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MCB/RCD on consumer unit tripping

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Geoff1946
48 minutes ago, binky said:

6A max I presume? 

Yes if the circuit is loaded to maximum but that will be rare on modern (led) lighting. If I put on every light in my house, simultaneously, I don't think I would reach 500 watts, so < 3amp..

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Sidewinder
16 hours ago, Murdoch said:


The next one is 83 but I haven’t listened to them all

 

anything over 45 minutes is past my tolerance and some aren’t relevant so I will stop listening and delete it 

 

I found the series on SPD particularly tedious .... 

 

people blowing their own trumpets need editing out

You probably ignored and deleted my first one then.

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Sidewinder
14 hours ago, Andy™ said:

 

sp in a house with all LED lighting (and even non LED lighting), the max current for the entire circuit with everything on at the same time is far less than 2.5a, then having an AFDD would be of no use


The argument there is that an arc at 230V & 2.5A does not have enough energy for ignition of the insulation, hence no requirement for detection.

The only place that falls down is a parallel arc at the start of a short circuit in the wiring, but, the argument there is that it will quickly cascade into a short circuit and the MCB will then trip.

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Sidewinder
1 hour ago, binky said:

6A max I presume? 

No the current will be the actual real time loading on the circuit, so if it's just a few LED's with only one on, it will be just the load of say the one 5W LED.

So perhaps in the mA range.


Also see my other post for the theory behind this.

I have a good idea how they function etc. because I was invited to Eaton in Vienna to look at their ideas behind the development.

39 minutes ago, Geoff1946 said:

Yes if the circuit is loaded to maximum but that will be rare on modern (led) lighting. If I put on every light in my house, simultaneously, I don't think I would reach 500 watts, so < 3amp..

Exactly.

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binky
40 minutes ago, Sidewinder said:

No the current will be the actual real time loading on the circuit, so if it's just a few LED's with only one on, it will be just the load of say the one 5W LED.

So perhaps in the mA range.


Also see my other post for the theory behind this.

I have a good idea how they function etc. because I was invited to Eaton in Vienna to look at their ideas behind the development.

Exactly.

so not likely to be any use on lighting circuits then? 

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UNG

I am getting a bit cautious of new regs where Grenfell is used as a reason for there introduction, there are so many theories as to what happened at Grenfell and I have heard so many different stories of what supposedly was the cause of the fire I'm now beginning to wonder if the true cause will ever be resolved and positively identified . If the fire was caused by a fridge / freezer why has there been no recall or checks instigated on the model of fridge / freezer involved over 3 years on, surely if the seat of the fire is an appliance then this potentially presents a bigger risk to more lives and households than how the cladding on a building allowed the fire to spread. Maybe we need an inquiry into why these inquiries take so long and cost so much to produce any meaningful results

 

When you look at the information available there are too many if's with AFDD's with regard to what they can detect and when they will operate, currently we can check an RCD / RCBO is operating correctly and within tolerance with the appropriate test equipment, other than pressing a button on the front of an AFDD we have no other means of verifying it's correct operation and that it is still within tolerance. Then there is the question how do you identify a faulty AFDD or a fault on the circuit, I don't know if AFDD's susceptible to mains borne noise or harmonics which would then cause nuisance trips

 

Mandating the use of AFDD's will no doubt in the short term have an effect on the general safety of older installations as the cost to update an old CU will become considerably more expensive and beyond some householders budgets, it remains to be seen if AFDD's will become a lot cheaper as more are used and production is ramped up to meet the increased demand and the cost of CU's become more affordable again

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Andy™
6 hours ago, binky said:

when a broken conductor or loose connection is arcing it probably draws more than 2.5A 

cant really pull any more than that load connected to it. if it did somehow pull a lot of current then the MCB would detect it

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Sidewinder
1 hour ago, binky said:

so not likely to be any use on lighting circuits then? 

Correct

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Sidewinder
7 minutes ago, UNG said:

I am getting a bit cautious of new regs where Grenfell is used as a reason for there introduction, there are so many theories as to what happened at Grenfell and I have heard so many different stories of what supposedly was the cause of the fire I'm now beginning to wonder if the true cause will ever be resolved and positively identified . If the fire was caused by a fridge / freezer why has there been no recall or checks instigated on the model of fridge / freezer involved over 3 years on, surely if the seat of the fire is an appliance then this potentially presents a bigger risk to more lives and households than how the cladding on a building allowed the fire to spread. Maybe we need an inquiry into why these inquiries take so long and cost so much to produce any meaningful results

 

When you look at the information available there are too many if's with AFDD's with regard to what they can detect and when they will operate, currently we can check an RCD / RCBO is operating correctly and within tolerance with the appropriate test equipment, other than pressing a button on the front of an AFDD we have no other means of verifying it's correct operation and that it is still within tolerance. Then there is the question how do you identify a faulty AFDD or a fault on the circuit, I don't know if AFDD's susceptible to mains borne noise or harmonics which would then cause nuisance trips

 

Mandating the use of AFDD's will no doubt in the short term have an effect on the general safety of older installations as the cost to update an old CU will become considerably more expensive and beyond some householders budgets, it remains to be seen if AFDD's will become a lot cheaper as more are used and production is ramped up to meet the increased demand and the cost of CU's become more affordable again

It is generally accepted that the fire started in an appliance, the condition of which was unknown, it is felt that it had a plastic back, there has been some discussion about this being deemed unacceptable.

 

A lot of appliances are unsafe, a lot of goods purchased via online marketplaces are unsafe and not legal for use in the UK.

What people do not realise is if they procure an item personally from outside the UK (was EU), then they become the legal importer and are responsible for the safety of the product.

In the scenario where say a hair straightener is purchased via an online marketplace and the seller is outside the UK, and say the unit catches fire and burns their house down, their house insurer could sue them personally for the losses as the legal importer, and it would be down to the individual to sue the manufacturer abroad, possibly China for their losses.

 

There are, some, if's and yes there is the prospect of nuisance tripping, however, most on the UK market will indicate are of the combined type and will indicate if the fault detected is, arc, overcurrent or leakage.

i.e. AFDD/MCB or RCD which has caused the trip.

Thus from that one can quickly identify whether it is an arc or not.

They all have inbuilt diagnostics which will quickly become a nuisance if the device goes faulty.

 

The short term effect will be that installations will not be upgraded, however, it will be the poorer that are most at risk from this, and this is fine for the ruling class as they want to rid themselves of the less well off.

Therefore they are not concerned.

Those who can afford to have the upgrades will be safe and thus will have reasonable funds.

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Murdoch
5 hours ago, Sidewinder said:

You probably ignored and deleted my first one then.


what number was it. I do remember one with a lot of chat about travelling abroad ...

 

actually I’m up to 67 now and both 66 and 67 had the time about spot on 

 

 

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Sidewinder
35 minutes ago, Murdoch said:


what number was it. I do remember one with a lot of chat about travelling abroad ...

 

actually I’m up to 67 now and both 66 and 67 had the time about spot on 

 

 

Not a clue what number it was!

I've not had the chance to listen to them all myself.

 

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binky
23 hours ago, Sidewinder said:

 

The short term effect will be that installations will not be upgraded, however, it will be the poorer that are most at risk from this, and this is fine for the ruling class as they want to rid themselves of the less well off.

Therefore they are not concerned.

Those who can afford to have the upgrades will be safe and thus will have reasonable funds.

 

Everything in this country seems to be increasingly at the expense of the poor /less well off.  :(

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