Control Boxes!

[Darcey]

Hello! I have been hijacking several threads for the last couple of weeks trying to get my head around building an all in one control box for HLT, MLT and Copper control. (HERMS is staying away for now as I can fit it in to my brain).

This is what I have so far.

3x

PID's I dont need three but I have them so I may as well use them.
2x

PT100's (3rd in post)
1x

enclosure
1x

heatsink
I also have 3x switches to turn off elements and 3x LED lights to show they are running (for abit of bling)
The PT100's are going to be wired up to the enclosure using XLR adaptors

Only out of a postal error am I using the PID's as expensive temperature gauges one will power the 1x2.75kw with SSR for the HLT the other two will be used to measure the temperature of the MLT and the Copper (and one may end up as a HERMS but as I said.. I am not thinking about that at the moment).

Should I wire the 3 PID's to the same power source as only one will be switching an element which will be isolated on the elements live wire when HLT is not required? The other two will only be monitoring the temperature?

The 2x2.75kw boiler elements will be fed from a dedicated ring I am having installed in the cellar to cope with the demand (however untill that is finished I shall be using extentions to run from two different mains rings in the house. These elements are to be fused at a wall box before being switched at the control box. Should I run 2x power feeds to the control box for switching or should I just be running the live wire to the control box to switch it?

Before everyone explodes with ratings and various electrical statues I should point out that a qualified electrician will be assisting me in building and signing off as well as testing the equipment before I plug it all in. I am only gathering together a plan for building a control box.

Please feel free to share any information or advice you may have.. also any pictures they help as well.

If this all becomes too difficult (or dangerous to do) I shall just do the original plan and have 3x enclosures and do it all separately.


D

 

[Aleman]

D

I have an independent power supply to power the PIDs, and other electronics, Running through a time switch.

Each PID controlled element has it's own separate Power in and power out plug and socket . . . While with only one PID in use you could run everything off of one 13A input feed (the SSR having its own output socket), it might be worth considering future requirements and planning accordingly

 

[Northern Brewer]

I haven't completed the thinking on this one yet but I have a 32 amp breaker feeding the barn so ideally, as each 2.75kw element draw about 12 amps at 230v (worst case voltage) then I only ever want two elements on full blast at any one time. With 2 in the HLT, one in the HX and two in the boiler I was thinking of putting two 15A MCBs in the barn consumer unit and feed each of these to the control box seperately to a big 32A+ amp rotary switch so I can have different themes something like "HLT preheat" with both elements, "mash" with one HLT element and the HX, then boil with both elements in the copper. I found some big switches from China like these and there are others similar.

Not sure if this will work yet as there is not much detail with the switch on the web site.

 

[Darcey]

My as at the moment I have only 3x2.74kw elements which at any one time only 2 will be on full blast I am having 2xMCB's installed to power the boiler elements and run the HLT single element on the cellars socket ring (with all the FV fridges and Kegerator switched off for the warm up at least...me thinks). for now the elements are run HLT - Cellar Sockets - Boiler 1 & 2 from different ones in the house how ever I could get away with having the second element on the cellar sockets as I only use one element untill the sparge is fully done ie the HLT is off. This would prevent me from doing double brewdays.. but I have lots of days free with the house to myself so I am not going to worry about that!

 

[Vossy1]

As Tony has said, it would be better to consider potential upgrades in the future when wiring your control box. I have 2 x element driving PIDs but one of the feeds also supplies the 3rd temperature displaying PID, as you've pointed out, there's no real draw on that PID so why have it's own supply. Having said that if either of those PIDS goes down it could take the other one with it, unless you've spurred and fused the individual PIDS at box supply entry

As above you might also consider fitting in-line fuses to the PIDs L supply, it doesn't take a lot to blow them :shock:

 

[shocker]

Darcey , I put this reply on one of your hi jacks but it may be more appropriate here.....

Self adhesive cable tie anchors ? Those square things with sticky one side and slots t'other ? Like this ...

http://www.tlc-direct.co.uk/Products/CTB20.html

....??

