16 amp upgrade

[chippy mark]

I have ordered a new table saw which requires a 16 amp supply, my workshop has a two way garage consumer unit with one breaker for the sockets and one for the lights, can I connect another two way garage consumer unit to the existing one and use the 16 amp breaker from that? or do I need to replace the consumer unit completely?

 

[Blister]

Does the feed come from your house ?

If so what is the amps from the house consumer unit ?

13 amp and 16 amp wiring are different sizes as in you cant get 16 amps down a 13 amp cable safely

 

[chippy mark]

Yes the feed comes from the house it's on a 40 amp breaker with a thick cable ( I'm no sparkie ) supplying the workshop

 

[Digit]

Bit of a guess here mark as you don't specify the actual cable spec, but assuming that the cable is upto snuff, yes you can install another unit along side. If you can measure the conductors for us, power off at the supply end please, we could give you a more definitive answer.

Roy.

 

[chippy mark]

Well without having to take the consumer unit apart I have measured the outer flat grey cable which is 12-13 mm at the widest part, I think it is as thick as cooker cable

 

[Digit]

Sounds like a 6mm, now someone is gonna go all pedantic and tell me that the current rating is dependent on temp, enclosure, length etc, but nominally the cable is rated 32 A, so you should be in the clear.

Roy.

 

[RogerS]

..... so you should be in the clear.

Roy.

Ahem...apart from Part P

 

[Digit]

Part P? What's that? :lol:

Roy.

 

[DeanN]

My table saw has a 16amp plug fitted to it, but I'm running it off a 13amp supply until I can afford to upgrade the electrics. I've had no problems so far.

 

[Digit]

There is a tolerance in motor consumption, don't think because the info says X amps that the motor will indeed draw X amps! Some will draw more, and some less.
But from the point of view of the fuse/MCB it's normally the start up current that causes problems rather than the running cuurent.
Dust in the bearings, a large heavy blade, a tight belt, frequent starts, restarting before the motor has ceased spinning, will all cause a higher start up current. My 10 in SIP eats 13 Amp fuses, and thus is on a 16 Amp supply, other members on this forum have the same model running happily on a 13 Amp plug.

Roy.

 

[chippy mark]

The saw I'm getting is a Axminster AW10BSB2, it has a 16 amp plug fitted I will try to run it on a 13 amp socket via an adapter and see how it goes, my metabo spindle moulder has the same size motor which runs ok on 13 amp

 

[munkypuzel]

Hi Mark,

I used to have that Axminster saw and it worked faultlessly off of a 13amp plug top, even in the freezing cold conditions! (garage)

Cheers
Mark

 

[siggy_7]

What's your intended maximum load? If the cable outer diameter is only 12-13mm and it's armoured, then I'm not too sure whether it's substantial enough for big current draws. This thread contains info on cable outer diameter for BS 5647 SWA cable:

http://www.electriciansforums.co.uk...installations/11898-armoured-cable-sizes.html

The cable should be of a size such that the maximum combined loads before a breaker trips don't exceed the capacity of the cable, i.e. the lower of the breaker coming from the house (assuming the supply is coming from a breaker on the house consumer unit) or the total of all the breakers in the workshop. If your current arrangement passed building regs and there's a 40A breaker in the house, you may not have a problem, but that depends what's in the garage consumer unit.

Regarding Part P, detached garages and sheds are not notifiable works under Part P, so providing you don't have to upgrade the cable feeding the garage I don't think there are any implications there, providing your work meets the required standards of a hypothetical random check.

 

[chippy mark]

The supply cable is not armoured it's normal grey twin & earth the same as cooker cable

 

[RogerS]

.......

Regarding Part P, detached garages and sheds are not notifiable works under Part P,....

Are you sure?

This from the IET website

Part P applies to electrical installations located in outbuildings such as detached garages, sheds and greenhouses.

and confirmed on many other sites. Even to the extent of adding new sockets. Here for instance ...page 9

 

[angelboy]

The saw I'm getting is a Axminster AW10BSB2, it has a 16 amp plug fitted I will try to run it on a 13 amp socket via an adapter and see how it goes, my metabo spindle moulder has the same size motor which runs ok on 13 amp

I'm running a Jet Contractor saw with a 110v 16 amp plug into a standard 13amp 110v transformer then straight into the mains socket. Works fine!

Plug it in and give it go!

 

[jack55]

I have the AW10BSB2 it does not need a 16amp supply, the AW12BSB2 the 12" saw does. It comes with a 16amp plug but you can swop it over for a 13amp. If you read the catalogue it does state that its the 12" saw that needs the 16 amp supply.

 

[9fingers]

There are no simple rules as to whether a 16amp supply is needed. It varies from machine to machine and from different electrical installations and with temperature.

Before embarking on any significant expense, I suggest you try the machine (maybe via an adaptor) on a 13amp supply and if it works OK continue to use it and only move to 16amp if you are getting an annoying level of fuse blowing in the 13amp plug.

Earlier in the thread someone said that the cable for a 16amp supply had to be greater than that for a 13amp supply. This is WRONG.
a 13 amp supply ring needs 2.5mm2 cable and a 16amp radial can be run via a 1.5mm2 cable. both are limited by length but unlikely to be a problem in a home workshop.


Bob

 

[OLD]

What i have done is convert the socket feed into a ring main so it could deliver 32amp but fit a 20amp mcb then fit a 16amp socket to the ring main this set up has worked fine for 5years. This way you do not have to fit a new consumer box.

 

[misterfish]

Looking at the Farnell (CPC) website 6mm twin + earth is about 13mm wide by just under 7mm thick. This is rated for 46 amps which would tie up with the 40 amp breaker in the house. http://cpc.farnell.com/1/1/59507-cable- ... power.html

My workshop has a 50 amp breaker in the house with 10mm armoured cable to a consumer unit in the workshop with 2 x 6 amp lighting breakers, 2 x 32 amp ring circuit breakers and a dedicated 16 amp (type C) breaker dedicated to the table saw.

If i was in your positionI'd look to replacing the consumer unit in the workshop with a larger version, but no reason why you couldn't add a second 'garage' type unit.

Misterfish