13 amp plug fuses

[brightspark]

they will take a fair bit of punishment before they will blow. plugged a faulty 12 volt transformer in today in garage nothing else running. a nice big bang occurred checked the fuse in the tester connector that was ok checked 13 amp fuse in the 13amp plug its ok and it had taken the 32 amp b type mcb out . reset it and still nowt no power to garage it took the 40 amp mcb out as well

 

[mtt.tr]

Mcbs are really rather impressive.

 

[Bladevane]

Is that because MCBs operate on 32mA or 100mA mismatch between line and neutral? I have always believed a fuse is there to protect the wiring, not the equipment.

 

[brightspark]

Mcbs are really rather impressive.

and a pain I the butt sometimes

 

[AndersK]

Try starting up a 135 kW motor with an Y- D starter where the electrician has connected delta as reverse rotation
Whole building was shaking while a lot of very large fuses blew

 

[brightspark]

Is that because MCBs operate on 32mA or 100mA mismatch between line and neutral? I have always believed a fuse is there to protect the wiring, not the equipment.

rcd is for earth leakage protection 30ma and 100ma an mcb is for overload protection overload

 

[brightspark]

couldn't get a 40 amp c type breaker so put a b type in temp will have to change it to a c type now the wholesalers are open

 

[mtt.tr]

and a pain I the butt sometimes

Yep 110v box.

 

[mtt.tr]

Is that because MCBs operate on 32mA or 100mA mismatch between line and neutral? I have always believed a fuse is there to protect the wiring, not the equipment.

No that's rcds.


Wire fuses rely on the wire over heating and breaking
Mcb do the same job but electromechanically.

 

[tlovatt]

For a 13A BS1362 fuse to burn out in about 1 second typically takes about a minimum of 32A current but could be as high as 80A and still be in specification, a 13A fuse should allow a 20A current to flow indefinitely (save for effects such as repeated thermal stressing)

To blow in 1/10 of a second (which is still relatively slow) can take between 50A and 120A and still be in spec.
To blow in 1/100 of a second can take between 100A and 300A and be in spec

With MCBs fitted there is a limited amount of use in fuses, the reason is the need to limit the heat generated by the fuse in normal operation so the plug does not overheat.

 

[Screwdriver]

Try starting up a 135 kW motor with an Y- D starter where the electrician has connected delta as reverse rotation
Whole building was shaking while a lot of very large fuses blew

What speed does it get up to before it switches? That's a lot of kW!

 

[Woody.v8]

What speed does it get up to before it switches? That's a lot of kW!

PPFFT, We had some 5000kw motors that if you started them you had to contact the national grid! Although proper sparks had connected them so even the basic wiring was done correctly.

 

[Screwdriver]

PPFFT, We had some 5000kw motors that if you started them you had to contact the national grid! Although proper sparks had connected them so even the basic wiring was done correctly.

You mean proper sparks with, wot, qualifications and everything?

 

[Woody.v8]

You mean proper sparks with, wot, qualifications and everything?

No people who know what they are doing, get the box of chips off your shoulder, I wasn't even getting at you , I was referencing the post you quoted.

 

[tlovatt]

PPFFT, We had some 5000kw motors that if you started them you had to contact the national grid! Although proper sparks had connected them so even the basic wiring was done correctly.

It is unusual to contact the grid for a little motor like that, we work on motors and generators up to 600,000kw out on sites and will bring ~100,000kw turbo generators into the workshop on occasions.

 

[mtt.tr]

Do did you lot decide who has the biggest penis?

 

[Woody.v8]

Do did you lot decide who has the biggest penis?

I can't even play the piano

 

[DAPPH]

No people who know what they are doing, get the box of chips off your shoulder, I wasn't even getting at you , I was referencing the post you quoted.

As my instructor John White often quoted to us, " Proper electricians , not plumbing electricians or chancers " . ( John was the hands on chief electrical officer in the first dreadnought atomic sub )

 

[mtt.tr]

As my instructor John White often quoted to us, " Proper electricians , not plumbing electricians or chancers " . ( John was the hands on chief electrical officer in the first dreadnought atomic sub )

When my dad was with the gpo he said the failed electricians were sent to the gas board.

 

[AndersK]

What speed does it get up to before it switches? That's a lot of kW!

It runs for a good 4-5 sec before switching so it should be full speed.