Dodgy Electrics

[Leo1983]

OK, checked the fuse box and sockets are all on one ring main so using different rooms will make no difference.

I am going to invest in the 2 most heavy duty extension leads I can find (including RCD) and plug them into seperate sockets to distribute the load, and i'll buy 2 new kettle leads from brewbuilder so start from a clean slate and monitor closely.

I do think the extension leads have been the cause of these issues so hopefully this will fix things.

Extension Leads - (Extreme 2.5mm wire versions at £25 a go!)
https://www.industrialextensionlead...t-13amp-heavy-duty-extension-lead-10285-p.asp

New cables (same ones from brewbuilder)
https://www.brewbuilder.co.uk/lead-2-4kw-element.html

Any better/cheaper options for those out there?

 

[britton]

Make sure you fully unwind the extension leads, leaving then cooled up reduces their rating .

 

[connor7932]

although you have a ring main,what you are plugging into may be a 2.5m spur.check it!.

 

[Leo1983]

Right, sounds like the extension leads I was using will likely be the cause of this.

I'm going to get 2 new extension leads and 2 new kettle leads to start on a fresh setup and monitor it closely.

Checked the fuse box and all sockets (except the cooker) are on the same ring main so I will continue plugging each extension lead into its own wall socket, but different rooms wont make any difference.

These are the best I can find online (£25 a go too), the 2.5mm cable versions rated at 24 amp and with RCD:
https://www.industrialextensionlead...t-13amp-heavy-duty-extension-lead-10285-p.asp

And 2 new ones of these from Brewbuilder
https://www.brewbuilder.co.uk/lead-2-4kw-element.html

Any better options based on cost or quality i'm all ears. Otherwwise I will get those and keep close watch next brew day.

 

[Leo1983]

LOL wow... I thought my first post didnt work so re-wrote and posted again... I even looked but didn't see the link to page two where my post was... and I work in IT... and i'm playing with water and electricity... maybe I should find another hobby!

 

[BREWERS DROOP]

Get an electrician in,or you may not be here next time round,

 

[Hoddy]

Right, sounds like the extension leads I was using will likely be the cause of this.

I'm going to get 2 new extension leads and 2 new kettle leads to start on a fresh setup and monitor it closely.

Checked the fuse box and all sockets (except the cooker) are on the same ring main so I will continue plugging each extension lead into its own wall socket, but different rooms wont make any difference.

These are the best I can find online (£25 a go too), the 2.5mm cable versions rated at 24 amp and with RCD:
https://www.industrialextensionlead...t-13amp-heavy-duty-extension-lead-10285-p.asp

And 2 new ones of these from Brewbuilder
https://www.brewbuilder.co.uk/lead-2-4kw-element.html

Any better options based on cost or quality i'm all ears. Otherwwise I will get those and keep close watch next brew day.

Ok look, I’m just going to chip in here. But you have been urged to obtain so advice from a qualified electrician that can actually see what it is your doing first hand.

But here are a few pointers -

Using an extension lead (particularly heavy duty ones) will just make the current draw (load) bigger, and could cause you more problems. You’ll get a bigger volt drop which only increases the load and hence more overheating issues.

I’m not happy about the fact your live switching two heating elements that have no thermal regulation (basically they are going full chat all the time) and hence you pulling maximum power and things are melting. And you only way of switching this is via a socket switch.

This sounds like you need someone to properly assess what you need and most likely a separate supply MCB put into your distribution board to run such a decent load. Until then I recommend if you can’t wait to a) get an industrial extension lead and replacement for an element b) just run ONE heater when doing a boil. It may take longer but I think until a spark has been in. It’s the far safer option next to doing nothing. c) get a propane burner and don’t risk setting fire to your house.

(I’m a qualified 21 year time served industrial electrical engineer)




Sent from my iPad using Tapatalk

 

[Leo1983]

OK looks like a resounding 'get someone who knows what they are bloody doing before you kill yourself' response.... so i will take that advice.

My mate is a spark so i will get him to take a look once he's finished moving house. I have bought the pricey extension leads above already, so hopefully they wont be a waste of cash. Must be an improvement over the others i have which cost a few quid from tesco or the like (hopefully).

I read posts on forums a lot. Especially before I buy something to do with a hobby, and I remember reading lots about all grain brewing threads before I did my first brew using a one element plastic bucket boiler (which also had a hot plug problem), but nowhere made much mention of the potential dangers of elecric brewing.

If this is as dangerous as stated, and from reading the posts (especially that from Hoddy above) I don't doubt it, maybe this should be made much clearer to new and less new brewers of what checks need to be made before accidents happen.

 

[Dutto]

Being clumsy (and having the scars to prove it) I put one of these in the socket before I do anything with electrical equipment outside ...

https://www.amazon.co.uk/dp/B01NCSVJTY/?tag=skimlinks_replacement-20

I bought an extendable electric Hedge Trimmer from Lidl last week and fitted the RCD "just in case".

So far I haven't managed to cut the cord and trigger the RCD ...

