SSR vs. DPDT relays

Discussion of the physical aspects
Post Reply
Jcc4507fly
Posts: 31
Joined: Tue Oct 13, 2015 10:43 pm
Bot?: No

SSR vs. DPDT relays

Post by Jcc4507fly »

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-Salo ... 34.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-Signal ... 1e6dbf6250,

http://www.ebay.com/itm/DC-12V-5A-60W-R ... SwNNxWEwA1


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 @ HBT
User avatar
oakbarn
Posts: 846
Joined: Thu Jan 05, 2012 2:28 pm
Bot?: No
Location: Texas
Contact:

Re: SSR vs. DPDT relays

Post by oakbarn »

There are two sides to an SSR.

On side is the Load which is basically like a light switch in a circuit of an Light. It is the wires on the back.

The physical switch that you flip is the control side, In an SSR this is an electronic flipping and that is what the BCS does. The control side is controlled by the Out of a BCS and you can hook up all of the Outs to an individual SSR without an issue.


When you buy an SSR you also need to pay attention to the LOAD side and if it is AC or DC Power, The Electronic Salon Boards available on E Bay and Amazon are great for DC Loads. The Control side still uses an Out of the BCS. The load side would need a power supply, NOT the control side. You would want a 5 vdc control board. It is confusing when getting a board. The Load and Control are different.

I have only used SSRs for the AC Loads. I always use a Higher Rated Amperage SSR than needed. I also use heat sinks because they are easier to mount.
Attachments
15 Amp Box.png
15 Amp Box.png (50.55 KiB) Viewed 3516 times
Jcc4507fly
Posts: 31
Joined: Tue Oct 13, 2015 10:43 pm
Bot?: No

Re: SSR vs. DPDT relays

Post by Jcc4507fly »

The control side is controlled by the Out of a BCS and you can hook up all of the Outs to an individual SSR without an issue.
This is the confirmation I was seeking. Do you see any possible issues with my plans? I will try to put together a schematic for better illustration.
Jcc4507fly
Posts: 31
Joined: Tue Oct 13, 2015 10:43 pm
Bot?: No

Re: SSR vs. DPDT relays

Post by Jcc4507fly »

Here is my Keezer subpanel plan. How does this look?
Attachments
Keezer Subpanel.png
Keezer Subpanel.png (253.06 KiB) Viewed 3494 times
Jcc4507fly
Posts: 31
Joined: Tue Oct 13, 2015 10:43 pm
Bot?: No

Re: SSR vs. DPDT relays

Post by Jcc4507fly »

Should I add fuses anywhere in the panel? I was considering putting a 15Amp fuse on the 110V AC hot leg prior to the hot bus.
Post Reply