I am not up on the high-tec bits like Ale-y and UP and the others but I would have thought that a 12vDC pump could be driven with a velleman kit variable power supply which would fit into a panel nicely or one of the units sold for amateurs tattooists , thus....

http://www.ebay.co.uk/itm/Pro-Tattoo-Re ... 2560wt_877

They generally have a 6mm jack on/off switch socket for a footswitch and another jack for output . I have had quite a few pass through my hands and they arent too bad at all . A little fettling could fir the unit into a panel or better , remote the pot into the panel so the unit can get some cooling .

 

[shocker]

Also , the style of chassis XLR you show is the one I would choose as the male and female have the same panel footprint/cutout so are easier and neater to fit .

 

[Darcey]

thanks for the replys! I have just spent half an hour trying to drill out a hole for the first PID, I'm a bit rusty with the Dremel.. not quite as straight as I had hoped! :shock: I started to get angry so I put it all away and will return to building the enclosure soon enough!

I have checked the cellar electrics and the lounge and cellar sockets are on a 32amp breaker as is the rest of the house apart from the lights which are on 6! (explains why the electrics trip when a bulb blows!).

I'll get there soon enough. Plenty to be getting on with. Which quick fuses for inline would people suggest?

d

 

[Vossy1]

thanks for the replys! I have just spent half an hour trying to drill out a hole for the first PID, I'm a bit rusty with the Dremel.. not quite as straight as I had hoped! :shock: I started to get angry so I put it all away and will return to building the enclosure soon enough!

:rofl: ...you're as bad as me :lol:

 

[Nunfa1]

Just a quick question, not really a hijack as it's quite relevant, but why do people tend to use SSR's as opposed to standard contactors?

 

[Northern Brewer]

Just a quick question, not really a hijack as it's quite relevant, but why do people tend to use SSR's as opposed to standard contactors?

Hi Nunfa1

I believe its that PIDs work with SSRs, the instructions tend to list a SSR output at least mine do, but not conventional relays. Not sure it its current draw or the amount of pulsing that the PID does when keepng a constant temp.

I'm looking for a timer for my control box and have found these they are the same physical format as the PIDs I use but have two models, one for SSRs and one for conventional relays so the relay requirements of each realy type must be different. A timer won't pulse like a PID either, just on or off.

Just a guess, may not be correct, I haven't fiddled with these until I looked in HERMs

Cheers
NB

 

[Nunfa1]

The pulsing would be an issue, SSR's deal with very fast switching better than contactors, the downside to that is the heat produced.
What do you want the timer to control?

 

[Northern Brewer]

What do you want the timer to control?

Initially I was just looking for a simple timer, possibly a kitchen timer with a magnet to stick on the front of the control box for timing mash/boil etc. However now I have seen the timers I mention above then I'm thinking of other things I can do. They will look neat if I just use them as a timer as they are the same form factor as the PIDs however the dual relay contacts do open possibilities. Can't seem to buy the SSR version though however this may not be important.

 

[Nunfa1]

I don't see why an SSR output would be different from a relay output on the timer, just make sure the coil voltage of whatever you use is rated the same as the output. Apologies if I'm telling you stuff you already know.

 

[Northern Brewer]

I'm no expert on these so any advice gratefully received :thumb:

The PID alarm output can trigger the timer to start so I'm thinking that the boiler could be automated by a PID turning off one of the two elements when boiling is reached then the alarm output starts the timer. Not sure if I would use the timer to turn the boil off after the timer period but its possible.

 

[Nunfa1]

Lol, I think we're getting into hijack territory here. I'm not sure how using the PID to turn on the boiler will help much though.
That switch you linked to earlier in the thread, the same thing could be done quite easily with relays instead.

 

[Northern Brewer]

True - need to think about this over a couple of beers first. : Initially I was just going to use the PID and probe in the copper purely to measure the temp when cooling with the plate chiller however automating turning one of the two elements off when it reaches boil was in the back of my mind and its a short leap from there to get ther PID to trigger the timer to measure the boil time as it turns off the element.

Edit - BTW, the difference between the conventional relay and SSR output types is that the PID or timer with conventional relay output has built in relays of typically 3A current rating and provide both NO or NC contacts while the ones with the SSR output provide a voltage output, typically 12v I believe.

I've bought a timer from HK to play with, aim is to just start the timer as the wort gets to the boil. Could use the relay output from hte timer to turn my tractor on and operate the hydraulics to tip the hops into the copper :grin:

Cheers
NB