Maximum amps per channel

[UncleBuck]

The manual states 4 amps per channel maximum. Is there any leeway on the 4 amp max load? I currently have 4 strands of c7 lights totalling 4.12 amps on a single channel. Is that to much of a load?? I would like to turn them on 1 hour before and after the show but when I have all the channels on constant using the test mode the heat sink gets very hot to the point that you can't touch it. How hot is the heat sink generally get?

I will only have 3 channels on constant before and after the show for one hour and the remaining 13 channels will off.

You can tell this is my first year!! 

[UncleBuck]

Sorry the lights are incandescent.

[Jeffl]

The triacs in the mouser BOM are rated for 6.  It's probably a matter of what RJ says you should and what the triac is capable of.  You made me think but I'm not pushing anything this hard.  I think I'm only doing a max of 3.

[pk]

Last year I had a string of C9s that were 4.2 amps when full on.  I used them on an express and they were fine.  I only had 1 string using that much current. 

Have you considered dimming the lights to reduce the current a bit?

[rrowan]

Its less about the triac and more about the pcb traces handling the current

Rick R.

[UncleBuck]

Excellent idea PK. Can I assume then if I dim to 50% ON that is 1/2 the amp load? So if my 4 strings are 4.12 full on then they would be 2.06 dimmed at 50%.

[ratroder]

How about spreading the 4 channels about the board. Like channels 1,5,9,13 for the c9s to spread the heat out on the heat sink.

[chrisatpsu]

limit those channels to only going as high as 243 (instead of 256) for your full on. or 95% to keep them at or under 4A

[pk]

UncleBuck - correct.  The heatsink should be cooler too!! 

[DanHouston]

The documentation says:
Using both power inputs (ie: two cords on two separate circuits (ie: breakers))
40 amps Total for the Express with approved heat sink attached
4 amps per channel maximum with approved heat sink attached

Using one power input (see below - Appendix A single power input mod)
20 amps Total for the Express with approved heat sink attached
4 amps per channel maximum with approved heat sink attached

So while most things have room to wiggle I'm not sure I'd risk the fire. Spreading it around to other channels or if you trust yourself to keep it dim.

[barbotte]

in vixen set them up to 80 % instead of 100 and no one will notice any difference except the board lol
cheer

[tbone321]

The board will handle the 4.2A without risk of fire.  RJ makes sure to put some safety margin in his specs and it really is a good idea to follow them.  If your a little over like this you should be ok but remember that some of these light sets tend to leak some current when they get wet which could move you even closer to the limits of the triac.

[pk]

UncleBuck - Be sure to observe the maximum current of 20 amps for each power input.  You can not run all 8 channels associated with one power input at the maximum rating of 4 amps without exceeding the 20 amp limit.  (I think 4 amps x 8 is still 32amps LOL) 

[tbone321]

Unless he has some unconventional wiring at his house, exceeding 20A is going to blow the breaker that the outlet he is using is wired to. 

[chrisatpsu]

I currently have 4 strands of c7 lights totalling 4.12 amps on a single channel.