Is an RCD required in an office?
 

In an office, where there is a small garden, are the sockets that are
supplying the office with a door to the garden *Required* to be RCD
protected?

Ignoring the garden completely, is the any requirement to have RCD
protection in the office at all?
(Office contains the usual officey things, such as PC's lamps, franking
machine, photocopiers, binding machines etc..

The reason I ask, is, the office I am working in at the moment has
approximately 30 PC's
It has three consumer units, all with MCB's and isolator switches.

Another issue is, the radial circuit feeding the server rack will trip when
the UPS is initially turned on, so I feel the wiring may not be up to
standard!

Also, the electricity meter is rated at 40A, when I measured the meter tail,
the office was drawing about 55-65A - the electricity company didn't seem to
worried about it until I told them their main fuse was getting quite warm -
they got this changed to a 100A one, but the meter is still only 40A -
should I be worried?

Sparks...

In article ,
"Sparks" writes:
In an office, where there is a small garden, are the sockets that are
supplying the office with a door to the garden *Required* to be RCD
protected?

No.

Ignoring the garden completely, is the any requirement to have RCD
protection in the office at all?
(Office contains the usual officey things, such as PC's lamps, franking
machine, photocopiers, binding machines etc..

No, actually it's rather unusual to do so IME.

The reason I ask, is, the office I am working in at the moment has
approximately 30 PC's

If there are more than around ~5 or so on one circuit, it should
be wired with high integrity earthing.

It has three consumer units, all with MCB's and isolator switches.

Another issue is, the radial circuit feeding the server rack will trip when
the UPS is initially turned on, so I feel the wiring may not be up to
standard!

Is that an MCB or RCD? UPS's (good ones at least) often draw
almost no current when first switched on. They tend to wait for a
bit to see if the supply is going to stay on before they start
drawing their normal load or switch over their outputs. As such,
they are very nice loads with regards to power up surges.

The office wiring should be getting periodic inspection/test, and
it will typically say when it was last done near the supply head.
The appliances in the office should be getting periodic PAT testing
and have stickers say when they are next due for testing (or serial
numbers which reference a database with that information).

Also, the electricity meter is rated at 40A, when I measured the meter tail,
the office was drawing about 55-65A - the electricity company didn't seem to
worried about it until I told them their main fuse was getting quite warm -
they got this changed to a 100A one, but the meter is still only 40A -
should I be worried?

That seems to be the norm in my experience. I had an office supply
uprated to handle new air conditioning units, and the same was done,
with the meter being potentially over loaded without any apparent
concern (and it didn't get hot AFAICR).

--
Andrew Gabriel

If there are more than around ~5 or so on one circuit, it should
be wired with high integrity earthing.

Can you define this "high integrity earthing" please!
Currently, it is earthed using the supply's armour, with cross-bonding to
the gas and water pipes.

It has three consumer units, all with MCB's and isolator switches.

Another issue is, the radial circuit feeding the server rack will
trip when the UPS is initially turned on, so I feel the wiring may
not be up to standard!

Is that an MCB or RCD?

MCB - there aren't any RCD's, remember :-)
I think it is a 16A MCB, but I will have to have a look when I am next in.

UPS's (good ones at least) often draw
almost no current when first switched on. They tend to wait for a
bit to see if the supply is going to stay on before they start
drawing their normal load or switch over their outputs. As such,
they are very nice loads with regards to power up surges.

It is an APC Smart-UPS 2200 RM if that helps!


The office wiring should be getting periodic inspection/test, and
it will typically say when it was last done near the supply head.

Does should = it must be done at set times? is so, how often?

The appliances in the office should be getting periodic PAT testing
and have stickers say when they are next due for testing (or serial
numbers which reference a database with that information).

They have stickers - however the person who did the testing has not been on
a PAT testing course - is this a requirement?

Also, how often are they required to be tested?


Also, the electricity meter is rated at 40A, when I measured the
meter tail, the office was drawing about 55-65A - the electricity
company didn't seem to worried about it until I told them their main
fuse was getting quite warm - they got this changed to a 100A one,
but the meter is still only 40A - should I be worried?

