Should controller pv and batt inputs be fully sealed up?

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Re: Should controller pv and batt inputs be fully sealed up?

Postby jules » Tue Dec 11, 2018 7:44 am

If you're not happy to go with the simple but effective option of bare wire fitted directly into the screw terminal then perhaps you could go with davidg's suggestion "2" from a few posts back and use conductive paste without ferrules. [Conductive paste has to be used sparingly as it has the potential to spread to places you don't want it and thus cause electrical leaks].

If you're using ferrules, a high quality [read expensive] crimper is necessary to do a good job on the ferrules and you might be going backwards rather than forwards here. A ferrule on its own isn't going to prevent access of air and slow oxidation of exposed copper though it does add another couple of resistance boundaries through which power has to travel.
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Re: Should controller pv and batt inputs be fully sealed up?

Postby australsolarier » Tue Dec 11, 2018 1:01 pm

jules,
most civilized countries have regulations that ferrules have to be used.
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Re: Should controller pv and batt inputs be fully sealed up?

Postby jules » Tue Dec 11, 2018 1:59 pm

davidg wrote:if you really want to seal against corrosion, the best and really only way/s are

1. use crimped ferules with electrical conductive paste (copper version for copper)
2. electrical conductive paste without ferrules

The fact is copper will go dull quite quickly however the conduction of properly tightened copper connections should not cause any issues normally.

If you are in the tropics then use a conductive grease, silicone and the like will NOT stop moisture.


I'm certainly not well read when it comes to the details of our regulations but the original suggestion came from davidg who in my experience, always insists on high standards.

In what situations do our regs. require ferrules to be used australsolier?
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Re: Should controller pv and batt inputs be fully sealed up?

Postby australsolarier » Tue Dec 11, 2018 5:25 pm

jules,
i know they use them in europe. (even ukraine, moldava)
i don't know about australia. however they use ferrules in high current connections like in the steel works. also i do not remember screw terminals in europe except for hobbyists. junction boxes always had those two flat compression plates. (like in breakers)

when you look at a wall socket that has been thirty years on the wall, the copper is not corroded. maybe a dull sheen. again the exposed areas of the copper don't matter. it is the contact that is important. so unless the junction is exposed to the weather or chemicals or fumes, etc. it should not be a problem.
the ferrules do not have high resistance. they are made out of copper with nickel plating or something. the ferrule is also not used to stop corrosion. it is being made to make better contact. and they are particularly helpful in screw terminals. it makes for a tidier installation overall.
it will eventually come to australian regulation.
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Re: Should controller pv and batt inputs be fully sealed up?

Postby davidg » Tue Dec 11, 2018 6:09 pm

australsolarier wrote:it is being made to make better contact. and they are particularly helpful in screw terminals. it makes for a tidier installation overall.
it will eventually come to australian regulation.


I'm not sure it will, anytime soon the latest AS3000:2018 makes no mention of them.

They don't provide a single improvement to clamp style connections in say CB's, RCD's or RCBO's in fact they would likely make it a poorer connection. In a GPO (powerpoint) they typically will not improve anything for single multi stand 2.5mm2 cable inserted into a double GPO connection it is normal to twist the strands together and then fold them through 180degrees to ensure there is plenty of copper to contact with the screw, for 2 wires typically twisted together, a GPO will generally take 3 x 2.5m2 cables in a connection that's about its limit, if you are really careful you can get away with 4. If the wires are not twisted together then the connection to the other wires will not be anywhere near as good, an important reason for twisting them together correctly in the first place.
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Re: Should controller pv and batt inputs be fully sealed up?

Postby Jman » Tue Dec 11, 2018 10:07 pm

davidg wrote:13mm2 where does that come from ?


Just took another look at my wire & its actually 14mm2. And I was using 16mm2 ferrules so yeah I made a mistake. Next time I will use 16mm2 wire.

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Re: Should controller pv and batt inputs be fully sealed up?

Postby australsolarier » Wed Dec 12, 2018 5:27 am

jman,
how do you figure out the size of the wires? do you measure them?
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Re: Should controller pv and batt inputs be fully sealed up?

Postby Jman » Thu Dec 13, 2018 12:09 am

australsolarier wrote:jman,
how do you figure out the size of the wires? do you measure them?


No its just printed on the outside twin sheath.

But, I tried again crimping with much more hand force & I could not pull off even with a pair of pliers, so the size mismatch looks to not be much of an issue & the cheapo crimpers perhaps? However after a few hard pulls they do come off, to me this is to be expected as the square shape crimp just doesn't look to produce a strong join like ring terminal lugs with indent crimpers etc.
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Re: Should controller pv and batt inputs be fully sealed up?

Postby australsolarier » Thu Dec 13, 2018 5:45 am

yes if you as much they do come off
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