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How do electrical circuits work?
Comments
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No it isn't ! a short to earth will have blown the fuse or MCB
As stated it will have been an earth fault ..... thank you
For techy reasons I won't bore you with, under an earth fault in this situation I would expect the RCD (if fitted) to respond significantly faster than an MCB or fuse, so if there is an RCD fitted in the circuit then I wouldn't expect to find a blown fuse or MCB.
But, either way, by the sounds of it the toaster is toast, which is by far the most cost effective option for the OP. AND...they know that at least their electrical installation is protecting them and doing its job.0 -
.........For starters, a fuse will not 'take tens of amps for ages', neither will an MCB respond faster. A BS1361 fuse will take roughly 3 x In (rated amps) for 5 secs whereas as a BS-EN 60898 B (commonly found domestic MCB) will take roughly 5 x In /5s....therefore meaning that a fuse is actually 60% faster amp for amp than an MCB......
But doesn't a 60898 B type at 5In have to come out in 400mS or less to comply with BS7671?
Also I think to meet the 60898 standard it needs to open in 100mS or less.0 -
But doesn't a 60898 B type at 5In have to come out in 400mS or less to comply with BS7671?
Also I think to meet the 60898 standard it needs to open in 100mS or less.
Yes to the first - disconnection time for the final CIRCUIT is under 400mS (or 5s for a supply circuit), as to what the exact 60898 standard is, in fairness can't tell you as I can't think I've ever had reason to read it!!
But now....I'm going to, as every day is a school day!!
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But doesn't a 60898 B type at 5In have to come out in 400mS or less to comply with BS7671?
Also I think to meet the 60898 standard it needs to open in 100mS or less.
Have you been looking at the time curve graphs (from 0.1 to 5 sec )or are you getting confused with a 100 milliamp rcd or rcd trip times? I'm not sure where your 100mS has come from0 -
I think the time curves deals with all possibilities, the 60898 standard requires standardised tests from cold and requires trip in 100mS at 5In for B type mcbs.
Along the same lines the currents from the 7671 earth loops for 400mS disconnection times also come out at 5In for B types0
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