Brewzilla plug warped

[fury_tea]

Had a double brew day in my Brewzilla 3.1.1, and when I was cleaning and went to pull the plug from the socket it was completely stuck. Had to pry it off with a screwdriver. Looks like it has got hot enough to fuse to the socket and warp slightly.

I remember reading a while back that you shouldn't put both heaters on at once, but I always have without issue (until now). Anyone else had this problem?

 

[The Baron]

Am I correct that it has a 1900w and a 500w element in them if so it should be ok in the UK to use it but I would try to use it on a dedicated socket and certainly not on a extension lead if possible.
My Ace has a 2500w element but I do not use it above 2000w for any length of time as it can shorten the life of the element by using it at full power is what I have been advised in the past.
I am sure somebody with more electrical knowledge will advise

 

[Donegal john]

The plug top can overheat and weld to the socket due to normal wear and tear as you are pushing a brass pin on the plug into a brass socket and eventually with the heat created by the elements being on for a long time for the boil they wear. Replace the plug top and the socket and your good for another few brews.
The burning in the socket can also be caused by loose connections in the plug top. So open and tighten every so often as brass expands and contracts under load.

 

[The-Engineer-That-Brews]

My bet would be a loose connection in the plug - those screw terminals can become loose over time, and as soon as you have a poor connection at those kinds of loads it heats up very rapidly.
Agree with @Donegal john that you will need to replace both the plug and the socket I’m afraid. Even better, get a sparky in to fit you a ‘commando’ socket

 

[The-Engineer-That-Brews]

Incidentally, since you are going to be replacing the plug, if you have to use a conventional 3-pin one then try to find one where the posts on the inside are round, with a nut that screws down on top of the cable - like this:

With that type (if you can find one) the connections are less likely to work loose, and the contact area with the wire is larger and less prone to overheating.

 

[fury_tea]

Incidentally, since you are going to be replacing the plug, if you have to use a conventional 3-pin one then try to find one where the posts on the inside are round, with a nut that screws down on top of the cable - like this:
View attachment 65574
With that type (if you can find one) the connections are less likely to work loose, and the contact area with the wire is larger and less prone to overheating.

I just ordered this:
https://www.amazon.co.uk/dp/B000RO1G2U/ref=cm_sw_r_apan_i_N3ATGJVADA276A0VE2C8No images of the inside though.

I have to admit, I've been using it with a short extension lead, I know it's not recommended but there's no plug next to where I have the Robo so I have no choice. It's a rented house so can't start messing with the electrics.

I've been using it like this for about 20 or 30 brews and this is my first issue.

What do you guys think about installing a longer cable on the Robo? I know my way around a soldering iron and I can't imagine it'd be too difficult. I have some heavy duty cable and it would only need to be about 1 metre longer than the original cable.

 

[Donegal john]

I just ordered this:
https://www.amazon.co.uk/dp/B000RO1G2U/ref=cm_sw_r_apan_i_N3ATGJVADA276A0VE2C8No images of the inside though.

I have to admit, I've been using it with a short extension lead, I know it's not recommended but there's no plug next to where I have the Robo so I have no choice. It's a rented house so can't start messing with the electrics.

I've been using it like this for about 20 or 30 brews and this is my first issue.

What do you guys think about installing a longer cable on the Robo? I know my way around a soldering iron and I can't imagine it'd be too difficult. I have some heavy duty cable and it would only need to be about 1 metre longer than the original cable.

That plug top is no different to a standard one except it can be dropped without damaging it loll
As for an extension lead as long as it’s unwound completly then it’s ok.
You can extend the lead on the boiler and a 1.5mm 3 core flex will be good for it. But not really necessary if you do a bit of routine maintenance every so often and tighten all connections. In my 30+ years as a spark the most important thing I have learned is to tighten connections on big load items.

 

[The-Engineer-That-Brews]

I just ordered this:
https://www.amazon.co.uk/dp/B000RO1G2U/ref=cm_sw_r_apan_i_N3ATGJVADA276A0VE2C8No images of the inside though.

I have to admit, I've been using it with a short extension lead, I know it's not recommended but there's no plug next to where I have the Robo so I have no choice. It's a rented house so can't start messing with the electrics.

I've been using it like this for about 20 or 30 brews and this is my first issue.

