Does this need a 16 amp supply?

[stuartpaul]

So, - let me try and get this right.

Stoady thinks I'll be all right on a 13 amp plug.
9Fingers reckons a 16 amp socket on a 16 amp circuit
Startrite say stick a 16 amp socket on a 13 amp circuit.

Stoady says that what startrite have said is 'dangerous' (and illegal?). I also don't like the idea of doing that so that's out.

Clearly the 13 amp plug appeals and I'll be having a go at that as soon as I get my mits on a blade and can spin the whole lot up.

If that fails then a 16 amp socket/circuit or send the bloody saw back!

I'm still miffed that their advertising material didn't allude to the fact that 16 amp required otherwise I wouldn't have bought the saw!! A fact that so far Startrite have refused to acknowledge.

I'm going to bob around the mediterranean for a couple of weeks so will come back to this on my return.

 

[9fingers]

Can I assume that you are a qualified spark? If so it will be useful here because as I often state, I am not qualified or up to speed with regs.

Well, er yes and no. I used to design and supervise electrical installations in factories in the 1960's but then moved on, but always in electrical engineering. Finished up as an international consultant until I retired 5 years ago. Used to work in crappy countries – three started wars after I left (Côte D'Ivoire, Lebanon and Pakistan) :shock: Built myself a nice double garage sized workshop for retirement, but have only now got to use it because I had a heart attack and my kidneys failed. For the rest of my life I have to spend 4½ hours in hospital every other day on dialysis.

That explains your technical contributions and I'm very sorry to hear of your kidney problem. That must a real PITA.

Bob

 

[Mike.C]

Stuart I hope that you do not mind me hyjacking this thread for a moment. Bob why don't 16amp plugs have fuses within the plug like a 13 amp does?

Cheers

Mike

Our 13 amp UK plugs are about the only plug in use (Europe and USA at least) that does have a fuse and relates to our use ring wiring.
'Normal' plugs/sockets are wired on radials which is the correct way to fit commando sockets of whatever rating.

Not a very good answer but a bit better than "because they don't" :lol:
Bob

No Bob that's a good enough answer. In other words if 90% of everyone else do not use them then I an happy enough to trust their judgment. What protects it then, just the MCB?

While on the subject. The sparky who installed the CU in my workshop put the 16 amp circuit (along with the lights) on the unprotected side. In other words it is not protected by the large main circuit breaker. I understand why the lights are there but I cannot understand why he did not protect the 16 amp saw?

Cheers

Mike

Has the sparky done this right?

Cheers

Mike

 

[9fingers]

Depends what you mean by unprotected.
If the 16a socket is truly unprotected then I think it is wrong but you are possibly confusing RCD protection with MCB protection??

Bob

 

[Mike.C]

Depends what you mean by unprotected.
If the 16a socket is truly unprotected then I think it is wrong but you are possibly confusing RCD protection with MCB protection??

Bob

Thanks for the fast reply Bob. Here is a photo of the CU

The 16 amp circuit is where it says table saw (right next to the lights) and as you can see it is not protected by the RCD. It has it's own MCB but not knowing anything about electrics, I have always thought that the greater protection comes from a RCD.
As I have said I understand why the lights are not on the RCD side, because if something happens and the RCD is tripped you have still got lights, but I cannot see why he has put the 16 amp over on that side too.

Of course it could be that the RCD is not as superior as I think it is and the MCB is just as good, but if that if that is the case why would you need RCD's?

Cheers

Mike

 

[9fingers]

MCB gives overcurrent protection and is essential in any circuit to protect downstream wiring not the appliance.

RCD is an 'optional' extra and gives protection against leakages to earth and will indicate a 'leaky circuit or appliance as well as offer protection against shock to users.

An RCD does not give any overload protection and must be followed by an MCB

On the downside, RCDs can sometimes suffer from nuisance tripping and maybe your spark opted to wire your saw circuit this way. alternatively, he may just have run out of spare ways on the protected busbar inside the CU?

Just to help maintain confusion, manufacturers are coming out with combined RCD/MCBs for each circuit at high prices to help protect their margins. These get used where the earth loop impedance is not considered low enough to trigger MCBs in the required time.

hth

Bob

 

[Mike.C]

Once again Bob thanks for putting my mind at ease.

Cheers

Mike

 

[Stoday]

The wiring regulations were updated in 2008 and now require a RCD if the circuit wiring is hidden underneath plaster.

The regulations are not retrospective, so no need to change existing wiring. However, if you are installing a new circuit and want to comply with the current regulations, you should either run new circuits on the surface, in conduit or use a RCD.