Immersion Element Questions

[Digby Swift]

Thanks Garth, I've given that a good read but confused myself with all the advice.

[Bopper]

Electric's are dangerous, more ways than one! You might be able to use one element on a standand socket, but two would draw about 26 amps...wirring should be kept to a minium...consult a qualified electriction.


Richard

[Digby Swift]

I'm thinking of using two on different rings

[FlippinMental]

Father Xmas has delivered a 100 ltr SS Stock Pot. Now the fun begins... this thread being some 12 months old I was wondering if there are any further views on the merits of fitting immersion elements in preference to kettle. I'm thinking the standard 2x 3kw immersion elements (19758 11" aggressive water) with 2.1/4 BSP flange (6912), and spanner (3803), all from BES, will future proof should I want to increase batch size. there was also some concern over the continuing availability of the cheap asda/tesco elements - so best cut the right size hole, first time me thinks.

the wiring side has been well debated, being stuck with what I've got supply wise (I currently run 2x 2.4 kettle elements off separate 13amp sockets on two separate circuits), I appreciate that I'll be operating at the limits of what the 13amp plug socket arrangement is rated to safely handle.

Grateful for any thoughts/views on how to proceed,

FM

[sib67]

I would definitely go down the immersion heater route rather than cheap kettle elements - far superior IMHO. I've tried both - I used 2 kettle elements in a 33 litre copper, and I've now got 2 immersion heater elements in a 70 litre copper, and 2 in a 100 litre HLT.

As far as power requirements go, I just wired them up to standard 13A plugs and don't have any problems. Of course, the power requirements for a 3KW element are right up to (and very slightly beyond) the rated capcity of a 13A socket, so I couldn't recommend that you do the same.

[FlippinMental]

what elements are you using, the same as listed in my previous or something different again?

[sib67]

what elements are you using, the same as listed in my previous or something different again?

I'm using the same elements - from BES.

[FlippinMental]

thanks for that sib67, I'll forge onward and place an order with BES, and get this baby on the road.

[Garth]

Of course, the power requirements for a 3KW element are right up to (and very slightly beyond) the rated capcity of a 13A socket, so I couldn't recommend that you do the same.

in theory they aren't slightly beyond, they are slightly under, a 3kW immersion will draw 12.5A at 240v

so as long as you're using good quality cable rated at the correct current, (white 16A stuff from B&Q is good, make sure it's the heat resistant stuff) and your house wiring is in good order you should, in theory have no problem, if they are long cables from socket to element, make sure they aren't coiled up when you're using them.

[sib67]

Of course, the power requirements for a 3KW element are right up to (and very slightly beyond) the rated capcity of a 13A socket, so I couldn't recommend that you do the same.

in theory they aren't slightly beyond, they are slightly under, a 3kW immersion will draw 12.5A at 240v

so as long as you're using good quality cable rated at the correct current, (white 16A stuff from B&Q is good, make sure it's the heat resistant stuff) and your house wiring is in good order you should, in theory have no problem, if they are long cables from socket to element, make sure they aren't coiled up when you're using them.

......but it will draw 13.177A at 253V (230V + 10%) - and that is if the 3KW rating is specified at 240V. If the element is rated as 3KW at 230V, then the current at 253V will be 14.348A. I am not sure whether the 3KW rating for these elements is specified at 230V or 240V.

These are rough calculations and do not take power factor into account.

I do agree with Garth though - as long as all cabling etc is in order, I have got no problems with using a 13A socket. Safety inspection type people may have other ideas though.

[Horatio]

[quote="sib67......but it will draw 13.177A at 253V (230V + 10%) - and that is if the 3KW rating is specified at 240V. If the element is rated as 3KW at 230V, then the current at 253V will be 14.348A. I am not sure whether the 3KW rating for these elements is specified at 230V or 240V.

Is that right? I thought you divided the wattage by the voltage to get the amps? 3kw = 3000w / 253v = 11.85A or have I remembered this incorrectly? If not then the problem lies with a reduced voltage, say 230 when it would draw 13.04A. At 240v it draws 12.5A.

I asked my local plumbing shop bloke who said that it may cause problems because an immersion element is not designed for prolonged use at high temperatures (like boiling for 90 minutes). I think enough people use them on here though so they must be fine?

[Andy]

I asked my local plumbing shop bloke who said that it may cause problems because an immersion element is not designed for prolonged use at high temperatures (like boiling for 90 minutes).

Neither are kettle elements

As you said, lots of brewers use immersion elements with no problems.

[sib67]

[quote="sib67......but it will draw 13.177A at 253V (230V + 10%) - and that is if the 3KW rating is specified at 240V. If the element is rated as 3KW at 230V, then the current at 253V will be 14.348A. I am not sure whether the 3KW rating for these elements is specified at 230V or 240V.

Is that right? I thought you divided the wattage by the voltage to get the amps? 3kw = 3000w / 253v = 11.85A or have I remembered this incorrectly? If not then the problem lies with a reduced voltage, say 230 when it would draw 13.04A. At 240v it draws 12.5A.

Current does = P/V, but 3000W is not the power output at any voltage, it is the power output at a specified voltage. At voltages lower than this specified voltage, the current will be lower, and therefore the output power will be reduced. At voltages higher than the specified voltage, the current will be higher, and therefore output power will be increased - of course, if you increase the voltage too much, the element will fail.

You can't use the 3000W as a constant, you must use the element impedance to calculate current flow at other voltages.

Personally, I wouldn't go back to cheap kettle elements after using immersion heater elements, and, as I said before, I have no problem with using a standard 13A socket for them.

[Horatio]

sib67, I though what I was remembering seemed too simple!

I am thinking of using heating elements instead of kettle elements and after reading this I think they seem much better. I have a 30amp feed into my brewing room without anything on it; it has a cable going into a double socket and one coming out/ When it was wired up the spark told me that it was a 30amp ring that I could use to run a number of sockets from around the room if ever I needed to. Do you think this would be okay to run one twin 3k boiler and one single 3k hlt from. I would of course have the sockets added by a qualified electrician.

[sib67]

sib67, I though what I was remembering seemed too simple!

I am thinking of using heating elements instead of kettle elements and after reading this I think they seem much better. I have a 30amp feed into my brewing room without anything on it; it has a cable going into a double socket and one coming out/ When it was wired up the spark told me that it was a 30amp ring that I could use to run a number of sockets from around the room if ever I needed to. Do you think this would be okay to run one twin 3k boiler and one single 3k hlt from. I would of course have the sockets added by a qualified electrician.

You'll have to make sure you don't run more than 2 elements at a time.