How much does it cost to install a three-phase socket for a machine in Spain?

Three-phase socket for a machine: cost

What a three-phase socket costs depends on the distance to the fuse board and the power of the machine. The guide reference is 150 to 500 euros per socket installed: the lower end if the board is close and there is conduit, the upper end if a long or high power new line has to be run.

What a power socket includes

• An industrial socket, CETAC type to standard UNE-EN 60309, with the number of poles and amperage the machine needs.
• Cable sized for the power and the distance.
• Its own protection in the board: MCB and RCD.
• Conduit or cable tray, tough enough for a workshop or warehouse.

What you need to know first

• The power and current of the machine, shown on its rating plate.
• Whether it is three-phase with or without neutral, to choose the right socket.
• The type of start: large motors may need a soft starter or variable speed drive to avoid current spikes.
• Whether your supply is three-phase and has power available. If not, a change of supply or a power increase will have to be looked at.

Motors and starting

Three-phase motors draw a current spike when they start. For compressors, saws or pumps of a certain size it is worth checking the protection and considering a soft starter or a variable frequency drive, which reduces that spike and lets you control the speed. ITC-BT-47 regulates motor installations.

Common mistakes

• Using extension leads or household sockets for three-phase machines.
• Connecting the machine without its own protection, hanging off another line.
• Reversing the phase order, so the motor turns the wrong way.
• Not labelling the socket’s circuit in the board.

If your premises are single-phase

Many small premises have a single-phase supply. If the machine is three-phase, the supply has to be converted to three-phase, with work on the individual riser cable and a new boletín (electrical certificate), or a single-phase version of the equipment must be found. We assess it before you buy the machine.

When to call an electrician

Call if you are installing new machinery in a workshop, warehouse or commercial kitchen. In Seville, Spain, we handle machinery connection, solve starting issues with motors and variable speed drives and design complete warehouse electrics.