Element tripping out mains.

[PaulC]

Hi all

Don't know if you can help but I have an electrim element and thermostat which I fitted to my 60 litre bucket to act as my HLT. Its been working fine until just recently but the other week when I switched it on, it tripped out the mains. It had some carbonate build up on it and I thought that might be the cause so I gave it a soak in a hot acid solution which cleaned it up a treat and it worked fine for one batch but now it has done it again! Has this happened to anyone else and if so, do you know how I stop it from tripping the mains?

Paul

[farleyman]

Sad to say but Daab is exactly right .
The cut out can be removed but it is an extremely delicate task and usually results in wrecking during the first attempt.
In my experience the 2.4 kw. kettle elements are more susceptible to trouble than the larger 3 kw. ones fitted to Burcos.
I have two boilers, ome with the kettle element for worts of 1050 and under viz. the 2.4 kw. and a 3 kw. Burco for stronger worts.
I find this system to be trouble free, up to now.
Also in both units I run plain liquor into the boiler prior to sparging so
that concentrated wort does not come into contact with the element
thus allowing the power to be turned on when sparging commences
so reducing warm up time.

Cheers Tom

[Graham]

...but the other week when I switched it on, it tripped out the mains.

Can you elaborate as to whether it is the mains trip at the fuse box, or the safety cut out on the boiler.

If it is the fuse box - distribution board trip:
Is it RCD or a simpler type?
What rating is it?

[PaulC]

Thanks for the replies so far guys. Just to clarify, Its just water I'm heating for the sparge, not wort. And its the mains, as in the fuse box on the wall in my hall thats tripping not the 'stat on the HLT. Honestly don't know what type of box I have on the wall or the wattage of the element.

[Graham]

Thanks for the replies so far guys. Just to clarify, Its just water I'm heating for the sparge, not wort. And its the mains, as in the fuse box on the wall in my hall thats tripping not the 'stat on the HLT. Honestly don't know what type of box I have on the wall or the wattage of the element.

Well it is nothing to do with scale on the element then, and nothing to do with the wattage of the element.

You wouldn't be capable of tripping a 30A trip with a 3kW heater unless you have a short (or have something else pretty hefty running on the same circuit at the same time).

It is more likely a fault.
You can prove that trip itself is okay by plugging something around three kilowatt. like an electric kettle or a fan heater into the same socket. If it doesn't trip, then the fault is with your electrim heater or wiring.

You may have a short, either in the wiring or a faulty element if you have a conventional trip.

If you have an RCD type trip, then a bit of moisture in the connections can cause it to trip.

It is time to examine the connections for integrity and to ensure that they are dry.

Do you have a multimeter that can measure resistance?

[steve_flack]

I concur with Graham. I had one of the immersion heater style elements in my boiler suddenly start tripping the fuses the instant it was turned on. For whatever reason it was knackered and as soon as I replaced it I had no problems (and still don't).

[edit1now]

You can test the element and lead with a cheap multimeter like this from Maplins. Unplug the lead from the mains! If you measure from the live to the neutral pin it should read about 30 ohms for a 2.2kW element, and if you measure from live to earth or neutral to earth it should read infinite resistance (my multimeter reads about 1400 mega-ohms for "infinite"). Significantly less than that from live or neutral to earth would suggest some degree of shorting, which will throw an RCD in your consumer unit.

[scarer]

I had a slightly different issue when I first started, My equipment is all set up in my conservatory and there are no mains in there so I ran a 4 way power strip into the conservatory from the living room.
All was going well as I only had my Electrim going which was thermostatically switching itself on and off to keep the sparge water to temp. The electrim has a 2Kw element.
Then I started up my 3Kw Burco to start the boil, leaving the electrim on. Everything was fine for an hour and then something blew.
The power strip had given up the ghost, unsurprisingly. I had been aware of what I was doing and had been periodically checking the plug socket for heat but I had left it too long and forgot about the Electrim.
The double socket in the lounge which also had a fridge freezer plugged into it was extremely hot and I had gotten off lightly I think.
It doesn't take much to overload these sort of extension leads and I often wonder if people that have fitted 2 elements into their boilers ever have problems, and do people check the electrical ratings of equipment to see if they're working safely.
Kitchens, I believe are on a separate high rated ring main but how much can a double socket stand and the wiring between them in the wall?

[sib67]

Cookers have a seperate ring but kitchens don't (or didn't used to).

Double sockets can't take 2 elements, technically depending on how you choose to calculate the figures they can't even take 1 x 3kw element.

3000w/220v = 13.6a and wall sockets are rated at 13a so you should use 2 seperate outlets. It wont blow the main fuse though unless there is somesort of fault unless there's loads of other stuff running at the same time maybe. The draw would be pretty high if the washing machine, tumble dryer and refridgerator were all running at the same time as 2 or more kettle elements, that should be more than enough to exceed the 30a fuse/trip.

UK mains voltage is now 230V (+10% -6%), so, not taking power factor into consideration, the current would be 3000W/230V = 13.04A - only very slightly over the 13A rating.

[Jim]

Really, it depends more on the voltage rating of the element itself. An element rated 3kW at 230v will take 13.04 amps when you put 230v across it. However, the same element will take slightly less if you put 220v on it. It's all to do with the impedance of the element.

[PaulC]

Thanks again everyone, lots here for me to go on. I have a re-setable trip so thats not a problem, I'll go through all your suggestions and find the cause, and let you know what it was. Thanks again.

Paul

[sib67]

Really, it depends more on the voltage rating of the element itself. An element rated 3kW at 230v will take 13.04 amps when you put 230v across it. However, the same element will take slightly less if you put 220v on it. It's all to do with the impedance of the element.

That's right Jim - at a lower voltage you're not going to get 3KW, so the 3000 figure becomes irrelevant.

If the element draws 13.04A at 230V then we can call the impedance 17.64 ohms (230/13.04) - assuming a purely resistive load.

At the lower mains limit of 216.2V (230 - 6%), the current will be 12.26A (230/17.64), and the power will be only 2.65KW (12.26*12.26*17.64).

At the upper limit of 253V however (230 + 10%), the current will be 14.34A (253/17.64), and the power will be 3.629KW (14.34*14.34*17.64).

Again, the above calculations do not take into account power factor, so assume a purely resistive load.

[PaulC]

Hi all

Just an update on this. Its been a while I know, but I've not been brewing until last night. I took the cover off the Electrim thermostat and found that it was a bit gunky inside and that there were signs of scorching on one of the live leads. I decided to bypass the thermostat completely and hey presto - no cut-out! I'll continue to use it like this until I can get a proper temperature controller to do the job. Will an ATC 800 be okay for this?

Best regards

Paul

[Graham]

Hi Paul,
An atc800's range is 5-40 deg c so no good for controlling the temperature of a boier, mash tun or HLT.

It also will not handle the current without a slave relay.

I didn't realise that ATC800s had such a narrow range. That explains why someone on here, forgotten the name, was designing a replacement. I was a bit puzzled at the time, but it falls into place now.

[PaulC]

So I would need something like a PID for bringing up to and maintaining sparge temps?