That seems to be the norm in my experience. I had an office supply
uprated to handle new air conditioning units, and the same was done,
with the meter being potentially over loaded without any apparent
concern (and it didn't get hot AFAICR).

They will also be installing about 10KW of A/C soon - now should I worry!?

Sparks...

Andrew Gabriel wrote:

In article ,
"Sparks" writes:

In an office, where there is a small garden, are the sockets that are
supplying the office with a door to the garden *Required* to be RCD
protected?


No.


Ignoring the garden completely, is the any requirement to have RCD
protection in the office at all?
(Office contains the usual officey things, such as PC's lamps, franking
machine, photocopiers, binding machines etc..


No, actually it's rather unusual to do so IME.


The reason I ask, is, the office I am working in at the moment has
approximately 30 PC's


If there are more than around ~5 or so on one circuit, it should
be wired with high integrity earthing.


It has three consumer units, all with MCB's and isolator switches.

Another issue is, the radial circuit feeding the server rack will trip when
the UPS is initially turned on, so I feel the wiring may not be up to
standard!


Is that an MCB or RCD? UPS's (good ones at least) often draw
almost no current when first switched on. They tend to wait for a
bit to see if the supply is going to stay on before they start
drawing their normal load or switch over their outputs. As such,
they are very nice loads with regards to power up surges.

Almost ALL equuipment that does voltage concversion will either have a
thwacking great iron cored transformer wih may take a HUGE current if
you switch on at the wrong part of tghe cycle, or a thwacking great
capacitor across the mains with just some rectifiers in series to make
it DC.

Both can easily trip an MCB.

In article ,
"Sparks" writes:

If there are more than around ~5 or so on one circuit, it should
be wired with high integrity earthing.

Can you define this "high integrity earthing" please!
Currently, it is earthed using the supply's armour, with cross-bonding to
the gas and water pipes.

It's a feature of the final branch circuit. It depends when it
was wired up how it's done (regs changed). When I installed a
computer room at a previous employer, it was most easily done
by using a ring circuit and ensuring the two ends of the CPC
went into different earth terminals in the distribution panel.
More recent regs require socket outlets with two earth
connections. Radial circuits usually need a second earth
conductor.

It has three consumer units, all with MCB's and isolator switches.

Another issue is, the radial circuit feeding the server rack will
trip when the UPS is initially turned on, so I feel the wiring may
not be up to standard!

Is that an MCB or RCD?

MCB - there aren't any RCD's, remember :-)
I think it is a 16A MCB, but I will have to have a look when I am next in.

UPS's (good ones at least) often draw
almost no current when first switched on. They tend to wait for a
bit to see if the supply is going to stay on before they start
drawing their normal load or switch over their outputs. As such,
they are very nice loads with regards to power up surges.

It is an APC Smart-UPS 2200 RM if that helps!

I tested some ACP Smart-UPS at around 1000VA, and they drew
next to nothing for first ~5 seconds.

The office wiring should be getting periodic inspection/test, and
it will typically say when it was last done near the supply head.

Does should = it must be done at set times? is so, how often?

The employer is responsible for ensuring they provide a safe
workplace for their employees. It would be difficult to claim
you were doing this is you never checked out the premises
wiring. The inspection period depends on its state, how it
is used, and how many problems are typically found during an
inspection. Some employer liability insurance policies insist
on annual inspections (possibly for a discount on premiums).
Otherwise, in the absence of any other information, it should
probably be done every 5 years.

The appliances in the office should be getting periodic PAT testing
and have stickers say when they are next due for testing (or serial
numbers which reference a database with that information).

They have stickers - however the person who did the testing has not been on
a PAT testing course - is this a requirement?

They should be competent to do the testing or they might as well
not be doing it. There's nothing in law which mentions PAT testing,
but it is a way of showing compliance with 4 Acts which apply to
employers. The HSE recognises C&G 2377/02 as an indication the
person is competent to carry out inspection and testing of appliances.
The person who does the testing and the manager responsible for
ensuring it is done should take 2377/02 and 2377/01 respectively.
They are each a 1 day course and exam (and you would normally
do both). They are intended to be doable by non-electricians,
specifically so an office can get one or two employees trained
up to do appliance testing. They will need to know how to wire
a plug, and understand the difference between milliohms and megohms.

