Higher amps

[jheil]

I'll need about 6 amps per channel for an upcoming project, and I was wondering if there's any reason not to replace the standard SSR4 triacs with a higher rating as long as I provide enough heat sinking and I double up the PCB traces with wire where necessary.  The other possibility I've considered is to double the number of triacs by running them in parallel.  I know that the load will never completely balance (I've seen that in paralleled mosfets), but even if it's 25% / 75%, it shouldn't exceed the rating.  If thermal runaway is a problem, maybe I could add some components to handle that.

[rrowan]

I don't think its a good idea to exceed the specs that RJ has set for the ssr4 or any of his hardware

could be dangerous but I'll let RJ say why

Rick R.

P.S.
If you don't need those channels to dim. This is what I used last year, a couple of channels on a MR-16 set to on or off with the section of lights controlled by a cydom 10amp relay (ie: hockey puck)

[n1ist]

Couldn't you use a random (non-zero cross) hockey puck instead of the opto and triac?  That will get the high current off the board.
/mike

[RJ]

I'll need about 6 amps per channel for an upcoming project, and I was wondering if there's any reason not to replace the standard SSR4 triacs with a higher rating as long as I provide enough heat sinking and I double up the PCB traces with wire where necessary.  The other possibility I've considered is to double the number of triacs by running them in parallel.  I know that the load will never completely balance (I've seen that in paralleled mosfets), but even if it's 25% / 75%, it shouldn't exceed the rating.  If thermal runaway is a problem, maybe I could add some components to handle that.

"and I was wondering if there's any reason"   

Yes there are a whole lot of reasons why you can not and should not do this. First it is a fire hazard. There is not room to get rid of that much heat in the SSR4 even if you had a heatsink that could. You would be putting the equivilent of a 40 watt light bulb in that case. It will get too hot.

There are a whole lot of other reasons this is a bad idea and not safe. Can I suggest that instead of spending all that money to make something I would worry would burn your house down you simply use this instead :

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Notice that even as large as it is it is limited to its dissipation but it does get you almost where you need to be.  They also are limited because while you want to control 24 amps the standard circuits can only deliver 15 amps so how are you going to feed that much current to a ssr4. Then there is the connectors on the board that are not rated for anywhere near those current levels.

The SSR4 is limited to 1 amp per channel without a heatsink and 2 amps with it for good reasons. This is not a triac issue but heat dissipation/traces/connector rating/safety issue.  6 amps a channel is not running a little over safe it would be way outside the safe range on this controller.   

Use a couple of them and split your lights up, or use a commercial controller.  I can' t afford to have people getting hurt with my stuff it would take all the fun out of it for me.

RJ

[n1ist]

Careful with those shoebox dimmers - they claim 600w/channel, but also have a max of 15A total, and in reality a lot of them use 10A IEC connectors and 6A switches...
/mike

[sirwesley]

I have a few of those "shoebox" controllers.  Can anyone suggest a good way to weatherproof them?  Are there any cases out there for those? 

[crazybob]

I've been using those controllers for years until I found this site. I put them in a rubbermade container with holes drilled on the underside for cords to go in and out. The lip of the lid overhangs to make sure no water can get in from the top. The holes on bottom are about 1.5 inch to accomodate all cords, and i put the whole thing up on a couple bricks to keep it directly off the round.

[crazybob]

Speaking of higher amps... I'm looking to use some floodlights on the SSR4's that I am ordering in the coop. In figuring how many volts each channel could handle, I divide watts / volts = amps, right? So, in order to stay under 1 amp, I could use up to a 120 watt light?
Just wanted to make sure my math and understanding of this was correct. Also, Can the SSR4 handle having one amp turned on for 15-20 minutes at a time? Or is it made mostly just for on/off?

[RJ]

Your math is correct 1 amp at 120 volts = 120 watts. You can turn the 1 amp on continuosly in the ssr4.

RJ

[crazybob]

Thanks! I do believe I may FINALLY be getting the hang of this!