Wired PID Controller

[Andy]

Are you saying you're looking to power a 4500W element from a 13A outlet ? That's a no-no. Regardless of how you upgrade the downstream wiring, the wall socket (assuming it's a conventional domestic one) isn't designed for that kind of load.

[Rhodesy]

I had a feeling that something didnt add up. Suppose the question is, assuming I sort out my problem with the element power (18 amps) going to the thermostatic controller which is 30A rated. Will the controller de-energise the connection to the wall socket to be within the 13A requirement?

Aplogies for what may seem like simple questions.

[orlando]

Are you saying you're looking to power a 4500W element from a 13A outlet ? That's a no-no. Regardless of how you upgrade the downstream wiring, the wall socket (assuming it's a conventional domestic one) isn't designed for that kind of load.

Is it a low density element too? These things can burn out very rapidly if the flow is interrupted?

[BenB]

The controller won't down regulate the power (at least not on the basis that you've plugged it into a 13a supply. You'll be pulling 18 amps (approximately) for which you'll need an industrial plug and socket. And an adequate supply. Your socket might be on a 2.5mm spur which would only be able to cope with 16 amps maximum (and even then only assuming it's not down-regulated by insulation, plaster etc etc). If you try pulling 18a via a 2.5mm spur you risk letting out the magic smoke (which in the case of domestic wiring is a bad thing). Think house fire. 32A plugs and sockets are available but if you know how to use them you know where to get them

I've got 13A plugs which get significantly warm when pulling 13A (despite the wires being properly terminated etc). I hate to think what would happen if you pulled 18a via some of them!

I'd stick to standard 13 amp plugs (and therefore ready installed sockets) and make sure the supply is protected by a RCD and MCB and not old fashioned fuse wire.

[Fil]

why such a big element?? my hlt and boil kettle are fitted with 2 elements, each one supplied from a seperate 13a source. you can control the power easily enough by incorporating a 2nd relay in your control solution to issolate the 2 seperate feeds.

the multiple element solution may be a lil more expensive to buy and a lil more complex to install and control, but it provides you with a little protection against element failure letting you limp to the end of a brewday should you loose one.. And provide a very simple method of power control with 2 power settings ( 1 element on or 2 elements on)..

Its a tried n tested method just remember to keep discrete sourced power supplies issolated within the control solution.. for exaple i use a pid and it fires 2 x ssrs i have one element powered throu one ssr and the 2nd through the 2nd, and the control box has 2 x power in plugs..

fwiw i also source my power via fully unwound hi amp extention leads from 2 seperate ring mains as to not impact on general electricity use.. puling 6kw or 24+Amps off a single ring may limit waht else can be used durring the brew period before the ringmain protection trips

[lord groan]

Agree with comments above, you cannot safely pull 18.75A through domestic switches, sockets and wiring. You'll destroy them, and quite possibly start a fire. I'd use a switch rated at 20A or more not 13A, you're pushing 2.5mm twin and earth if you carry 18.75A through it, although in the right circumstances you might get away with it, I'd go for 4mm cable to be safe.

I'd go with what Fil suggests if you can - 2 elements rated around 2500w-3000w individually supplied from separate ring mains, I run mine off my shed (1 element) and my downstairs ring main for the other these have separate MCB's in the house consumer unit

[BenB]

I like having two elements but two extension cables would be a nuisance (I brew in the shed (no electricity) at the bottom of the garden). So I've got 2*1500w elements. Works nicely so far though only doing 5 gallon batches....