Which relays for BCS... SSR vs. DPDT

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jcc4507fly

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I've been reading here and else where on the web and think I have a grasp just want some confirmation. I'm looking to expand my BCS-462 usage from just the hot side of the Brewery to also controlling my Keezer & also my ferm chiller. At this point I intend to add 3 relays, one for Keezer compressor, one for Keezer fan, one for glycol pump. I plan to run 3 temp probes over Cat5 about 50-60'. I also plan to run the 3 BCS outputs and the BCS ground in another run of cat5 the same distance. The 2 ethernet runs will join up in an enclosure on the other side of the garage. I intend on having 3 female panel mount RJ45 connects for the temp probes, 2 fermenters and the keezer. I plan on wiring up 4 receptacles (only 3 will be in use for now) that will be assigned to a specific device/function as per the relay that is controlling them. I figured I'd need at least a 25Amp SSR for the Keezer, which is rated at less than 10amps. A 6 amp for my fan, which is rated at 2.8amps. And a 6 amp for the pump which is rated at .25 amps.

Deciding which relays to use. From what I understand I never want to use the BCS 5V to power ANY relay, only use it for DINs. If I use a DPDT relay similar to this; http://stores.ebay.com/Electronics-...75401119&_sid=804830199&_trksid=p4634.c0.m322, I will need a 5VDC/12VDC (depending on which board I purchase respectively) power supply to power the relays. And the respective BCS output will be used to "switch" the relay. So if I went this route for the fan and pump I'd need a 2 channel relay, and a power supply. Both listed here:
http://www.ebay.com/itm/Two-DPDT-Si...no-8051-AVR-/130690277968?hash=item1e6dbf6250,

http://www.ebay.com/itm/DC-12V-5A-6...363519?hash=item4af1fb61bf:g:3SEAAOSwNNxWEwA1

On the other hand, I have 2 10amp SSRs that I could use for the fan & pump. Then I could order a 25amp SSR like this one for the Keezer compressor. Then hook up the BCS output to +DC on the SSR, and one of the 3 BCS Grounds to the -DC on the SSR. Then the Hot/Black would be hooked up on the AC side of SSR. Essentially eliminating the need for a power supply. Is this correct?

Is it correct that each BCS output is capable of 5VDC and 20mAh, so as long as the relay is low switching, like the SSRs listed above, I could safely put an SSR on every BCS output and not worry about damaging the BCS? Is it ever necessary to add a separate power supply when using DC to AC SSRs? As for another possible option do these/and these work the same way that their larger FOTEK cousins do in that they can run off the BCS output without a power supply?

If everything above is correct I'm thinking for simplicity and size of WHOLE package that appropriately rated SSRs are the way to go since they don't require a power supply. And since I have a few laying around.

Thread at BCS Forum
 
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Here is a sketch of what I was thinking. I was thinking that I should put fuses in the panel. Any suggestions on where? I plan to fuse the BCS output legs with a low amperage fuse maybe .5-1.0 amp, just in case there was a short with the line voltage to prevent 110V from traveling into the ethernet cable or back to the BCS. I also considered fusing the line leg between the SSR's and the receptacle to provide a fail safe for the individual components. Another thought was to just fuse the line leg as it enters the panel but prior to the hot bus. Thoughts?

Keezer Subpanel.png
 
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