RCD for professional sunbed circuit installation (edited.)

[ericmark]

No it is not a commercial venture, we have purchased this second hand for our own use

I would think you will find because housed in a farm building the LABC will class it as a commercial venture if they find out. I have a problem with a garden room, which the LABC has classed as a granny flat and charge me £1000 a year council tax on it.

 

[spike47]

So can I start again ! .
There is no manufactures instalation instructions .

Lets assume I am not fitting the Sunbed , but need to purchase the items for a competent person to wire up the Bed, so the question will be what equipent will I need to purchase for the competent person to wire up this Sunbed.

I think all the info regarding the Bed is around this post, but will give some info has to the loading of the bed , the label says total load is 6700KW , it came with about 4 mtr of 6mm2 attached to a 63A isolator on the side of one of the panels , it has 40 tubes, it has a vent fan ( large ) at the top of it .

Supply will be via Main Fused Board in Farm Building ( Not the DNO board ) , which is about 15Mtr from where the bed will be located.

Have 16mm2 and 25mm2 tails and a 63A round isolator and a full roll of 6mm2 grey flat ! .


Spike

 

[ericmark]

There is no hard and fast rules, the skilled person has to decide what he wants, at the end he needs to sign the installation certificate which says he designed, installed and inspected and tested, so you can't design without signing the certificate, so he selects what he wants, no one can do that for him.

 

[spike47]

in which case you may need to apply to the local council for planning permission for change of use before making any significant investment

Change of use for what, it is going into our Gym room, it is for the family only, don't understand what you are saying

 

[flameport]

Lets assume I am not fitting the Sunbed , but need to purchase the items for a competent person to wire up the Bed,

If that were the case - which it obviously isn't - the competent person would be supplying all of the required materials.

You are not competent to install it, or design the circuit required for it, or do any of the other work that's required for it's installation.

The only safe option is to have an electrician install it.

 

[333rocky333]

Have a full roll of 6mm2 grey flat ! .


Spike

Which would be unsuitable to use if any of the wiring is concealed, as per post 2, if concealed then you must have 30ma RCD, to use your 100ma then the only cable really suitable to be buried or concealed is SWA

 

[spike47]

If that were the case - which it obviously isn't - the competent person would be supplying all of the required materials.

You are not competent to install it, or design the circuit required for it, or do any of the other work that's required for it's installation.

The only safe option is to have an electrician install it.

Yes it is the case, I don't know why you are not believing that this is, it is a second hand bed for us as a family to use, the Farm might be a commercial entity, but this is not connected to the Farm business, how could it be !, it is not making money for us !.

 

[spike47]

Which would be unsuitable to use if any of the wiring is concealed, as per post 2, if concealed then you must have 30ma RCD, to use your 100ma then the only cable really suitable to be buried or concealed is SWA

No cable is concealed !, it is clamped along the inside top of the wall of the building , load is 6700kw which is around 30A , I would of thought 6mm2 would of been ok ! .

 

[333rocky333]

No cable is concealed !, it is clamped along the inside top of the wall of the building , load is 6700kw which is around 30A , I would of thought 6mm2 would of been ok ! .

Surface is fine, i was only referring to the fact that Flat Twin concealed needs 30ma, a socket would also need 30ma, but you say it come with an isolater, so that solves that issue
I have not done the calcs so I cannot comment on the size, sorry

 

[JohnW2]

It ends up as heat, which is why sunbeds require substantial ventilation systems in the building they are used in.

Sure - as is very largely the case with the vast majority of electrical loads.

However, as I'm sure you understand, my point was that unless there is some explicit (intentional) 'heating involved', I would think (hope?!) that they must be incredibly (and, to my mind, surprisingly) inefficient - since, as I have said, if more than a tiny proportion of the 6.7 kW got turned into UV, it would probably be 'lethal'!

Kind Regards, John

 

[RF Lighting]

I think it’s time this thread was closed. The OP is no where near competent to be designing this installation, and how ever much we state this it is falling on deaf ears.

I would request that there are no more replies made other than telling the OP to engage the services of a competent electrician before someone ends up getting killed by some completely unsuitable lashed up twin and earth with inadequate protection.

 

[JohnW2]

I agree with AC capacitive and inductive linking can cause a leakage to earth even when with DC there would be no leakage ....

As I said, the 'inductive' case is a new one on me, so I need some education!

As I said, it's straightforward enough with capacitive coupling, since it is then possible for there to be a capacitive path to earth from the L of the supply - either through stray capacitance or, say, intentional filter capacitors etc. Even if (as will usually/often be the case) there is such capacitive coupling to earth from both L and N, the 'leakage current' through those paths will be much greater from the L than from the N (due to much larger pd across the capacitance), thereby leading to a net L-N current imbalance which, if large enough, will trip an RCD/RCBO.

However, in the case of the postulated 'inductive leakage', which an AC current flowing through an inductor will induce currents into any conductor within its field, I do not see how this can result in an imbalance of L-N currents in the supply to the inductor.

What am I missing?

Kind Regards, John

 

[spike47]

I think it’s time this thread was closed. The OP is no where near competent to be designing this installation, and how ever much we state this it is falling on deaf ears.

I would request that there are no more replies made other than telling the OP to engage the services of a competent electrician before someone ends up getting killed by some completely unsuitable lashed up twin and earth with inadequate protection.

OK let me say it now what is intend to be done , then that will be the end of this .

Wanting to fit a Sunbed it has 40 tubes and the load will be 6700kw, I have a 80A supply, that supply comes from a 3 phase 80A delay RCD, feeding a 80A Main fuse box pictured , that will feed the 63A RCD / 45A MCB , 6mm2 will be fitted to the 45A MCB, then about 10 Mtr along the wall to the Sunbed room , where a 63A Rotary isolator will be fitted on the wall, then the Sunbed will fit direct to the Rotary swtch .
E&O

Spike

 

[spike47]

Pic of main Fuse Board

 

[RF Lighting]

Why did you post here if you’re not going to listen to the advice we are giving? What a waste of all our time.