Outdoor Cabin Feed Help

[richo106]

Hi

We are having a new log cabin installed at my work place and after some advice. Will be getting electrician to come and quote etc but would like to know what it entails first if possible.

Currently we have one cabin (with lights, sockets, heater) this is fed via a 2 way garage DB - 40A, 63A RCD main breaker - 15meter run SWA. This 2 way DB is fed from a main DB in another room fed from a 40A MCB also. Im guessing the cable sizes are 10mm maybe 6mm. My question is can i feed another log cabin 50meters away (needing lights, sockets, heater) using SWA and another 40A MCB in the 2 way DB?

What would people suggest?

All advice info appreciated

Thanks

 

[Pete999]

No, not a good idea lots of things to consider: loading of new building , Volt drop and Installation method, wait for the Sparkie's recommendations, and if he is any good you should be OK, or have you been coerced by your firm to do this job yourself?

 

[richo106]

No, not a good idea lots of things to consider: loading of new building , Volt drop and Installation method

Thank you, would you suggest taking a feed back to the main DB then?

 

[Pete999]

Thank you, would you suggest taking a feed back to the main DB then?

Yep an entirely new supply from start to finish including the correct earthing arrangement.

 

[richo106]

Yep an entirely new supply from start to finish including the correct earthing arrangement.

ok thanks, without calcs etc would 10mm on 40A MCB be suitable?

 

[richo106]

would it be possible to gland the SWA into a weatherproof box, potentially join to a 10mm T&E so this could be routed easier through the building to the DB?

 

[GMES]

Hi Richo , unfortunately you won't get a step by step guide from the members, you appear to be asking questions that lead me to think you're going to do the work yourself, Pete as already given you the best advice.

 

[richo106]

Hi Richo , unfortunately you won't get a step by step guide from the members, you appear to be asking questions that lead me to think you're going to do the work yourself, Pete as already given you the best advice.

Yes I understand that completely, just trying to gauge the scale of the job and what disruption there will be etc

 

[MJPD29]

I wouldnt worry too much I'm sure the electrician will be able to design it properly and decide on cable routes

 

[GMES]

It's fine pal, but if as you say it's a new cabin and new supply then there won't be any disruption.

 

[GMES]

@richo106
I'm slightly confused, you say you're getting an electrician to do some work at your workplace but after having a look at your profile page and previous threads it would appear you are an electrician.
Can you just clarify whether you are a customer or the contractor.

 

[richo106]

@richo106
I'm slightly confused, you say you're getting an electrician to do some work at your workplace but after having a look at your profile page and previous threads it would appear you are an electrician.
Can you just clarify whether you are a customer or the contractor.

For this job a customer, I used to be a contractor electrician where I did industrial installations but now a facilities manager in charge of getting people in to carry out the work. Hence why I ask a lot of questions relating to domestic work for work on my own or family’s houses as that is the only practible work I do now. Hope that clears it up and sorry to cause any confusion

 

[Pete999]

ok thanks, without calcs etc would 10mm on 40A MCB be suitable?

It would be wrong to say cable calcs are a prerequisite when designing an installation, guessing is tantamount to being a Cowboy.

 

[Yozza19]

To satisfy volt drop for 40a at 75m you are looking at 16mm at least Possable a 25mm
Also hope you are taking earthing arrangements into account aswell

 

[GeorgeCooke]

Apart from other considerations you have two 40amp breakers in line and are proposing a third. Completely wrong as there will be no discrimination and a fault in the new cabin will cause all three to trip.

 

[Toneyz]

An assessment of the new load (allowing for diversity) upon the existing needs to be done first. As long as this and other checks have been done and there is suitable space in the existing D.B. the principle should be the same albeit the distance is greater, therefore, the cable supply is bigger.

 

[richo106]

Has anyone used any other methods of routing SWA cable outdoors?

Ive only ever known used burying cable 600 deep, sand base, tape etc.

But my boss is not happy with the price, especially for the ground works side, and wants me to explore other ways.

 

[DPG]

Catenary wire would be cheaper. But as above, the sparky doing the job will decide what's possible.

 

[GMES]

Also the other option is traywork depending on route and aeshetics of the building.