Low Voltage Options, VAC or VDC

[fallingsky]

Hi folks,
Jason here with Falling Sky Brewing in Eugene. We are a smallish brewpub in the middle of an expansion from about 1200 bbl to 2500 bbls. Planning on implementing 3 BCS-462s for our glycol control as we are expanding our brewery and I am trying to save money by doing this myself. I am getting a little stuck on selecting what type of valve control to go with. Since I will be doing the wiring, I definitely want it to be low voltage. Here it seems many people go with 12VDC, while in the commercial world 24VDC or 24DAC seems to be the standard. Is there any specific reason for people's apparent preference for 12V?

Also, I am planning on going with solenoid valves instead of motorized ball valves, due to the fact that I will need to use all UL listed equipment (since it is a commercial space) and the cheap ball valves that people are using on their home-brew equipment will likely be a problem when the electrical inspector comes around to sign off my permit. I need 1" NPT for the majority of my tanks' glycol connections. The cheapest UL listed motorized ball valve I can find is $300-350 (Belimo, B2-LF). I can get a UL listed solenoid (Alsco Red Hat, 2/2 8210, 1") for $220, maybe less. If anyone knows of more affordable options that have a UL sticker on them, I would love to hear about them!

Also, it seems that the Alsco solenoids are much cheaper for the 24VAC version than the 24VDC version (like by $100!). Is there really any difference between all these voltage types as long as you get the correct SSR? Are there any pros and cons to consider when deciding between 24VAC and 24VDC?

Thanks in advance, have learned so much just by reading others, and appreciate this community!

Cheers,
Jason

[JonW]

There's no real reason to use any specific voltage of valves. I would say you should standardize on whatever works best for you at the best price. One thing to keep in mind is that depending what type of relays you are using, you may need a power supply for those as well, so you'd likely want to keep the coil voltage of the relays the same as the coil voltage of the valves so that everything can be powered from the same supply. Not a requirement at all, but just something to plan for.

Have you checked if the diaphragm valves can support the low temps you're looking at for glycol? A lot of valves list their max temperature rating, but with glycol, I'd be concerned with the diaphragm material not being pliable at below freezing temps.

[fallingsky]

The Alsco solenoids are recommended by our glycol company, and we actually have had 4 of them in service for 3 years without any issue, so I know they will work. Tho the ones we have are 110VAC so I will have to sell those and swap out, probably for 24VAC from the sound of it.

[fallingsky]

Do you have a recommendation for a 24VAC transformer/power supply that would be capable of running 16 relays and 16 solenoids?

[clearwaterbrewer]

ProBrewer forum would be a much better place for the glycol valve question.

That being said, getting the Electrical inspector to approve a BCS panel could cost you a $1500 UL on-site inspection or more... To pass code, you may have to do something like leave the BCS out until after inspection, and have a 'dummy' temporary box fed from your 24V transformer with simple light switches controlling valves.
(That is the only way I got my BCS in to my commercial distillery, so I do know what I am talking about!)

Be aware that not many code officials will approve a plan with any permanent wiring missing, even low voltage, so you may have to document everything you are doing and have an engineer sign it off... sure, some people do not, but many more have gotten their dreams squashed or delayed, just trying to help you avoid headaches..

If you want a larger 24v transformer, look at landscape lighting or other 24vac transformers... I think the valves draw about 10 watts, so a 250W (or 250VA) transformer would do 16 of them just fine...

https://www.grainger.com/product/DAYTON ... &pbi=4LEF8

Good luck, be safe!