What do you guys think about installing a longer cable on the Robo? I know my way around a soldering iron and I can't imagine it'd be too difficult. I have some heavy duty cable and it would only need to be about 1 metre longer than the original cable.

I would definitely recommend putting a longer cable on rather than using an extension lead as they are often a bit weedy inside.

For a heater applications, if possible use cable rated '3093Y'; and personally for high loads I like to use cable with 2.5mm conductors. It's a pain to fit into the screw terminals in the plug, but it gets noticeably less warm during a long boil.

https://www.amazon.co.uk/Meters-White-3093Y-Resistant-Flexible/dp/B00BAZ9LCM

I'm told that best practice with high loads is to crimp a 'bootlace ferrule' over the conductor before inserting it into a screw terminal, as it makes a better and more durable joint (but I must admit I've never personally done this). One thing to definitely avoid is tinning the wire with solder before putting it into a screw terminal, as it will work loose much quicker than just the plain copper.

 

[Donegal john]

I would definitely recommend putting a longer cable on rather than using an extension lead as they are often a bit weedy inside.

For a heater applications, if possible use cable rated '3093Y'; and personally for high loads I like to use cable with 2.5mm conductors. It's a pain to fit into the screw terminals in the plug, but it gets noticeably less warm during a long boil.

https://www.amazon.co.uk/Meters-White-3093Y-Resistant-Flexible/dp/B00BAZ9LCM
View attachment 65587

I'm told that best practice with high loads is to crimp a 'bootlace ferrule' over the conductor before inserting it into a screw terminal, as it makes a better and more durable joint (but I must admit I've never personally done this). One thing to definitely avoid is tinning the wire with solder before putting it into a screw terminal, as it will work loose much quicker than just the plain copper.

2.5mm in a 13a plugtop is overkill. Especially when the boiler is only 2.4kw ie 10amps. A 1.5mm flex is rated at 16a. More that capable of running the element for an hour boil.
My hot tub is 3kw and is on an1.5mm flex.
If 2.5mm is hard to go into the terminals of a 13anplug top it’s for a reason.

 

[fury_tea]

I think I will use a longer cable, it's not much extra work than changing the plug and it'll be piece of mind.

Pretty sure the cable I have is 1.5mm. I bought it a while back for a project that never came to light. I'll probably use that.

Thanks for the help, I'll be sure to maintain the plug from now on.

Cheers

 

[RoomWithABrew]

@fury_tea
I notice that you plugged into an extension lead. Many of us using robobrews, brewzillas etc with 2500 or 3000 watts no problem.

I would build or get a decent extension lead, when I charged my electric car via an extension lead that was fully unwound with the socket in the middle of the windable cable drum it melted together much as yours did. The issue was with the socket not the plug.
Appreciate you might need a new plug a 13amp plug should easily suffice.
Build yourself a higher quality extension lead with decent cable on it no longer than needed and wire it into a 13 amp socket with external mount box on it you should be fine then.
You'd be better to have that socket overheat on your new extension lead than the landlords socket that you are accessing via an extended brewunit cable.

 

[The-Engineer-That-Brews]

2.5mm in a 13a plugtop is overkill. Especially when the boiler is only 2.4kw ie 10amps. A 1.5mm flex is rated at 16a. More that capable of running the element for an hour boil.
My hot tub is 3kw and is on an1.5mm flex.
If 2.5mm is hard to go into the terminals of a 13anplug top it’s for a reason.

Heh - yes OK I just ran the numbers: on a 5m cable with a 13A load I reckon you get 20W of cable heating at 1.5mm and 10W at 2.5mm … so 2.5mm is probably a bit overkill (but I find it reassuring LoL)

 

[gyurmaember]

Heh - yes OK I just ran the numbers: on a 5m cable with a 13A load I reckon you get 20W of cable heating at 1.5mm and 10W at 2.5mm … so 2.5mm is probably a bit overkill (but I find it reassuring LoL)

And there's the point. Not overkill at all.

 

[gyurmaember]

@fury_tea the other thing you can do, as you gonna replace the socket as well, make sure it's on a ring circuit. If not, choose an another one for brewing purposes. Also worth to upgrade the power lead of your kettle, the voltage drop can be huge(therefore it draw more current) on those thin wires provided.

