Flexible Panels, Mounting Methods and Heat

[Barboots]

Help please.

Having had Terry point out that I had assessed the purpose of the panel's diode incorrectly, I need to find something ex stock in Perth urgently. Obviously there are better devices out there, but it must be on the shelf here. So I'm after opinions on these for blocking purposes:

http://www.altronics.com.au/p/z0065-stp ... tky-diode/

Datasheet: http://cloud.tapatalk.com/s/5a39b4dad93 ... asheet.pdf

If they are unsuitable, alternatives welcome.

Cheers, Steve

[T1 Terry]

Why don't you reuse the diodes out of the failed panels? Just wire them in the positive cable at the MC4 connector, you could cut the plugs off the stuffed panel and put the diode in between so the panel positive plugs into the non strip end of the diode and the cable heading to the solar regulator goes into the striped end of the diode.

T1 Terry

[Barboots]

I guess I could have Terry, though it took a bit of hacking to extract it from the silicon filled junction box. I also got the impression that they were unsuitable, so didn't look as hard as I might have. Overall I've been finding the spec sheets hard work, especially the effect of temperature on the forward voltage, and therefore lost power. Some of the enticing specs go out the window when practical environments are applied.

I ended up buying the ones detailed a post above. As they are TO-220 devices, I also bought a small heatsink for them. Hopefully I don't cop too much of a performance hit from them whilst in full sun.

Thanks again for your guidance.

Cheers, Steve

[dapope]

I guess I could have Terry, though it took a bit of hacking to extract it from the silicon filled junction box. I also got the impression that they were unsuitable, so didn't look as hard as I might have. Overall I've been finding the spec sheets hard work, especially the effect of temperature on the forward voltage, and therefore lost power. Some of the enticing specs go out the window when practical environments are applied.

I ended up buying the ones detailed a post above. As they are TO-220 devices, I also bought a small heatsink for them. Hopefully I don't cop too much of a performance hit from them whilst in full sun.

Thanks again for your guidance.

Cheers, Steve

When you have the diodes done, can you take a photo for numnuts like me so I can see what you have done?
Cheers,

[Barboots]

The junction box I fitted for the previous installation is getting really tight with the addition of diodes. I've made a few compromises... but a few dabs of RTV silicon should serve to ruggedise this assembly.

[Barboots]

The fixings:

[dapope]

Cheers for that

[T1 Terry]

When I get a few mins spare I'll put up a photo of how we are doing the diode thing. Less bulky and suits how we connect the panels to the extension cabling as we knock the connector pin out of the plastic plug, push the pins all the way home and solder the joint, then cover with heat shrink. This allows us to run the cables under the or even through the Lexan rather than trying to get the plugs to fit through conduit. The other problem with using the MC4 plugs as provided is the poor contact area between the pin and socket. If you look at an MC4 connector that has been in service for as little as 12 mths you will see the tip of the pin and first stage of the socket badly pitted due to a poor contact and arcing across the connection.

T1 Terry

[Eddy]

Hi Terry

If you look at an MC4 connector that has been in service for as little as 12 mths you will see the tip of the pin and first stage of the socket badly pitted due to a poor contact and arcing across the connection.

What connector/method have you found best to use instead of the mc4 connector

Thanks

Eddy

[T1 Terry]

Hi Terry

If you look at an MC4 connector that has been in service for as little as 12 mths you will see the tip of the pin and first stage of the socket badly pitted due to a poor contact and arcing across the connection.

What connector/method have you found best to use instead of the mc4 connector

Thanks

Eddy

We still use the MC4 pins and sockets, just discard the black plastic outside bit. A suitable metal rod punched down through the plug after undoing the gland nut on the cable end will get the pin/socket out of the plug, a screw driver or thumb nail will remove the spring steel retaining clip if it comes out with the pin/socket, then slid the rubber seal and cap off the cable. Measure a suitable length of heat shrink and cut it from the roll and slide this over the cable. Fit a the mating pin/socket to the 6mm auto cable or what ever you wish to use to extend the cable and then plug the 2 together. With a hot air gun ( yes I'm serious) heat the joint for roughly 20 secs and them touch the resin core solder to the joint stroking it along each side and you will see the solder start to fuse into the metal and disappear into the joint. Remove the heat and wait a bit until you can hold the joint in your hand without flinching, then try to pull it apart so you know if you did a good job, if you had a winner split the heat shrink over the joint and shrink it with the hot air gun, job done and move on to the next joint.
The peace of mind knowing the cabling from panel to junction box is as good as it can get makes diagnosing problems so much easier, you have no idea how many hrs I've wasted searching for problems that finally lead back to poor MC4 connections that had been ok for the lest 12 mths or more. Even better is difference in charging amps once you solder all the connectors and get rid of all those poor connector losses.

T1 Terry