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AC plug for DC purpose?

Madsalts

Sep 25, 2014
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I have a trolling motor to which I'm hooking up a Pulse Width Modulator. I have installed plugs meant for DC purposes, but am not happy with them. These plugs use a solder connection to wire, which has failed twice already. I'd rather screw a wire down than solder it. Furthermore, the plugs are a real pain to separate. The system has a voltage of 12V and a max draw of 29A. I'd like to set the system up with AC jacks and plugs, since these will not have the aforementioned problems. I see that most AC plugs are rated for 15A and 125V. My purpose would use less power overall and less voltage, but would still send significantly more amperage through the plug. Is this a problem, or can I use AC jacks/plugs? Thanks.
 

Minder

Apr 24, 2015
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You can get a larger version that is 50amps.
If in NA you can get them at HD or any electrical supplier.
If the 30amp draw is just for a brief period, you May get away with it with the 15a. but it may be a problem with terminating that size of wire.
M.
 

AnalogKid

Jun 10, 2015
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Generally speaking, connector contact spacing, the air gap between metal parts, sets the max. operating voltage; metal thickness sets the max. current rating. So a connector that is rated for 15 A at 1000 V is good for only 15 A at 1 V. The limiting factor is heat generated by the resistance at the actual contact area, which can be way smaller than the overall size of a connector pin. You might be able to get away with taking a connector rated for continuous duty at one current and running it a higher current for a shorter time, but there is no way to calculate what the final reliability might be.

ak
 

Alec_t

Jul 7, 2015
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These plugs use a solder connection to wire, which has failed twice already.
What was the failure mode? If solder joint melted then the connector is overloaded. If wire fractured then proper cable support (e.g. a rigid splint) at and near the joint is needed.
 

Madsalts

Sep 25, 2014
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The connectors I am using (made for DC) attach to wire via solder. The wire pulled out of the solder. This might be solved to some degree by separating the strands of wire from each other prior to soldering. If I were to support the wire, I'd have to jerry rig something. The plug in the previous post is similar to what I'm already using.
 

AnalogKid

Jun 10, 2015
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Those look like knock-offs of Andereson Power connectors, the gold standard of golf cart chargers. The contacts are supposed to be crimped onto the wire, not soldered. Pull=out probably is caused by not enough heat and/or flux during soldering. If might be counter-intuitive, but crimping is more reliable.

I've seen the connectors and crimp tools at Lowes / Home Depot.

ak
 

Tha fios agaibh

Aug 11, 2014
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Not relevant to your boat, but there's an electrical code that says to make mechanical connections (crimp) before any soldering. This is to prevent solder blowout like you experienced.

Not bad advice in your situation.
It's also important to use the right crimp tool for the job.
 

Externet

Aug 24, 2009
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Yes. AC plugs/jacks for DC.
If you choose a 4 terminal type, can wire two and two paralleled for redundant current sharing. No way to plug it reversed polarity either. And meant to carry the amperage.
----> https://duckduckgo.com/?q=range+plug+and+outlet&t=canonical&ia=images

----> http://electrical.about.com/od/appliances/ss/rangereceptacle.htm#step5

Or the less known and less brute Neutrik NL4, NL8 speakeon :

----> https://duckduckgo.com/?q=speakon+connectors&t=canonical&ia=images
----> http://www.neutrik.com/en/?q=nl4
 
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