What is "unwanted tripping"?

[pc1966]

So why wouldn't a 13amp fuse blow before a 32amp circuit breaker?

Just look at the current/time plots for them.

Typically with a fuse and larger MCB you will find generally:

1. The fuse blows first (up for PFC up to the MCB magnetic trip point)
2. Then you find the MCB trips first, and the fuse survives (if MCB I2t let-through is below the per-arcing I2t of the fuse)
3. At very high PFC you find the MCB trips but the fuse has also blown (as the blows in under the time for the MCB to operate, typically 5-10ms).

 

[Coby01]

Rational Argument:
Domestic general purpose socket outlet circuits;
2.5mm ring final circuit, protected by 25amp BS EN 60898 mcb, supplying BS 1363 plastic socket outlets.
Light industrial general purpose socket outlet circuit;
4.0mm ring final circuit, protected by 32amp BS EN 60898 mcb, supplying BS 1363 'metalclad' socket outlets.

History:
Domestic general purpose socket outlet circuits;
2.5mm ring main, protected by 30amp fuse carrier with 20amp fuse wire/cartridge, plastic socket outlets.
Light industrial general purpose socket outlet circuits;
4.0mm ring main, protected by 30amp fuse carrier with 30amp fuse wire/cartridge, 'metalclad' socket outlets.

 

[westward10]

Rational Argument:
Domestic general purpose socket outlet circuits;
2.5mm ring final circuit, protected by 25amp BS EN 60898 mcb, supplying BS 1363 plastic socket outlets.
Light industrial general purpose socket outlet circuit;
4.0mm ring final circuit, protected by 32amp BS EN 60898 mcb, supplying BS 1363 'metalclad' socket outlets.

The argument being?

 

[Coby01]

The argument being?

The plastic socket outlet couldn't cope with the temperature at Grenfell.

 

[Coby01]

The plastic socket outlet couldn't cope with the temperature at Grenfell.

Question of 'moderator' credibility?

 

[westward10]

Question of 'moderator' credibility?

What exactly are you getting at.

 

[DPG]

Question of 'moderator' credibility?

I think you need to state your point(s?) more clearly. I don't have a clue what you are on about.

 

[Lucien Nunes]

The important working parts of a metalclad socket-outlet (near the points at which heat is generated) are usually made of the same plastics as an all-plastic one, although an enclosure with more of its surface made of metal might provide better containment of burning material from within. Within a BS1363 plug and socket-outlet pair, heat is generated mainly at points of high current density, such as (in approximately decreasing order of significance)

• Fuse element
• Fuse clips
• Socket contacts
• Switch
• Plug terminals
• Socket terminals

Thus two of the principal sources of resistive heating are outside the containment offered by a metal socket faceplate anyway. The quality of manufacture, installation and any deterioration of the contact surfaces are key factors in the resistance at various points and the heat generated. So too is the effect of heat on the long-term stability of resistance, which is markedly poor in low-quality accessories.

Or have I missed the point? This whole thread seems to be an exercise in trolling by someone with knowledge of electrical principles, or an attempt to cheese everyone off by someone without, by repeatedly making false statements. I can't tell.

 

[Coby01]

Question of moderator credibility again?

Editing out the truth!

 

[DPG]

Question of moderator credibility again?

Can you clarify what you are getting at?

 

[westward10]

@Coby01 I have just PM'd you.

 

[Coby01]

Not everything that I write is getting past the moderator.

 

[westward10]

Not everything that I write is getting past the moderator.

See #51

 

[westward10]

If you look on the home page the envelope in the top right corner should indicate a message. Reply to this message.

 

[SparkyChick]

Don't think the OP will be back if you catch my drift

Thanks everyone for resisting the urge to say what you really felt.

 

[DPG]

Don't think the OP will be back if you catch my drift

Thanks everyone for resisting the urge to say what you really felt.

It's a strange carry on. I dare say he'll be back with some more bizarre postings in a few months.

 

[westward10]

It's a strange carry on. I dare say he'll be back with some more bizarre postings in a few months.

That is unlikely.