Room limited to 500 Watts?

[cantab]

A friend of mine is moving into university dorms and has been told the following by the uni:

"Each room is fitted with three 13amp square pin sockets, but it is important to note that the power rating in the study bedroom is rated at a maximum of 500 watts. As a guide, radios, CD players, Hi Fi’s and portable TVs will work. Irons and hair dryers over 500 watts will cause the safety trip to activate affecting the electrical supply to rooms. For safety, the 13 amp plugs used on small appliances in study bedroom should be fitted with 3 amp fuses."

This strikes me as...well, odd. Has anyone here come across such a restriction before and/or can shed light on it?

 

[big-all]

i assume its to stop excessive usage as in no heaters no kettles no cooking no hair tongs

i would assume it would cope with 5 amps this would accommodate a sandwich toasty a microwave and smaller personal care products

 

[bernardgreen]

Not un-common.

Main reason is most often economics. The site will have a maximum economic load setting, if that load is exceeded then the price per kilowatt hour is much higher.

By limiting each student room to a few hundred watts there is less likely hood of the maximum load being exceeded.

It also has the safety aspect that high risk items like fan heaters cannot be used in rooms.

 

[securespark]

Manchester's old YM off Princess Parkway had 1x 3A socket in each of its bedrooms.

 

[JohnW2]

Main reason is most often economics. The site will have a maximum economic load setting, if that load is exceeded then the price per kilowatt hour is much higher.

Given that supplies to individual rooms are generally not metered or charged for, there would be a major economic issue even if what you said were not the case - i.e. 'they' (not the students) would be paying a lot for high electricity usage, even if the price per kWh did not rise at higher loads!

Economics aside, some it probably relates to attempts to avoid 'diversity failure'. When (in the pre-MCB days) I was living in a uni Hall of Residence, goodness knows how many rooms they had wired on each socket circuit. Whilst they got away with this on the basis of 'diversity' for much of the time, it was a very common occurrence for an electrician having to be called out to replace a fuse on Friday and Saturday early evenings, when the female students thwarted diversity, by all plugging in their irons, hair dryers and heated rollers simultaneously!

Kind Regards, John

 

[AdrianUK]

Its always been the same in Halls. In my day (late 80's) we had 2 off 2A round pin sockets in each room & only the MK fused 2A plugs where allowed - and the housekeeper did check!

That didn't stop us making adapter leads from 2A plug to 4 way block so we didnt have to change the plugs on everything! We soon discovered that the 2A sockets where grouped in 6's on 5A MCBs shared between three rooms .... sooo a little maths, a little co-ordination and we where away! We still mamanged to trip the MCB a few times though .... it didnt like powering up two 14" PC monitors at the same time

As others have said, I guess the reason is pure economics ... we had standard 13A sockets in the kitchen that we used for the hairdryer etc & didnt really need any kind of electric heater in the room .... although I did find a 400W oil filled radiator in the junk shop near Uni that came in very handy cold winter of '89!

 

[westie101]

I can't help but think we are well off electrically in the UK! We're used to a minimum of a 60A supply, (though with fuses & fusing factors it is rather higher)

We've started caravanning so are getting used to a 16A hook up (though there are sites only supplying 10A in the UK and as low as 6A in Europe).
A friend was recently telling me that they are limited to 40A max at her house in a city in Northern Italy, this is a common capacity there and will automatically trip if above that figure.
She was quite surprised when I told her that 100A was common in the UK

 

[JohnW2]

Its always been the same in Halls. In my day (late 80's) we had 2 off 2A round pin sockets in each room & only the MK fused 2A plugs where allowed - and the housekeeper did check

Indeed. My experiences are mainly from the late 60s, and I honestly can't recall what sort of sockets we had. However, as I described, many people clearly found ways to connect relatively high-powered appliances to them (even if they wew 2A, 3A or 5A sockets!). Mind you, I seem to recall that, rather like hospitals and many hotel bedrooms these days, they erred on the side of being over-generous with the central heating, so we rarely, if ever, had to supplement it with heaters of our own.

Kind Regards, John

 

[JohnW2]

A friend was recently telling me that they are limited to 40A max at her house in a city in Northern Italy, this is a common capacity there and will automatically trip if above that figure.

Do I take it that they don't have electric showers or cookers?

Kind Regards, John

 

[westie101]

I didn't get a list of equipment or cooking type, but was told that if she has the dishwasher, the washing machine & the water heater on - hoovering the floor is impossible.

I suggested time-switches for the first two appliances to operate them at night

(the conversation took place at a party at about 2am as she & her husband were cooking us all some pasta as a snack)

 

[AdrianUK]

Do I take it that they don't have electric showers or cookers?

They might, I rented a serviced apartment in Kuala Lumpur last year (I was in the City for 4 weeks with work) and it had an electric shower... howver, it was only a 4kW heater but this was more than capable of raising the temprature of the incoming "cold" water upto a decent shower temperature.

Incidentially I found it very strange that all the sinks/washbasins etc that I came across nly had the one tap ... cold, or rather tepid, there was no hot water!

 

[OwainDIYer]

A friend was recently telling me that they are limited to 40A max at her house in a city in Northern Italy, this is a common capacity there and will automatically trip if above that figure.

A lot of Italian houses are limited to 3kW (13A), 40A would be a luxury (and much more expensive)

 

[westie101]

40A would be a luxury (and much more expensive)

That fits as it's quite a large detached house (and he's a senior pilot)

 

[ban-all-sheds]

Tariffs based on maximum demand are the norm in France - a 60/80/100A supply would be ruinously expensive.

Load shedding relays within domestic properties are used to prioritise appliance usage.

 

[crystal ball]

When I was working in Zimbabwe it was common to find a 7amp mcb on the unmetered incomer to staff housing in schools etc. All were charged at flat rate included in rent