Also, how often are they required to be tested?

That's covered in the course. It varies from daily at one extreme
(e.g. for a fairground ride) through to never for some types of
appliance used in some types of situation. With appropriate record
keeping, you can vary the test/inspection periods if you can show
a different period is justified. Something like a desktop computer
which isn't moved around much and isn't used by the public might
be inspected every 2 years and tested every 4 years. You might
decide to write off all your desktops at 4 years old instead of
testing them, as the cost of testing a 4 year old computer probably
exceeds its value.

However, there's not much point testing all your appliances for
correctly connected earths, etc, if you never test your premises
wiring to check the sockets are actually earthed.

Also, the electricity meter is rated at 40A, when I measured the
meter tail, the office was drawing about 55-65A - the electricity
company didn't seem to worried about it until I told them their main
fuse was getting quite warm - they got this changed to a 100A one,
but the meter is still only 40A - should I be worried?

That seems to be the norm in my experience. I had an office supply
uprated to handle new air conditioning units, and the same was done,
with the meter being potentially over loaded without any apparent
concern (and it didn't get hot AFAICR).

They will also be installing about 10KW of A/C soon - now should I worry!?

Whoever is designing the installation should be checking out there's
a suitable electrical supply too. BTW, aircon units are best fed
from dedicated supplies taken from as near the supply source as
you can. Hooking them into a computer room distribution board
which also supplies the computers might lead to sags in the
computer supply voltage on the dist board feeder when compressors
start up.

--
Andrew Gabriel

with the meter being potentially over loaded without any apparent
concern (and it didn't get hot AFAICR).

They will also be installing about 10KW of A/C soon - now should I worry!?



10Kw -- 43A at 230V yes you should worry!!
May I suggest you need a bit of rewire, ask your aircon supplier if they
want single or 3 phase. If you need a 3phase supply you need to ask for a
new electrical supply, and 3 phase is not a first DIY electrical project
particularly in the workplace.
http://www.eece.ksu.edu/~starret/581/3phase.html

Sparks wrote:

Another issue is, the radial circuit feeding the server rack will
trip when
the UPS is initially turned on, so I feel the wiring may not be up to

standard!

illogical. Fwiw a type C breaker might help.


should I be worried?

They will also be installing about 10KW of A/C soon - now should I
worry!?

You like worry dont you. Do you have some reason to believe the ac will
be installed in an unsafe way?


NT

Andrew Gabriel wrote:
The employer is responsible for ensuring they provide a safe
workplace for their employees. ...
They have stickers - however the person who did the testing has not been on
a PAT testing course - is this a requirement?
They should be competent to do the testing or they might as well
not be doing it.

Moreover, as PAT testers use high voltages and the task of testing
necessarily involves working with equipment which is not yet known to be
safe, having someone who has not been trained in how use a tester and
how to inspect equipment before testing is itself an unsafe system of work.

Owain

In article ,
Owain writes:
Andrew Gabriel wrote:
The employer is responsible for ensuring they provide a safe
workplace for their employees. ...
They have stickers - however the person who did the testing has not been on
a PAT testing course - is this a requirement?
They should be competent to do the testing or they might as well
not be doing it.

Moreover, as PAT testers use high voltages and the task of testing
necessarily involves working with equipment which is not yet known to be
safe, having someone who has not been trained in how use a tester and
how to inspect equipment before testing is itself an unsafe system of work.

Indeed. Also, if they're trained, they'll know not to do an insulation
test (the high voltage test) on most IT equipment, where as if they're
not trained, they will likely apply a high voltage test to IT equipment,
resulting in earlier or possibly immediate failure.

--
Andrew Gabriel

Sparks wrote:

They will also be installing about 10KW of A/C soon - now should I worry!?

Yes, make sure that the water that *WILL* inevitably **** out of the air
conditioning units one day has a purely gravity operated method to get
away from your IT kit ;-)