Heating Questions

Hi there everyone. Im still pondering on the thought of going electric and putting a heat stick in a keggle. I live in South Africa and over here we have 220v power supply. Is this strong enough to power a 5.5kw heating rod in a 10gallon keggle? How long would it take to bring the water to a boil?

I also see people have temperature controls on their electric keggles. Are these neccessary? I know the wort needs to come to a boiling roar but can a 5.5kw element make it too hot and burn the wort? Can I just boil without any temperature control and manually watch for boil overs instead?

Is there a cheap way of using temperature control like using a device similar to the temperature guage on an urn?

Thanks guys, your help is appreciated.

Yep a 5.5kw element will more than do what you need. That is what most of us use.

dbn_brewer said:

Is there a cheap way of using temperature control like using a device similar to the temperature guage on an urn?

Thanks guys, your help is appreciated.

Click to expand...

It sounds like a PWM (pulse width modulated) element would work for you. This is basically just a simple circuit which drives a solid state relay to cycle the element rapidly on and off with a duty cycle which can be controlled by a rheostat. Here's one thread about this:

https://www.homebrewtalk.com/f170/pwm-show-us-how-221301/

DeafSmith said:

It sounds like a PWM (pulse width modulated) element would work for you. This is basically just a simple circuit which drives a solid state relay to cycle the element rapidly on and off with a duty cycle which can be controlled by a rheostat. Here's one thread about this:

https://www.homebrewtalk.com/f170/pwm-show-us-how-221301/

Click to expand...

So can I just connect my PWM to my kettle just like a switch? Would any PWM be compatible with a 5.5kw element or do I need to put a specific element with a specific PWM in order for is to work?

dbn_brewer said:

So can I just connect my PWM to my kettle just like a switch? Would any PWM be compatible with a 5.5kw element or do I need to put a specific element with a specific PWM in order for is to work?

Click to expand...

The PWM circuit turns the Solid State Relay (SSR) on and off. The SSR switches the power to the element accordingly. The rheostat control in the PWM circuit controls the % of time the SSR is switched on and power applied to the element. So the rheostat acts like a temperature control knob on a stove. The SSR needs to be rated to carry the current drawn by the element (with a healthy margin above that, for reliability). A 5.5 kW element at 220 volts will draw 25 amps, so probably a 40 amp SSR would work. The PWM circuit which drives the SSR needs to be able to drive the SSR and needs to run at a slow frequency compared to your line frequency (50 Hz in SA?).

I don't use an element in a kettle or PWM circuit, but there should be specific recommendations and circuit diagrams somewhere on HBT. I know I have seen at least one schematic for a PWM using a 555 timer chip.