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Old 11-06-2011, 11:29 PM   #11
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Originally Posted by samc View Post
Maybe a dumb observation but isn't 10g overkill for this switch? It can't handle the power that 10g does so why not downsize the wire to the switch?

Could be I just don't understand whats going on here.

I'm basing my control panel on this P-J schematic (minus the timer):




The load to the heating element will go thru the switch. P-J explains why the switch will work for this application here:

http://www.homebrewtalk.com/f170/controller-question-p-j-258594/#post3118433

Hope that helps
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Old 11-06-2011, 11:41 PM   #12
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15W will not cut it for 10ga..
Agreed. I used a 25W iron.
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Old 11-06-2011, 11:53 PM   #13
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Agreed. I used a 25W iron.
I picked up an adjustable 20 to 50 watt iron from Radio Shack, so I should be good. I got a little practice today soldering the 2 resistors from the schematic together, and then soldered them to a fuse holder. I did a lot of soldering of electronic stuff when I was a kid, but it's been a long time.
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Old 11-07-2011, 12:36 AM   #14
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Quote:
Originally Posted by samc View Post
Maybe a dumb observation but isn't 10g overkill for this switch? It can't handle the power that 10g does so why not downsize the wire to the switch?
+100 for the concern here. It looks to me like you are switching the heater elements through that switch, and I cannot believe it could possibly handle the current. Check that out carefully or you could create an overheat / fire condition.

DJG
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Old 11-07-2011, 12:46 AM   #15
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Originally Posted by laddg View Post
+100 for the concern here. It looks to me like you are switching the heater elements through that switch, and I cannot believe it could possibly handle the current. Check that out carefully or you could create an overheat / fire condition.

DJG
That's not my concern at all. All I was saying was that you don't have any need to size wire above the load the switch can handle, therefore the soldering issue is much easier. If a wire can handle 30 amps @ 240v but the switch only handles 10amps and you put 30 amps on it the switch will burn up.
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Old 11-07-2011, 01:51 AM   #16
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So the ? is still out, why do you need 10 gauge wire going into a switch that can't handle the load a 10 gauge can handle?

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Old 11-07-2011, 02:01 AM   #17
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A bit more food for thought - crimped connections are often recommended over solder in high current applications. A fault (even momentary) could melt the solder and cause further harm.

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Old 11-07-2011, 12:42 PM   #18
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Why are you bringing 10g wire to that switch? It can't handle the current that the wire can, so reducing to a smaller wire is prudent. If your system was assuming that high amperage will be routed through the switch, then you need to use a relay on this circuit so that the high amperage is not routed through the switch.

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Old 11-07-2011, 02:36 PM   #19
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I would not use this switch for high current. If the switch was meant to handle 30A, It would not be an issue connecting 10ga wire to it.

I also do not agree with the (2) 1k 1W resistors. They will not handle the power dissipated. I used (4) 1k 1W resistors in series. This gives 30mA fault current and dissipates 3.6W. It will trip the GFCI and cannot burn up if the GFCI fails to trip. The fuse in the circuit serves no function as the current is limited by the resistors. The fuse really does no harm but I think it is a weak link in a critical circuit.

**edit** And while I'm at it, why is anyone fusing the PID at 1A? I contacted an Auber tech and he said the PID is internally protected and no additional fusing is necessary. The PID could be connected after the 10A fuse in the above drawing and save a few components. And why a 10A fuse?? No wire size is indicated on the drawings. I used a 15A fuse with #14ga wire to power my receptacles and PID.

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Old 11-07-2011, 02:38 PM   #20
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How about using a terminal block rated for the 10 gauge wire, then run appropriate sized wire to your switches, PID, etc. from the block? Looks like you are wiring up a panel for an E-build, so this may be beneficial and keeps the inside of the control box looking clean.

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