... but according Murphy's First Law it's only a matter of time before I do!

 

[Clint]

Christ Dutto...get a man in!

 

[Dutto]

Christ Dutto...get a man in!

I'm not impervious to pain but I loathe spending money! Have you seen the cost of "Bob-a-Job" week nowadays? Thieving little gits!

My Mum used to tell me "Go and see Mrs. Brown and ask her if she needs anything."

Mrs. Brown, a neighbour three doors down the terrace, always without fail needed something from the shop half a mile away and always without fail asked me the same question when I got back with the goods.

"Now what would you like for running that errand?" she used to ask, "A thrupenny bit or a slice of bread and dripping?" ...

... and before I could answer would carry on with "A slice of bread and dripping will do you more good." and go away to make it!

I ran errands for that old bugger for nearly eight years and I never got so much as a penny for my troubles!

Get a man in! Yeah, right!

SWMBO might need to get someone in to carry my coffin but even then I hope she pays him in booze!

 

[Clint]

I got a Mrs Brown three doors down!

 

[AdeDunn]

I don't know where you did your reading friend, but when I was researching my boiler build I came across tons of posts explaining about the need to spread the load when using multiple elements. That's the reason I only used a single 10 amp, 2.4kw element, which just about gives me a nice rolling boil in my 33 litre boiler build.

Is your boiler really so big that you need both elements on at once?

Re-read your first post. 50 litre boiler, surely you can run that with a single 3kw element? Rig it to a controller box with a voltage controller too so you can control the boil better, rather than run full whack constantly, insulating the outside of the boiler will help too by keeping the heat in.

 

[alarmsparks]

I have read the reply with interest. I am a qualified electrician.

Golden rules of high load kit is one element per lead and make sure it’s a good quality one.

Don’t use it rolled up.

If you can get some to make one for you with good quality kit all the better. There are lots of crappy 13a plugs an sockets on the market. MK plugs seem the best.

Your idea of the 2.5mm extension leads look good. The leads supplied by brewmaster should be up to the job.

 

[Bigcol49]

Hi!
Make up your own extension leads with cable that can handle the current. They won't be cheap.

 

[Grizzly299]

Ooo fault finding, my favourite! Lets take a look.

If as you say you only plugged one element per extension, then you would never have blown the plugtop fuse without L-N or a L-E earth fault. These faults clearing in time to protect the cable depends on the impedance of the circuit, we'll get to this in a minute.

A 13A BS1362 fuse will carry 20A indefinitely without blowing. It requires 1.66 times it's rated current to operate and even then it can still sustain that current for a time . Overload and fault protection are two completely different things.

Thats right people, you still need to load extension leads responsibly.

The way I see it you may have experienced one of two issues;

1. Your appliance or cable suffered a long duration high impedance fault current due to the resistance/impedance of the circuit being too high to operate any of the protective devices, resulting in some very well done cables. With a 13A fuse you could have easily had 25amps flowing for a decent duration, don't have bs1362 time current tables to hand.

If they were carboot sale Chinese extension leads they may not even have real fuses in them, meaning a higher fault current was much more likely.

2. Your extension leads were insufficiently sized for the normal operating current of your appliances, taking into account voltage drop and other de-rating factors. Like being in direct sunlight at the height of summer. This type of overloading usually causes drying/browning and brittleness in cables and accessories over time.


Regarding the first point above, the sequence of events may have been as follows;

1. Insuficient kettle lead over heats melting at the point of connection.

2.Line and earth terminals come into contact with eachother due to the now broken down insulation.

3. A higher current flows in the line and earth conductors, but the current is not of sufficient magnitude to operate any protective devices, due to the high impedance.

4. Thermal withstand of the cable is surpassed and.. well.. melting ensues


Lets take a look at why the kettle lead melted.

The thermal capacity of the connections is such that they are suitable for a sustained load at their rated current at normal operating temperatures. As an example, BS7671 quotes 30*C to be the temperature at which no thermal de-rating factors are applied to cables. The manufacturers recommendations may differ for their products.

When we look at most cheap kettle elements, the kettle lead connects close to the source of heat and heat is transferred very quickly to the connection terminals.
This is not a problem for loads of short duration where cooling occurs between uses, like boiling a kettle.

When boiling 20l of wort for 60 mins the terminals no longer have time to cool and quickly lose the ability to shed heat efficiently, which is why de-rating factors exist.

Take a piece of copper rated at 13A at just 50*C, apply a de-rating factor of 0.71 to its current carrying capacity and we have 9.23 amps, not looking good already. Now go to 80*C and an even lower de-rating and carry on drawing 13Amps and watch things start to melt. Lets not forget that the plastic moulded plugs can only get so hot.


My advice would be to get a competent electrician to carry out an EICR ( Electrical Installation Condition report) at your property and go from there.

Hopefully he'll check that the voltage drop on your ring circuit is within the 5% quoted in bs7681 and that your ring is actually a complete ring and not broken. Which can cause all sorts of issues.

I hope this helps!