Hi everybody!
Today my relays crashed and arduino with them. I can't find any good reason why it happens. I was blinking few 400W halogens and then house fuse burned. I looked relays and arduino and they smelled very bad and some places in relayboard was dark. Have you any idea why this happened and can I repair my arduino or does the warranty compensate it?
Best Regards Elias
the warranty ? XD
I wonder if it is a joke or a serious post 
the regulator didn't like the 220V, I guess 
I suspect a short happened, which caused all of this.
do you have a schematics of your stuff ? a photo taken before the magic smoke ?
No that's not the joke. I can't understand how 220 volt get to arduino, because everything worked many hours before magic smoke happened. So I want to know how 220 volt get to arduino and why wires and transistors between arduino and relays looks fine? Here is one pictrue from the stuff.
Blinking halogen lights is not a good idea. The resistance of a halogen lamp when cold (i.e. when you first turn it on) is about 1/14 of its resistance when hot. So it takes a current surge of 14x the normal current when you first turn it on. This implies that your 230V 400W halogen lamp will take 1.74A when hot but a surge of 24.3A when cold, unless the lamp or lamp fitting has a surge limitation device in it. You don't want to be doing this very often, you will wear your relay contacts and the lamps.
Are you saying that the Arduino is no longer working, even with the relays disconnected?
PS - in the photo:
You should separate the mains wiring from the Arduino wiring much better than that. For example, put the relay board in the middle of an enclosure. Then put only mains components and wiring to one side of the relay board, and only low voltage components and wiring to the other side.
There appears to be a scorch mark on the ice cream tub. Is there a corresponding scorch mark on the underside of the relay board?
Were you using a open face power supply to provide power to the arduino? How is it connected to AC? Is the power supply working now, or burnt also?
dc42:
Are you saying that the Arduino is no longer working, even with the relays disconnected?
look at the 1rst photo, I think the answer is there
alnath:
dc42:
Are you saying that the Arduino is no longer working, even with the relays disconnected?look at the 1rst photo, I think the answer is there
The photo attached to the original post wasn't showing when I looked at this thread before. Looks like the voltage regulator has been killed, probably by a transient from the power supply. What sort of power supply were you using to power the Arduino?
eliasojala1234:
No that's not the joke. I can't understand how 220 volt get to arduino, because everything worked many hours before magic smoke happened. So I want to know how 220 volt get to arduino and why wires and transistors between arduino and relays looks fine? Here is one pictrue from the stuff.
As DC42 says, a lot of amperes go through the contacts and the wires when the lamps are cold, and your wires are close.
If some wires got hot and a naked part touched an arduino (or a coil ) wire...... magic smoke.
Given the fact that a fuse burnt, and relays and arduino reg. too, there is no doubt a main power wire went in contact with a low voltage part . With a lot of wires and connexions, it is easy to do something wrong ( a loose connexion.... )
Just 2 preliminary guess:
Not enough info yet for a more informed guess.
I used computer power supply and it is working now (or at least it's fan is working)
I disconnected relays and any other components from arduino (so arduino is now like in original packet) and I tried to download blink, but it didn't work.
I looked transistors and low power wires and they seemed good, but I didn't test them yet.
I also used led strips and few small leds and they seems good. Why high power didn't get to them?
Under the relayboard and it's plasticbox there is breadboard with transistors.
If 220 volts destroyed the regulator do you think I can change the regulator and then arduino works? Or is the arduino destroyed at all?
And for the future: If I use SSR and fuses between it and arduino is then safe?
Looks like you had a short on the relay board between one of the 230V contacts on the last relay and the supply rail on the relay board. Perhaps jackwp was right with his guess #2.
So can't I repair my arduino? And in the future can I safely use SSR and fuse?
You could try replacing the voltage regulator on the Arduino, but it is very likely that other components have failed too. The first step would be to unsolder the voltage regulator, then see whether the Arduino works with USB power.
It would be useful to determine whether the relay caused the short. Can you remove the last relay from the board and then remove its cover?
Ok. I try that. But can you say how I have to do in the future. Can I use SSR and fuse?
I'd say first of all find out what actually caused the short (if any) . On pages 8-9 of your pdf, 2 traces are burnt. Clearly too much current went through them. What are these traces for ? what do they connect together ?
I think that knowing the cause will help to make a safe design.
I connected arduino to computer and after few seconds atmega2560 was really hot. Can it make a difference if i take crashed voltage regulator away?
eliasojala1234:
I connected arduino to computer and after few seconds atmega2560 was really hot. Can it make a difference if i take crashed voltage regulator away?
first thing to do is to change the regulator . It seems to be really sick and I wouldn't rely on it to regulate anything .
And taking it off will allow you to make sure there is no short (caused by excessive heat) on the board.
but I don't think it has anything to do with your 2560 getting hot if the arduino is connected by USB connector . I'm afraid something else (maybe the 2560 itself) is broken.
