How many computers to 1 30ma rcd

[simpson93]

Hello all, just wondering in an office with lots of it equipment how many computers would you put to one 30ma circuit?

 

[Guest77]

Average pc can leak 2.5ma, hense my opinion regarding 4 max, imagine 14 PCs on one RCBO which when ramp tested trips at 22ma lol

 

[Darkwood]

I used to do classrooms and I fitted RCBO's from the Schneider SI range which filter and ignore the designed leakage and only trips under normal fault earth leakage conditions. This allows more computers than a standard Earth leakage device and reduces the number of circuits required.

As you are limited anyway to the computers on your circuit - does it really make sense to wire rings, would not radials be a cheaper solution here.

 

[cliffed]

Agree,radials seem a good idea

 

[Pete999]

I used to do classrooms and I fitted RCBO's from the Schneider SI range which filter and ignore the designed leakage and only trips under normal fault earth leakage conditions. This allows more computers than a standard Earth leakage device and reduces the number of circuits required.

As you are limited anyway to the computers on your circuit - does it really make sense to wire rings, would not radials be a cheaper solution here.

Trouble with a radial high integrity circuit you need to use a duplicate cpc bit difficult if you use Tin with cpc, not a problem with a RFC

 

[Guest77]

Rings or radials are irrelevent, the fact is the op is planning on 14 PCs connecting to 7 twin socket outlets, it is a mistake and he won't listen, we all know what is needed, we know what to suggest but he won't listen, so god help his customer, simple maths but still no joy in persuading him, lots of help but no cigar at the end of it, I give up.

 

[Darkwood]

Trouble with a radial high integrity circuit you need to use a duplicate cpc bit difficult if you use Tin with cpc, not a problem with a RFC

Yes but only issue if not contained then its a 4mm earth to last socket for the return but if in trunking etc its a doddle... I don't see this as a problem IMHO, although certain set-up won't be as suitable as others agreed.

 

[shanky887614]

Trouble with a radial high integrity circuit you need to use a duplicate cpc bit difficult if you use Tin with cpc, not a problem with a RFC

i didnt realise you guys tin the ends of the cable.

does it help with computer's?

 

[telectrix]

no but it helps with soldering a joint.but then, i prefer to smoke them.

 

[Guest77]

Don't add 14 PCs to one circuit with one RCBO on it

 

[VoltzElectrical]

I was involved with one installation in a school, installation and testing only mind you.

We put ( I think) 8 PCs on each ring with the earthing split across each terminal (i.e. not doubled up)

I always understood to allow for up to 10mA earth leakage per PC.

Just my two penneth for what it's (NOT) worth!

 

[Pete999]

Rings or radials are irrelevent, the fact is the op is planning on 14 PCs connecting to 7 twin socket outlets, it is a mistake and he won't listen, we all know what is needed, we know what to suggest but he won't listen, so god help his customer, simple maths but still no joy in persuading him, lots of help but no cigar at the end of it, I give up.

Suppose you can lead a horse to water but you can't make him drink it, think you are right :leaving::leaving::leaving::leaving:

 

[Darkwood]

I was involved with one installation in a school, installation and testing only mind you.

We put ( I think) 8 PCs on each ring with the earthing split across each terminal (i.e. not doubled up)

I always understood to allow for up to 10mA earth leakage per PC.



Just my two penneth for what it's (NOT) worth!

10mA per PC so as most rcd's trip between 18 and 30 mA then you can only plug 2 pc's in ?

 

[shanky887614]

I was involved with one installation in a school, installation and testing only mind you.

We put ( I think) 8 PCs on each ring with the earthing split across each terminal (i.e. not doubled up)

I always understood to allow for up to 10mA earth leakage per PC.

Just my two penneth for what it's (NOT) worth!

what kind of cheap Chinese tat do you work with "voltselectrical" that leaks 10ma to earth?

3.5ma is the max allowed i believe on uk ict equipment in the home (bassically pc's)

considering bronze certifed psu are 80% efficent and platinum 90% i doubt they will leak much to earth

they recommend 6/7 here

https://www.google.com/url?sa=t&sou...BszM8QYDw35DllZlA&sig2=Gv97a5TyT7XqpzHbblfSLw

 

[Darkwood]

what kind of cheap Chinese tat do you work with that leaks 10ma to earth?

3.5mah is the max allowed i believe on uk ict equipment in the home (bassically pc's)

considering bronze certifed psu are 80% efficent and platinum 90% i doubt they will leak much to earth

I was quoting post 40 .... seriously shank you should know im not that out of touch! :dunce2:

The question mark at the end of my post is a clue to my approach on this response.

 

[shanky887614]

I was quoting post 40 .... seriously shank you should know im not that out of touch! :dunce2:

i was being lazy and quoted you instead dw, i know you wouldnt post a comment like that

edited now sorry about that