Help with SSR and Arduino

Hi guys,

As part of my project, I need to connect a 230V ac motor to an Arduino mega. What should do the work is a solid state relay. I have seen some videos on youtube on ssr’s connected to arduino. I know this might not be the case but all the relays which were used proved to be much larger than the one I have got from ebay, so I was thinking that this might actually burn the ssr and microcontroller. I was wondering if someone can have a look at the attached specs of this ssr and tell me if I could use it for my project. The motor I’m using has a voltage of 230V and a current of 0.9A.

The specs can be seen in this pdf:

http://www.google.com.mt/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CGAQFjAA&url=http%3A%2F%2Fwww.te.com%2Fcommerce%2FDocumentDelivery%2FDDEController%3FAction%3Dsrchrtrv%26DocNm%3D108-98005%26DocType%3DSS%26DocLang%3DEN&ei=FhipT_CZAYfqOfHyraAD&usg=AFQjCNGAaq4fEDLPobxjjc13DGf2qD3-lw

SSR.pdf (906 KB)

The PDF attached was not for a SSR but a mini relay rated at 60w far to small to run a 200w motor. You normally want a good deal of margin for an inductive load for that motor I would want something 4 amps or better at 230v. 5v relays that can handle 10amps are rather inexpensive and there are plenty of little boards that bundle the relay transistor etc so you can run it directly off a io pin.

Thx silasmoeckel,

I was thinking about this ssr: http://www.gavazzionline.com/pdf/rp1a48d5.pdf

But since you recommended more than 4A I think it is still not suitable.

I am not an electrical type of person which is why I might sound as a total idiot in this subject.

The AC53a can handle upto 5A. What motor are you running?

I just completed a project with a SSR. It was used in an off-road vecihle. It worked great. I had one problem. Unlike a regular relay where the polarity on the input doesn't matter, the polarity in a SSR does matter. On the inside there is a led which will only turn on when voltage is applied in the correct manner. If not, a limited amount of current will flow, but the led won't illuminate (nature of the led) and you might think the SSR is working. In which case you might spend 4 hours trouble shooting the problem. Moral is, wire it correctly.

If you don't mind the shipping from China, this sot of thing is widely available on Ebay :

http://www.ebay.co.uk/itm/Solid-State-Relays-SSR-10-DA-DC-Output-24-380V-AC-10A-/230778638964?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item35bb7a9274#ht_3024wt_1398

Way over spec might make up for its dubious origins..........

A solid-state relay is usually the best and the easiest solution for an AC motor. A regular-mechanical relay might be cheaper, but it's usually going to require a driver circuit for the coil, and it's going to eventually wear-out.

I was thinking about this ssr: http://www.gavazzionline.com/pdf/rp1a48d5.pdf

That looks like it would work. Motors can be "nasty loads" (inductive), but that relay is rated for inductive loads so you should be OK.

Worst case, you fry the SSR... Since relays are isolated, if you overload & burn-out the SSR, your Arduino won't be damaged! :D

When someone says "AC motor" and "SSR", I think of something like [u]this[/u], but that's overkill for your ~1A motor.