Which is bigger 3A or 13A?

Question

Im going to university in a few weeks and have been told that only appliances with rates under 3 amps should be used but when I look at my hairdryer plug / hair straightners / iron etc they all say 13A and I can't find any with 3A - can I use the 13A appliances? Someone has told me that 3A is bigger than 13A and it would be fine to use them but im not sure to me 13A is bigger than 3A. Can anyone help me with this one? Thanks in advance of you answers

No i havent made a mistake unless the uni has but it says 3amps in the handbook.

Answer 1

13A (A means Amperes - the unit of electrical current) is bigger than 3A. However, just because your hair straighteners have a 13A rating i.e. a 13A fuse in the plaug, doesn't mean that they draw 13A. There may be a current rating on your electrical items or a power rating - kW. You need the kW rating to be less than 0.75kW to be under the 3A.

Answer 2

A plug with a13A fuse will draw more current from the mains before it blows than a 3A. The 3A fuse is more sensitive than the 13A and will blow if the current exceeds 3 amps.

You can work out the amps an appliance will use with this simple formula

amps=Watts/Voltage

In the UK the voltage is rated at 240v. So if you look at the silver plate/label on the appliance and look for the Watts used when on and divide that by 240 you will get a number being the Amps.

If the figure is bigger than 3 then you need a fuse bigger than the 3A. If it is less than 3A you can just swap the fuse over.

However, bear in mind that things with heating elements &/or motors in, hairdryers, kettles etc are all going to draw more current at the time you switch them on (it is called a surge). And this is likely to blow a small 3A fuse.

Answer 3

13Amp is bigger than 3Amp. You may a couple of appliances at home for example. An electric kettle will be fitted with a 13A fuse and an electric clock will be fitted with a 3A fuse. They use the same type of plug, just the fuse is a different rating. Dont take any notice of the Amp rating on the plug its what is on the appliance that counts

Answer 4

BTW the member who said that the the national grid voltage is 310V is slightly off-track - that's the PEAK voltage, as opposed to the root-mean-square or EFFECTIVE voltage of 240V.

And a 13A fuse is still bigger than a 3A! Having said that, though, some appliances, such as hi-fi equipment, have an internal "slow-blow" fuse that handles an initial current surge gracefully, but will still require a 13A fuse in the plug itself.

Answer 5

Thats probably 3 amps per an appliance and 15 amps total for all appliances in use. 13 amps is just being conservative because the typical wall outlet is 15 amps and they most likely only give you one wall outlet to use.

I would recommend you get a portable radio, crank style and battery powered .. for entertainment, towel dry your hair, and have your hair straightened in the beauty shop professionaly.

For light I would get several lamps and connect them to a power strip and use led bulbs in them, led bulbs typically are only 3-5 watts which is way less then the 13 amps total you is limited to.

Remember, volts x amps = wattage, so 120 volts (typical wall outlet voltage) x 13 amps is 1560 watts. 3 -5 watts per a lamp is way under the 13 amps you is limited to, but dont over do it.

Also, get a laptop not a desktop, you can use a laptop off the battery. When the battery is low or dead just charge it up in the class room, library, or when asleep. The Acer TravelMate 4000 series will run for 6 hours unpluged.

Check out www.ccrane.com they have a lot of the products I speak of, except the laptop.

Answer 6

I've never read so much c**p in my life, whats the National Grid got to do with the question?? Anyway its about 400,000 volts. The voltage in the uk is 240 volts single phase in domestic premises. There is no 4000watt domestic hair dryer, it would roast your head. and wouln't work on a 13amp plug. Most hair dryers are 1.5-2 kw or appx. 6.0 - 8.5 amps. A dometic water heater IS normally 3000watts, almost 13 amps.

I suspect that the requirement is to not let the students plug in extra heaters and other heavy current appliances as they probably don't pay extra for electricity.

Three amps will allow about 750watts to be used which will cover almost anything except things that heat up. It may be that the ring/radial circuit in the room is protected by a 3 or 5amp breaker, this would normally be 32 or 20 amps.

Answer 7

It is possible that the rating on the units you are using are 1.3A and not 13A, not even your hot water cylinder is rated at 13A. Most appliances of the sought that you are using and that heat up like a hair dryer are normally rated at 1 to 2 amps.

Answer 8

13 A is bigger than 3A but not many appliances run on less than 3 amps..are you sure thats what it says? maybe a travel hairdrier will run on 3 A
I would be tempted to contact the university and check, even a CD player is 5 to 13 A

Answer 9

I guess you will not be studying physics.
The national grid provides equivalent of 310 Volts.
If your hairdryer is rated at 4000 Watts (or 4kW) (which I severely doubt) then you should be using a 13A fuse
If however, your hairdryer is rated at approx 1000 W or less then a 3A fuse should be OK. Look on the side of each appliance - the power (in Watts) should be shown...

Example
Power = Voltage x Current
If appliance is rated at 4000 W and V = 310
then Current (fuse rating) = 12.9 (13) A

Answer 10

You're friend need to go to college.

13 AMP is more current than 3A. If your limit is 3A then you will not be able to use a hair dryer, kettle or concrete mixer in your room.

If you du, you'll just be £$%$%£$ it up for all your peers as it'll trip the breaker if you all do the same thing.