commercial installs

[atm84]

May seem like a stupid question but I have come across a number of commercial installs such as offices, sports centres etc where the installer has used steel conduit which is embedded into the building fabric. As a result rcd's/rcbo's are not generally required on the lighting circuits.

I'm trying to work out why they wouldn't just plaster over the cables and fit an RCD or rcbo to the circuit. Surely it would be cheaper than using steel conduit everywhere.

The only reasoning that I can think is that if that there would be much less disruption caused if someone drilled through a cable and also by not fitting an RCD/rcbo it alleviates the problem of nuisance tripping.

 

[ipf]

It's all about working to specification. The ideal installation is to be done in steel conduit, embedded. Can't get much better.

 

[atm84]

Why though?

 

[Clive P]

Hi,

Architects specification.

Regards.

 

[ipf]

Public or important buildings in many instances. Look at hospitals, fire stations, SPORTS CENTRES, etc. As few problems as possible and the safest installation are required.

 

[driverman]

As it's a commercial building RCD's RCBO's are not reqd. Assuming all other criteria met. Or have i got this wrong?

 

[ipf]

As it's a commercial building RCD's RCBO's are not reqd. Assuming all other criteria met. Or have i got this wrong?

Most specifications will insist on RCD protection for general socket outlets, at least.

 

[atm84]

Driver man that's correct however like Ipaf says socket outlets used for portable appliances up to 20amps require RCD protection. Lighting circuits and such like are omitted from RCD protection if the installation is under the control of skilled and competent persons ie a maintenance guy. My point is why not just fit an RCD and not have to bother installing conduit.?

 

[atm84]

Hi,

Architects specification.

Regards.

What do architects know? They usually don't know the difference between a plug and a socket. The amount of times I had heard then say 'I want two plugs fitting over there', 'oh you mean two sockets' I say.

 

[Clive P]

Hi,

I have worked with some very good Architects and not trying to question your thoughts but any good spark would know the answer to the question you are posting, and would regard that type of installation to be one of the best for a lot of good reasons.

Regards.

 

[snowhead]

To the O.P
In a house then why not just clip flex on top of the plaster?
Why bother hiding it.

Why do they use doors costing over £1k in some commercial buildings when a B&Q £30 special would still fill the hole?

 

[Lukethoma1985]

Saves nuisance tripping due to the rcd

 

[Plonker 3]

Nuisance tripping only occurs on a shared RCD board. RCBOS will only trip when there is a fault on the circuit.

 

[atm84]

Hi,

I have worked with some very good Architects and not trying to question your thoughts but any good spark would know the answer to the question you are posting, and would regard that type of installation to be one of the best for a lot of good reasons.

Regards.

Must make me a bad spark then.

 

[atm84]

Hi,

I have worked with some very good Architects and not trying to question your thoughts but any good spark would know the answer to the question you are posting, and would regard that type of installation to be one of the best for a lot of good reasons.

Regards.

Not best price though ad I am sure you are aware In this day the cost of an installation is one of the major factors that determines the type of install. I'm not asking of justification I was looking for reasoning why steel conduit may be better not just cos some architect specs it. I was looking for reasons why anyone would spec it.
Thanks for your help guys.

 

[atm84]

(null)

Not quite the same is it. Now you are being silly aren't you.

Flex would be visible wouldn't it you silly boy. Customers don't want to see cable clipped surface.

In OP the cabling is hidden, nobody would see it I'm asking what benefits would there be if steel conduit was used.

PS I'm sure the fire regs may pay an important factor regarding the type of door.

 

[ipf]

Nuisance tripping only occurs on a shared RCD board. RCBOS will only trip when there is a fault on the circuit.

Could be even more of a nuisance though:thinking2:

 

[Lou7]

Conduit is rewireable.

 

[Lukethoma1985]

I know, what i mean is if theres a faulty washer or dryer etc it wont knock that circuit off just for a faulty appliance

 

[atm84]

Conduit is rewireable.

Cheers Lou