Question on solid state relay for Arduino / Hydra automation (1 Viewer)

[KyleH]

Hello All,

I just started my search on solid state relays (SSR) for the Arduino. I came across the configuration for they Hydra, and I was able to zoom in on the part number for the SSR used.

Why is that that specific part is $30/relay while other relays can be purchased as low as $5-10/relay? If I had to guess the more expensive the relay the higher the amp it can handle. However, if I just want to operate a pump, 50w light bulb/lamp, or koralia pump, can I use the cheaper relay? (maybe put a warning on the plug not to overdo it; is there a fuse in the relays or will it become a fire hazzard if I do not add one?) (Maybe take out the ground plug to prevent the higher end devices from being able to plug in.)

I guess a reef application may install a 500W halogen lamp in any socket, so I guess it can explain using all high-end SSR in the hydra. However, it is almost a savings of $20/relay if you can use the cheaper one.

Is there another disadvantage in using a cheaper relay? (This is just my start on the relay exercise, and it seems there are a lot of references online. I wonder if anyone here can be me an insight on why those relays were used in the hydra project.)

-KyleH

 

[DustinB]

What relays are you talking about? We are only using 2 methods for relay control on the hydra project. My method using the guitar center relay strip and TeraHz's method using some futurlec relay boards.

Are you talking about the other project that actually uses an arduino? Got a link where it talks about this $30 relay?

 

[KyleH]

I maybe getting confused with Hydra and Arduino projects...

Hello Dustin,

Thanks for the quick response. I am looking through the hydra website, and I believe I may be getting confused. I thought the pictures were on hydra because I remember the same guitar center switch used in other diy projects.

In the other project SSR were embedded within the switch, and I was able to get a good zoom of the part numbers to google. I cannot seem to find those pictures on hydra, so I am guessing it was off some arduino diy project with the same switch. (I'll try to find the picture later tonight if I can backtrack my steps.)

Dustin, in the hydra project, I was able to find your participation in the thread. Someone chimed in, and I believe he answered my question in following. Thanks for helping (albeit, months before I had the question! ha!):

"
Guys you are going overboard.
For the last 15 months since I built my first Arduino controller I was using SSRs type Gordos M-OAC5-263 which are rated 3A at 120V. I drive a 1/10 HP chiller, 380W of lights, 30 sec. wavemaker powerheads, etc using independent relays and never had a problem. They don't get hot and I don't have them on heat sinks. See my build thread at reefprojects.com.

Ask yourself what you want your controller to drive and target your SSRs accordingly. Beside most receptacle circuits in US are 15A max. So, careful not to burn your house down !

cheers,
MaLi

PS. I got my SSRs on eBay for $1.5/relay


" (http://www.reefcentral.com/forums/showthread.php?t=1783536&highlight=arduino+build&page=20)

-KyleH