Type B or C RCBO

[La Poste]

Greetings.

Friend of mine has a fridge freezer and a standing freezer that need RCBO protection.

Both these appliances run off the same socket which is a separate radial so easy to protect as it will only be these two items on this one particular circuit.

I am not sure of the starting current of these appliances and so was wondering whether to fit a type B or type C 16 Amp RCBO.

What do you think?

Thanks a lot.

 

[telectrix]

I heard a rumour that cutting moulded plugs off invalidates your car insurance and stunts the growth of any veggies your growing in your garden. :biggrin:

what's car insurance? and we don't have plumbers or kitchen fitters growing in our garden.

 

[Octopus]

So its a new circuit, and thus its notifiable.

 

[La Poste]

No it's a spur off a radial.
An RCD'd spur off a radial.

 

[GLENNSPARK]

An RCD may be classed as either additional protection or to satisfy disconnection times....411.4.9.

If in the case of the OP if it was found that starting surges were a problem with a type B...and the Zs exceeded the maximum allowable for a type C OCPD would you rewire the circuit in a larger cable to bring it within the allowances for a type C..??,(or some other expensive fix?), when the regulations permit the RCD element of the device already installed to meet the requirements for disconnection times?
If you prefer the first option I'm glad I'm not one of your cutomers.

might only need an additional cpc ....parralleled up with the existing one in the cable..........

 

[GLENNSPARK]

I'd be inclined to go with glen sparks point and run in a radial but i would run it in a 4 or 6mm only reason is the cpc is larger in these so there fore the Zs readings should be lower i am a big fan of keeping the Zs as low as possible ,and for reasons eng54 has stated RCD's do fail , for certain circumstances you can install sockets without RCD protection

4mm??...bad cable to use nick mate as dont forget....still only a 1.5mm cpc..........

 

[La Poste]

Zs is 0.6 Ohms.

TN-S system, quite close to the transformer.

Surprisingly the voltage this afternoon at about 15:30 was 245 Volts.

 

[Octopus]

No it's a spur off a radial.
An RCD'd spur off a radial.

You've lost me now

 

[La Poste]

You can get RCD'd FCU, if you attached one to the end of a radial would it then be notifiable?

 

[GLENNSPARK]

if its an addition or an alteration to an existing circuit then its a minor works ......if in a garage (remote or attached as in this case) then it isn`t notifyable....

 

[La Poste]

if its an addition or an alteration to an existing circuit then its a minor works ......if in a garage (remote or attached as in this case) then it isn`t notifyable....

That's how I see it.

It's an extension of a radial which is fused at 32 Amps in the house.

 

[Engineer54]

An RCD may be classed as either additional protection or to satisfy disconnection times....411.4.9.

If in the case of the OP if it was found that starting surges were a problem with a type B...and the Zs exceeded the maximum allowable for a type C OCPD would you rewire the circuit in a larger cable to bring it within the allowances for a type C..??,(or some other expensive fix?), when the regulations permit the RCD element of the device already installed to meet the requirements for disconnection times?
If you prefer the first option I'm glad I'm not one of your cutomers.

That's all well and good wirepuller, until that RCD your now relying on for your disconnection times, decides to give-up the ghost!!

That's the point these day's, your all relying on this ''cure all'' 1667 ohms that an RCD provides instead of getting a decent Zs on your installation circuits.. You can look at it anyway you wish, on a TN supplies an RCD should always be looked on as ''Additional'' Protection NOT your only means of protection!! That type of protection should be limited to a UK TT system, and even that, doesn't sit too well with me, but i can live with it ...to a point....lol!!!

 

[Octopus]

You can get RCD'd FCU, if you attached one to the end of a radial would it then be notifiable?

I was wondering how we got from a question about which RCBO's to use, to using an existing circuit and adding a RCD FCU!!

 

[La Poste]

Well why is it that we can add a FCU to an existing radial and it is classed as a non notifiable extension.

And yet when we add a small DB to the end of a radial it then in your opinion becomes notifiable.

So its a new circuit, and thus its notifiable.

Please explain this to me.

 

[Octopus]

That's how I see it.

It's an extension of a radial which is fused at 32 Amps in the house.

Out of interest what is on the main board? Is it RCD'ed

 

[La Poste]

This particular radial is not, it's fused at 32 Amps, but the rest of the house board is.