 

[The-Engineer-That-Brews]

upgrade the power lead of your kettle, the voltage drop can be huge(therefore it draw more current) on those thin wires provided.

Actually the same load connected by a thin cable will draw less current; but it's correct to say that the voltage dropped across the cable (and the power dissipated in it) will be higher.

 

[gyurmaember]

Actually the same load connected by a thin cable will draw less current; but it's correct to say that the voltage dropped across the cable (and the power dissipated in it) will be higher.

It'll draw more current due to the voltage drop.
That's why we have to increase the cable diameter with the length.

 

[The-Engineer-That-Brews]

It'll draw more current due to the voltage drop.
That's why we have to increase the cable diameter with the length.

Sorry to contradict you, my friend, but that's not quite right :-)

The cable and the load form a series circuit (see diagram); so the total resistance of the circuit is R = rL + 2 x rc
Now to get the total circuit current we just use Ohm's Law: I = V / R
So if rc increases (longer cable, thinner conductors etc), then R gets larger; and of course V remains the same (240V).
Therefore for a longer or thinner cable, the current drawn from the mains, I, gets smaller.
This also follows intuitively: imagine using a very high resistance cable (say rc = 1MΩ). You would rightly expect the current drawn from the mains to be very low.

The reason you might need to use a heavier duty cable if rc increases, is because the power dissipated in each conductor of the cable (due to Ohmic heating) is isquared x rc.
If you work this out using the above formula for i , and assume that rc << rL, you will get this power as (V / rL) squared x rc (see below).

So if you double the length of the cable (or halve the conductor cross-sectional area) then, regardless of the fact the current is lower, you lose twice as much power in the cable.

Note in fact that as you increase the length of the cable, the power dissipated per metre remains roughly the same, so the surface of the cable doesn't get any hotter... UNLESS it's all grouped together on a cable reel ... which is why extension reels tend to melt if you don't fully unreel them.

 

[hoppyscotty]

Been using my brewzilla (and a mates at his place) happily for over a year using both elements with no melted plugs, even with mine where I use a 5m extension lead.

We recently switched to only using one element during the mash and boil when I happened to be looking at the instructions and I read that with the malt pipe in place you shouldn't run both elements at the same time (might have even said only use the 500w element). So now I heat up the strike water with the malt pipe out, put in the malt pipe and use the 1900w element to bring strike water back upto temp, and once mashed in and temp stabilised switch to the 500w element which I find to be good enough to maintain mash temp even through the winter (brew in a garage with the door open). Then when the malt pipe is pulled I'll use both elements to bring to the boil and again find the 1900w element is fine to maintain the boil.

 

[fury_tea]

@The-Engineer-That-Brews

I have some rudimentary understanding of electronics but you lost me after Ohm's Law. That's a bit too technical for me! Maybe one day I'll be able to understand that, and maybe one day I will be able to speak Mandarin too.

@RoomWithABrew

If I understand you correctly you're suggesting I wire into a pattress box and socket, mount it on the wall, then run a cable to the existing socket and plug it in via 13a plug? So essentially creating a wall mounted extension lead?

I do like this idea, as it seems a pretty neat way of doing it and like you say it's my own socket, not the landlord's, that melts if this happens again.

Could I have a double gang plugged in or is that pushing it?

I need my overhead extraction fan running at the same time as I boil or else I'm creating a garage sauna.

 

[RoomWithABrew]

@fury_tea
I've just educated myself as to what a pattress box is and yes I'm suggesting use one of those. No need though to mount it on the wall as it's a sealed unit ( not IP65 ) you can have it close to your brewzilla. You will get more cooling of that box if one surface isn't screwed to a wall.
Regarding double gang you'd need to look at the amps and as suggested above the load on the circuit that it's coming from. Depends on the extractor fan current draw.
FWIW a condenser is the best way to control the steam, it's quiet, generates some warm water for cleaning, cuts down boil off loss and power needed to boil. You'd possibly be able to boil with the 500 w element if you have an insulated brewzilla.
Short circuit brewing has a how to build one.
Mine I built for Guten 70 so a bit bigger than for a 35litre but I brew indoors and now don't have to wash the walls and ceiling down in the brewery,wife still calling it the laundry when will she learn?