Colour shows the voltage
| Colour | Operating voltage (50/60 Hz) | Typical use |
|---|---|---|
| Yellow | 100 to 130 V | 110 V site tools and portable lighting |
| Blue | 200 to 250 V | single-phase equipment, site distribution, camping and marine supplies |
| Red | 380 to 480 V | three-phase motors, welders, compressors, site boards |
| Black | 500 to 690 V | higher-voltage industrial equipment |
| Violet | extra-low voltage (up to about 50 V) | special low-voltage circuits |
| Green | frequencies above 60 Hz (up to 500 Hz) | special high-frequency supplies |
The earth pin position (clock system)
Looking at the socket face, the position of the earth contact is read like an hour on a clock. Each position stands for a voltage and frequency combination, so two plugs of the same colour but different earth positions will not mate. The 6 h position is the most common: it covers the standard blue single-phase and red three-phase supplies. Other positions are used for special voltages and frequencies, so when you replace a plug or socket, read the clock position from the old one or its marking.
Current ratings and sizes
IEC 60309 plugs and sockets come in 16 A, 32 A, 63 A and 125 A. Each rating has its own physical size, so a 32 A plug does not fit a 16 A socket. The socket must be protected by a breaker no larger than its rating, and the flexible cable sized for the load and its length; our cable size and breaker size tools help with both.
Number of poles
| Pins | Configuration | Used for |
|---|---|---|
| 3 pins | 2P+E (phase, neutral, earth) | single-phase loads |
| 4 pins | 3P+E | three-phase loads without neutral, most motors |
| 5 pins | 3P+N+E | three-phase loads that also need a neutral, mixed loads, distribution boards |
A 4-pin plug does not fit a 5-pin socket. Choose 5-pin sockets on a site board when you are not sure what will be plugged in, and fit adaptors or leads only if they are made for it.
IP44 or IP67?
IP44 (splash-proof) types have a spring lid and suit indoor workshops and covered areas. IP67 (watertight) types have a sealed screw ring or lid and suit outdoor, wash-down and dusty areas; the seal only works when the plug is fully engaged and the ring tightened, or the lid closed. Some ranges are marked IP66/IP67. In Saudi outdoor conditions, sun and dust also matter, so choose UV-stabilised housings.
Interlocked sockets and mounting types
- Interlocked sockets have a switch that must be off before the plug can be inserted or removed, so the contacts never make or break under load. Use them for motors, welders and higher currents; many come in a box with a fuse or breaker.
- Mobile (cable) types: plugs and connectors (female, on the cable) for extension leads and equipment.
- Fixed types: surface-mounted sockets on walls and columns, and panel-mounted sockets and appliance inlets (straight or angled) on boards and machines.
What to send us for a quotation
For each item: plug, connector, surface socket, panel socket or inlet; current (16, 32, 63 or 125 A); number of pins; voltage or colour; earth position if not 6 h; IP44 or IP67; and whether the socket must be interlocked or switched. For site distribution boards, send the list of outlets and the incoming supply, and we quote the complete assembly with cable and glands.
Common questions
What is the difference between a blue and a red industrial plug?
Blue is for 200 to 250 V, normally single-phase. Red is for 380 to 480 V three-phase. They are shaped differently so they cannot be mixed.
Is a 5-pin plug the same as a 4-pin?
No. A 4-pin plug is 3P+E and a 5-pin plug is 3P+N+E. They do not fit each other's sockets; use the one that matches the load.
What does an interlocked socket do?
It prevents the plug from being inserted or removed while the socket is switched on, so the plug never connects or disconnects under load.
Need these items? Send your list or a nameplate photo; your quotation arrives within 24 hours.
This guide is general information. Final selection must follow the project design, the applicable standards and the maker's data.