Global Scale Modeller

Hi folks
just had a problem with my spray booth and ended up checking the fuse
to my horror I found both my booth and compressor had 13amp fuses in

both items are from the cheaper end of the market but a fault could have resulted in overheating or worse

so have a quick check of your fuses - make sure they have 3 amp fuses fitted
(red fuse not brown)

just for piece of mind

I don't have a spray commercial spray booth Graham, but what type of compressor do you have?
I'm just wondering if the problem is specific to a particular brand, make, and model.

Will have to check mine when I get home.

Cheers for the heads up though.

Very good point Graham

This might be a stupid question but why does it need to be a 3amp instead of a 13amp I just checked my compressor and it has a 13amp fuse in the plug

Mine doesn't even have a fuse.

BrummieModeller wrote:This might be a stupid question but why does it need to be a 3amp instead of a 13amp I just checked my compressor and it has a 13amp fuse in the plug

Hi - no a very good question

this is a UK electrically connected main plug.

My compressor is an AS18-2
at 220V a 3 amp fuse will blow if there is a continuous current flow of <3 amps for a period of time (ie it gets hot and snaps)
or when there is a surge of current demanded by the compressor (e.g. if there is short circuit to earth or if the motor jams)
this is a safety device to prevent damage to your equipment and wiring which would over heat and possible catch fire
so by fitting the lowest rating fuse you protect your equipment and enviroment (stops it catching fire)

a 3 Kilowatt rated Kettle will draw 13A from a 220V supply - hence the need for a 13 amp fuse
but a TV for example is rated at about 500 watts - this will draw approx 2.3 Amps - hence a 3 amp fuse
A Desktop PC has a 300Watt power supply in most cases - again just needs 3 Amp Fuse

i would say a compressor is around 500W so 3 amps is quite big enough (but if the wattage is marked then check by all means)

my spray booth is just a small fan in a box - i doubt it would be more than 300W (1.4A)

a 13 Amp fuse would be used in a Arc Welder, Kettle, Electric Fire, Electric Oven - really anything that gets hot

now the maths

Voltage (V) X Amps (I) = Watts (W)

or Amps (I) = Watts (W) divided by Voltage (V)

in general terms
3Amp fuse use up to 600 Watts
5Amp Fuse use up to 1100 Watts
13Amp Fuse anything above this up to 3000 Watts (3 Kilowatts)

generally in the UK a domestic mains supply is rated at 100A, the ring main (sometimes 2) has a 30A rated fuse in the mains fuse box. this rating is to protect the wiring not the applance.
UK wiring provides a fuse in the main plug for appliance protection,
many appliances also have a fuse inside (this often fails as the result of a fault developing - often this fuse is rated in milli amps)

the wattage of an item is it's measured at a maximum comtinuous load - at most times it will draw a lot less that the rated wattage

hope this helps

I have one of the cheaper compressors as well, so will be sure to check mine. Chances are its got a 13 Amp fuse in it, which means I should stick a 3Amp one in there instead.

Oh, and nice to see someone from Tamworth, my gf is from just outside Kingsbury lol. I made her move up to Scotland though, much nicer :-P

graham22 wrote:

BrummieModeller wrote:This might be a stupid question but why does it need to be a 3amp instead of a 13amp I just checked my compressor and it has a 13amp fuse in the plug

Hi - no a very good question

this is a UK electrically connected main plug.

My compressor is an AS18-2
at 220V a 3 amp fuse will blow if there is a continuous current flow of <3 amps for a period of time (ie it gets hot and snaps)
or when there is a surge of current demanded by the compressor (e.g. if there is short circuit to earth or if the motor jams)
this is a safety device to prevent damage to your equipment and wiring which would over heat and possible catch fire
so by fitting the lowest rating fuse you protect your equipment and enviroment (stops it catching fire)

a 3 Kilowatt rated Kettle will draw 13A from a 220V supply - hence the need for a 13 amp fuse
but a TV for example is rated at about 500 watts - this will draw approx 2.3 Amps - hence a 3 amp fuse
A Desktop PC has a 300Watt power supply in most cases - again just needs 3 Amp Fuse

i would say a compressor is around 500W so 3 amps is quite big enough (but if the wattage is marked then check by all means)

my spray booth is just a small fan in a box - i doubt it would be more than 300W (1.4A)

a 13 Amp fuse would be used in a Arc Welder, Kettle, Electric Fire, Electric Oven - really anything that gets hot

now the maths

Voltage (V) X Amps (I) = Watts (W)

or Amps (I) = Watts (W) divided by Voltage (V)

in general terms
3Amp fuse use up to 600 Watts
5Amp Fuse use up to 1100 Watts
13Amp Fuse anything above this up to 3000 Watts (3 Kilowatts)

generally in the UK a domestic mains supply is rated at 100A, the ring main (sometimes 2) has a 30A rated fuse in the mains fuse box. this rating is to protect the wiring not the applance.
UK wiring provides a fuse in the main plug for appliance protection,
many appliances also have a fuse inside (this often fails as the result of a fault developing - often this fuse is rated in milli amps)

the wattage of an item is it's measured at a maximum comtinuous load - at most times it will draw a lot less that the rated wattage

hope this helps

Thank you for trying to explain but just confused me haha but yeah like gav said I have same as his so il have to change it

Basically here is my compressor looks different to others peoples I seen they have a red and black knob for the pressure I don't duno why either but anyways if anyone can work out weather I do need to change the fuse then let me know and It will be gratefully appreciated

1/6 HP motor is about 150watts
so 3 amp is plenty

graham22 wrote:1/6 HP motor is about 150watts
so 3 amp is plenty

Ok thanks mate I will change it then at least it will be safer

Are you a sparky by any chance lol ????

BrummieModeller wrote:

graham22 wrote:1/6 HP motor is about 150watts
so 3 amp is plenty

Ok thanks mate I will change it then at least it will be safer

Are you a sparky by any chance lol ????

nope not a sparks, telecom engineer,

so needed to know correct fuses for equipment at customers premises.

Yup, just checked mine, horrorfied to find a 13!

Mine is one of the cheap AS ones.

I've changed mine now thanks to the brainbox that is graham22

Just checked mine, AS186 - it too had 13 amp in it. Changed now - cheers Graham

Thanks for the heads-up Graham, defo going to check mine.

Just a thought, a lot of the cheaper compressors were originally intended for non-UK markets where the power supply is via 2-prong sockets and probably why they chuck 13-amp plugs on the end. In these cases the appliance itself is fused, but not always as in some countries they insert the fuse into the socket - yikes!! I would definitley apply caution and if in any doubt stick a 3-amp in the plug just as Graham advised.

Not like the good old days when you had to put your own plugs on everything - oh, and there were way more house fires!!

very true - the chances are the manufacturer bought 13A power leads and just installed them for the UK market, whilst the power lead may well be 13A rated - the chances are the internal wiring would be appropriate to the requirements of the compressor - there is prob some sort of Transformer and/or Bridge rectifier to reduce to DC/lower voltage but as it the motor is only about 150 Watts 3 A is more than enough - this also will give better protection if there is a fault and will keep any heat from building up