the contacts: 3-pole is typically phase, neutral and earth; 4-pole is three phases and earth; 5-pole is three phases, neutral and earth.
- 3VoltageThe voltage range is stated on every product page, and the housing colour usually indicates it. Both sides must be for the same voltage.
- 4Earth-contact positionGiven as a clock hour (for example 6 h, 9 h, 10 h) and listed on every product page. A plug and socket only mate when their positions match.
Let the selector narrow it down
Our plug and socket selector filters the whole catalogue by type, current, poles, voltage and IP rating, and greys out combinations that do not exist. When you have a short list, open the product pages to confirm the earth-contact position, then send us the part numbers for a quotation. If you are unsure whether two parts match, ask before ordering: we will check it against the catalogue for you.
Common questions
Why won't my plug fit the socket?
In the IEC 60309-2 system a plug and socket are coded by current, poles, voltage and earth-contact position. If any of these differ, they are designed not to fit.
What does the position in hours (6 h, 9 h) mean?
It is the clock position of the earth contact. The catalogue lists it for every part, and a plug and socket need the same position to connect.
How do I find a matching socket for my plug?
Use the plug and socket selector, or send us the plug's part number and we will check the catalogue and quote the matching socket.