Fused Spur for woodworking machinery

[manglehead]

Hi All,

I am having an out building fitted with a ring main and lighting running from a CU in the outbuilding which in turn will be supplied by 6mm cable in conduit from the CU in the house. i am doing the donkey work fitting the main conduiting and sockets and getting an electrician to do all of the proper connection work. My main query is about adding woodwork machinery to the ring main? I have a large band saw which has a 8.6 A rating on the motor? which the manufacture suggests a 20 AMp protection for it. i also have a drill press which i am not sure on the amp rating. Is it best to have fixed fused spurs for each machine with adequate amp coverage running from the ring main to cover this usage? i am also not sure on the total load for the CU. I will be have at least 6 double sockets plus the spurs and 2 sets of double fluorescents in the garage, with one exterior masterseal double socket too. Any tips and suggestions?

 

[flameport]

For any kind of complete answer, you must ask the electrician who will be doing the 'proper connection work'.

However, from the information provided:

8.6A for the saw is probably the current when the motor is running. The starting current will be significantly higher.

For the drill (and anything else), the motor rating must be known before it can be connected to any supply.

The fluorescent lighting must be HF types, and a 'ring main' is probably the wrong type of circuit for this installation.

 

[roosteruk]

I would run seperate 2.5mm radials from the CU in the garage on their own breakers. These could be terminated near to the machinery via isolators. (Button, or lever.)

 

[manglehead]

can i ask why a ring main wouldn't be suitable for this type of installation?

regarding the separate breakers do you mean have a 4 way in the CU one for lights, one for sockets and one each for the machines?

Thanks for your help so far.

 

[roosteruk]

can i ask why a ring main wouldn't be suitable for this type of installation?

regarding the separate breakers do you mean have a 4 way in the CU one for lights, one for sockets and one each for the machines?

Thanks for your help so far.

Thats what I did in my garage.

I had a 6 way. I ran a 32A for a ring main and 6A for the lighting.
A seperate 16A for my bench drill.
A seperate 16A for my Welder. (I also used a blue 16A sockets and Plug on the Welder)
The last one feeds an outside RCD socket.

I can't see why a seperate ring on 32A cannot be used, supplying the isolating switches, I had the stuff available for running radials and preferred it that way.

 

[Stoday]

can i ask why a ring main wouldn't be suitable for this type of installation?

The ring circuit in the outbuilding is protected with a 32A MCB. The 6mm feed to the outbuilding ought to be protected with a 32A MCB to avoid overload.

You can't discriminate between the two 32A MCBs; either could trip on a fault or overload. Such a situation does not comply with the wiring regulations.

Best to avoid the situation by a larger feed cable with a 45A MCB (say) or 20A radials instead of a ring circuit.