32a busbar feeding floorboxes

[Rich.]

Should the busbar be fed via an rcbo or not

 

[telectrix]

too little info.

 

[Rich.]

It's a 32 A busbar single phase feeding computers via floorboxes

 

[KINKY]

Try and squeeze some more info out??????

 

[Engineer54]

Are you talking about An RCBO supplying a plug-in bus bar strip, located under raised floors feeding recessed floor box outlets ???

 

[Rich.]

Yes that's the one I was after

 

[Engineer54]

Should the busbar be fed via an rcbo or not

Well if that's the case, it very much depends on the loads being supplied, and there leakage currents. If were talking about normal PC type loads the 32A rating seems a little on the high side. If your talking about commercial type systems, we need a little more information on those loads... Normally those floor outlets only supply general loads in computer suites, so there shouldn't be any problem supplying them from a RCBO protected circuit. What size cable is supplying these plug-in bus bar strips, are they being supplied via a radial circuit(s) or connect to a Ring circuit??

 

[Rich.]

Supplied by 6 mm swa radial

 

[Engineer54]

Really can't see a problem, with this install.
Why are you concerned about these floor box outlets being protected by an RCBO??

 

[Rich.]

It's just every other install I've done with the same setup they've always been rcbo's

 

[Engineer54]

I am Sorry Rich, i thought you were concerned about this set up being protected by an RCBO...lol!!!

Yes, normally any under floor or floor mounted or recessed raised floor outlets should be RCD protected. ....Cleaners, especially those from far off foreign shores have a nasty habit of sploshing soapy water everywhere and at everything...lol!!!!

 

[bugsy]

Don't normally put RCBO;s on floor track as a fault on one desk takes out all the work stations connected to that run

 

[malcolmsanford]

We do quite a lot power track under floating floors out here. Our normal installation uses the 63 amp type using various tap of section. We normally don't use RCBO's to protect the track as source, normally it will be a double pole MCB.

We use a normally fused tap off points, as you can not use the unfused type on a 63amp track, you can on a 32amp one though, but only if the tap off is under 3 mteres. All the Tap off points are pre measured 3 mt 5 mt etc.

We normally fit RCD socket oulets rather than protecting the track, as was said earlier if you get one fault on a tap off it will take out the whole track, which really annoys the client.

Also we have quite a few items such as large inkjet printers, commercial shredders etc on non RCD protection.

 

[davelerave]

you couldn't protect the 32amp with 30ma -if you go by the recommendations of max 4 workstations at up to 3.5ma each

the loading is only up a bout 2kw unless the drink is confusing me again



keep protection local as possible anyhwow if you have to rcd IT equipment

 

[Wully]

I remember years ago all underfloor busbar trunking / tap-offs to floor boxes were always fed from MCB's. The main issue related to earth leakage from the old CRT monitors.

With the current regs I would always supply via RCBO as the big problem from a design side of things is users plugging in phone chargers, desk fans and I've seen hair straighteners!

 

[IQ Electrical]

I remember years ago all underfloor busbar trunking / tap-offs to floor boxes were always fed from MCB's. The main issue related to earth leakage from the old CRT monitors.

With the current regs I would always supply via RCBO as the big problem from a design side of things is users plugging in phone chargers, desk fans and I've seen hair straighteners!

I'll go with Malcolms design here, you don't compromise half a computer suite on the basis that someone might plug in some hair straighteners, phone chargers or a desk fan (which are all probably class II anyway).