Restaurants / Pubs Outdoor heating.

[FUSEServices]

I have been asked to quote to install 6 x 1.8kW heaters to a wooden pergola with a perspex roof. It's on decking and there is a TN-C-S earth provided. There are obvious things to consider about the heat etc, but I'm more concerned about the electrical installation. It is 12m long and 4m wide and he wants a heater at each corner and in the middle on the long side. The heaters have a 13A plug and the instructions specify that it's kept as a plug and socket arrangement. They have remote controls.

The quote he has had from a "cheaper" company involved fitting an RCBO in the main board, running a 10mm cable to the first position then in and out of a wiska box, then taking a 2.5mm feed to each socket (doubles) and continuing like this as a giant radial. I can't technically fault it, as no more than 26A can be drawn, so the 2.5 cable is fine but I know the sockets will burn out eventually, seen it so many times in a domestic situation where the "knowledgeable" kitchen fitter has supplied a cooker and a washer off a 2g socket. the run from board to first point is 15m.

I Would take a 10mm 3c SWA cable from the merlin board with a 63A breaker around the outside wall to the point of the first heater and fit an ip rated enclosure with a 6w RCD consumer unit in, and run 6 x 16A circuits on 2.5mm either conduit or SWA and have a single socket at each heater point. This is a lot more expensive. Am I going too far?

What do you guys think?

 

[pc1966]

Lollipop?

Run a ring in 4mm around for single 13A sockets and then feed that via big enough junction box with the single large 10mm cable from the CU from a 50A MCB. They are heaters so minimal inrush (small increase as elements heat).

Of maybe easier to do two rings in 2.5mm and fed from two 32A MCBs in a small CU, again fed by 50/63A feed.

 

[telectrix]

10mm to a 2 way CU. 2 x 4mm radials, each on a 32A MCB or RCBO as required. 3 heaters on each radial.

 

[Darkwood]

All fine until they are still cold and he adds a few more heaters lol

I would play caution and have a submains and run 6 radials to 6 single sockets or spurs, you can rcbo or rcd outlets depending on the cable runs ... of course you will be undercut pricing in this method but that is where the charm comes in and giving that customer more confidence in your design and its flexibility, who would want to lose half or all their heaters because damp has settled on the element overnight and tripped the rcd/rcbo

 

[telectrix]

but is RCD protection required as long as the heaters aren't plugged into socket outlets.?

 

[FatAlan]

Cheaper to serve a free hot toddy with every drink!

 

[pc1966]

The OP has said the instructions say keep plug & socket.

Shame, as on FCU could avoid the RCD issue but with sockets in a pub, even if intended for the heaters only, I would not trust some muppet to use one for something else, extension lead, fairy lights at Xmas, etc.

 

[telectrix]

never would have had the problem before blair banned smoking in pubs.

 

[littlespark]

Any plug and socket in a public area can be open to misuse... (unplugging the heaters etc)

cut off the plugs and use unswitched fused units on separate radials from a board in an external enclosure.

you can explain that over time, a double socket with 2 heaters will fail over time... the undocumented 20A limit of a double skt.

 

[telectrix]

Any plug and socket in a public area can be open to misuse... (unplugging the heaters etc)

cut off the plugs and use unswitched fused units on separate radials from a board in an external enclosure.

you can explain that over time, a double socket with 2 heaters will fail over time... the undocumented 20A limit of a double skt.

that's what I was getting at. ditch plug/socket/s and RCD/s not required.

 

[Darkwood]

never would have had the problem before blair banned smoking in pubs.

And the funeral parlours would be busier too and who needs staff health protection anyway ? they should just get a job where there is no smoke... oh wait, you could smoke in most work places too ?.... Damn you Blair for putting peoples health first ??

 

[FUSEServices]

Thanks all. It’s a Mediterranean restaurant with outdoor eating as we can’t eat indoors.

I think it’s defo an enclosure with RCD Main switch and 2 x 32A breakers feeding 2 x 4mm radials with single switches sockets on the end.

Keeping with the manufacture’s instructions to avoid issues should he want to remove them and take them in.

Thanks for taking the time to give your opinions.