Kegerator construction

[Frothy]

mmm tribs hadn't thought anything of it - do the freezers use more than 8A then? I've not got hold of a ranco yet due to temporary bank difficulties :rolleyes:

As you say I was hoping to use the thermostat with my burco boiler too but thats certainly out of the question although I understand that you can get twin thingy ranco thermostats that will control both a heater and a cooling element so I guess its ok for small heaters. I read on a website recently that you can change the relay to one with a higher rating and this guy was using a similar temp controller in this way to regulate his electric dual element mash boiler.

Matt

[tribs]

Well the fridge freezer I was going to use has a 13A rated fuse on it, but I have no idea if this means its unsuitable for a 8A relay, although intuitively, it would appear not. That said typical fuses are 3A, 5A and 13A, so I guess the max current draw could be anywhere between 5A and 13A.

The cole palmer temp controllers relay is rated to 16A and therefore may be a better alternative.

[Frothy]

Pretty much all plugs have 13A fuses on mains right? I just looked on the back of the freezer and its rated
110w & 0.8A @ 220v

although the maths works out even less->
P=IxV
110/220= 0.5A

Should be no problem - they use these kind of thermostats on commercial walk in freezers, supermarket fridges etc.

Wow - ok I might be getting the cheaper cole palmer and wait a couple of weeks for it - if it means I could use it straight on the boiler.

thanks
Matt

[tribs]

I think the problem is the start up current of the motor on the compressor. The compressor on the fridge freezer I am using only uses under 1A but the "cut in current" of the motor is 10.3A :stun

[eskimobob]

Frothy, be careful of using simple Ohms law on mains calculations as in doing so you are assuming purely resistive load which apart from a simple resistive heating element is not going to give you the right answers. Motors tend to present a reactive (somewhat inductive) load and therefore power factor has to be taken into account. Even simple resistive heating elements will have some inductance.

Tribs has the right answer, while the 8A relay should be fine for running the motor, when it closes and the current start flowing, it can be significantly higher than the rated current. As the motor gets up to speed, the current will fall. Similarly when the relay tries to open and break the current, you can get arcing across the terminals hence the terminals need to be rated accordingly.

[Frothy]

now thats something they didn't mention in physics lessons - very interesting. I understand on the analergy that once its the balls rolling it takes less energy to keep it
rolling than to start the motion.

I guess you can measure this using a regular multimeter/ ammeter?

Matt

[Road Runner]

QUOTE (Frothy @ Aug 10 2006, 03:39 AM) I guess you can measure this using a regular multimeter/ ammeter?

Matt
Beware the regular digital multi meters though. They only show a reading every second or so, so you may miss the peak of current draw, as this will only be for milli seconds.

[Western Brewer]

Back on the subject of kegerators, I subscribe to the BYO magazine and in the current issue there is what must be the http://www.alelago.com kegerator. Check it out, there are plans too. When at the site click on 'The Bar'

[BlightyBrewer]

Very nice! B)

..and what a lucky bloke. My SWMBO would never let me construct something like that in the house! :rolleyes:

[eskimobob]

Nice piece of kit that...hmmmm...

Edit: I like the idea of these kegerators but I'm wondering about the beer lines and taps.

I have so far use my cornies for two batches and they have been fine however I have noticed that the beer in the line tends to go somewhat stale. Obviously if the line is short then this is not really a problem as it's only a small quantity in the first pint of a session however with these kegerators you are looking at more like 1.5m to 2m of beer line and you would not want to dismantle and clean between each session.

I've read on here of people squirting Iodophor up the taps after a session to sanitise them although I admit that I didn't bother with mine and seem to have survived unharmed :stun

Any thoughts?

[Frothy]

the beer in the lines would be chilling inside the kegerator?

Matt