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So I have had an enquiry about a large open plan call center with around 150 desks.
Rented office space, each desk has at least 1 pc with 2 monitors.
There is also all the other IT equipment you would expect in a big office.
The office sockets are fed from 2 x bus bar trunking runs under the floor.
Each of these is fed from a 40A RCBO via swa cable.
There are many floor mounted boxes each with 2 x twin sockets that are plugged in to the trunking system that then run the office equipment at the desks. Singles in flexible conduit, steel spiral type.
Problem is the RCBO’s are tripping at random intervals, sometimes in the day and sometimes overnight.
I have logged the current on each circuit for 5 days and found max load in the region of 30A on both circuits with no peak before current drops to 0 (breaker tripped)
All equipment has been recently pat tested and has a clean bill of health.
The obvious diagnosis is that a cumulative leakage from all the IT equipment is tripping the RCBO.
There are 2 ways I am considering dealing with this,
OPTION 1
Split the trunking into 4 runs instead of 2 fed from 4 x 40A RCBO’s
This will probably fix the issue and is the cheaper and quicker option.
OPTION 2
Change the RCBO’s to Standard breakers.
Mark the trunking runs along there length with warning about lack of rcd protection.
Change all the socket outlets to rcd sockets.
This is my preferred option, it would still provide protection to all outlets.
A fault on one socket won’t black out half the office but be confined to that socket only.
What are people’s thoughts?
In my mind, both options comply with regs.
The trunking is not accessible without lifting the floor.
Rented office space, each desk has at least 1 pc with 2 monitors.
There is also all the other IT equipment you would expect in a big office.
The office sockets are fed from 2 x bus bar trunking runs under the floor.
Each of these is fed from a 40A RCBO via swa cable.
There are many floor mounted boxes each with 2 x twin sockets that are plugged in to the trunking system that then run the office equipment at the desks. Singles in flexible conduit, steel spiral type.
Problem is the RCBO’s are tripping at random intervals, sometimes in the day and sometimes overnight.
I have logged the current on each circuit for 5 days and found max load in the region of 30A on both circuits with no peak before current drops to 0 (breaker tripped)
All equipment has been recently pat tested and has a clean bill of health.
The obvious diagnosis is that a cumulative leakage from all the IT equipment is tripping the RCBO.
There are 2 ways I am considering dealing with this,
OPTION 1
Split the trunking into 4 runs instead of 2 fed from 4 x 40A RCBO’s
This will probably fix the issue and is the cheaper and quicker option.
OPTION 2
Change the RCBO’s to Standard breakers.
Mark the trunking runs along there length with warning about lack of rcd protection.
Change all the socket outlets to rcd sockets.
This is my preferred option, it would still provide protection to all outlets.
A fault on one socket won’t black out half the office but be confined to that socket only.
What are people’s thoughts?
In my mind, both options comply with regs.
The trunking is not accessible without lifting the floor.