Advice on 16A mains sockets

[ade_tumu]

I note many single phase machines require a 16A plug. I've seen a number of connectors with a 16A plug at one end going to a standard 13A plug at the other (presumably fitted with a 16A fuse). How can I tell if my wiring / mains sockets are up to taking 16A current? Is there anything dangerous about using these connectors? Thanks.

 

[RogerS]

As electric motors or machines get larger in size then the current that they draw (especially on start-up) can exceed the 13A that 13A plugs are fused with and so the fuse blows. There is a grey area - depending on the size and loading on the machine -where sometimes it might blow..sometimes the motor might start up OK. I'll give you an example. My spindle moulder can be fitted with anything from a light aluminium block to a huge lump of steel. The starting current needed to get the motor turning with that lump of steel will blow a 13A fuse for certain. Which is why those machines have 16A plugs on them.

The 13A plug in your adapter (with the 16A socket ..you say plug but I think you mean a socket) might simply be just that...an adapter to let the owner plug their machine into a 13Amp socket. Chances are though that whoever made the adapter up, got a bit of wire and wrapped in around the terminals where the fuse should go. Not a good idea.

Ideally you'd run a dedicated cable directly from your consumer unit to a 16A socket. Called a radial cable. However, the sizing of the cable depends on factors such as length of cable etc.

Get an electrician in.

 

[Chems]

Sometimes it depends on the socket your using, my 3hp table saw comes with a 16amp plug or a 13amp plug sometimes dependant on where you buy it. When I first had it I had it connected via a poorly wired ring main and it would blow the fuse every 10th start up or so. But once I rewired the plugs properly it very rarely blows a fuse, probably once every few months.

 

[Stoday]

Much better to install a 20A mcb in the consumer unit and run a 2.5mm² cable to as many 16A sockets as you need. The regulations allow this, providing the after diversity demand is 20A or less. That would normally apply to a workshop with only one man working in it, because he can only operate one machine (plus dust extractor) at a time. The circuit can supply 4.3 kVA before overloading.

 

[DaveyP]

diversity

Diversity can be your friend

However.... in theory the cable (depending upon the unknown length and also unknown method of installation needs to de-rated

Which (unless of course it was my own workshop..lol :wink: ) would advise 4mm.

Anyone suffering from mcb's tripping on machine start up could look at changing the relevant mcb for a type 'C' which whilst still offering the same overload protection is a bit more forgiving on inrush (start up) currents.

 

[angelboy]

I have a Jet contractor saw which is supposed to need a 16a circuit.

It works fine without.

 

[shipbadger]

The 16A socket to 13A plug you see on sale are I think mainly intended for caravan/motor caravan owners to connect their extension leads to the house/garage supply when battery charging at home, the charger being mounted on the vehicle. The 16A connector is the standard for recreational vehicles and used on many sites, though often only providing a max of 10A. Some years ago a few sites had the standard 13A socket but I suspect these have all been changed nowadays. I have an adapter specifically for this purpose.

Tony Comber