Oops, great deal on the panels but pigtail leads are too short.

[trad]

Got great deal on 220W Sunpower panels from SanTan, but didn't realize that they came with short pigtail leads. As a result the pigtails are too short to go from panel to panel and connect in series. I was able to twist open the waterproof connection and pull the wire out of the diode box on the back of the panel much easier than I expected. It also seemed that I could push a wire back into this diode box and retighten the waterproof connection. I could create a 36 inch pigtail replacing the 10 inch pigtails already installed. Is this an acceptable way to fix short leads?

Or should I be buying or creating a bunch of 24 inch PV extension cables?

 

[Hedges]

I would expect wires to reach the next panel. Maybe not long enough for panels placed end to end (I rotate panels to fix that), or for skipping to every other panel.

Maybe these were made shorter and used with microinverters or RSD boxes.

Is your application one where RSD isn't required?

Off-brand connectors, mixing two brands at every connection and doubling the number of connections, increases failure and fire risk.

Some people say they cut off MC4, use crimp connectors and glue filled heat shrink. You could use that approach to extend the pigtails.

If you can properly connect longer pigtails in junction box, that is fine. Again, make both male and female same model MC4. Some junction boxes I've seen are push-fit with a particular crimp connector. Older ones were screw terminals.

 

[trad]

I would expect wires to reach the next panel. Maybe not long enough for panels placed end to end (I rotate panels to fix that), or for skipping to every other panel.

10 inch pigtails must have been for a micro inverter install. There is no way to reach the next panel.

Some people say they cut off MC4, use crimp connectors and glue filled heat shrink. You could use that approach to extend the pigtails.

This is interesting. Let me see if I can find what you are describing.

If you can properly connect longer pigtails in junction box, that is fine. Again, make both male and female same model MC4. Some junction boxes I've seen are push-fit with a particular crimp connector. Older ones were screw terminals.

These are sealed but maybe I can push longer 36 inch leads in place of these 10 inch ones.

 

[Hedges]

Is this a rooftop install where you would need RSD?
If so, like for microinverter, the short leads won't be a problem.

 

[scrubjaysnest]

For my portable set on the RV I popped the cover and unsoldered leads. Unscrewed the cord grips and ran 10 AWG through the cord grips tighted down and resoldered.

 

[DioRox]

Got great deal on 220W Sunpower panels from SanTan, but didn't realize that they came with short pigtail leads. As a result the pigtails are too short to go from panel to panel and connect in series. I was able to twist open the waterproof connection and pull the wire out of the diode box on the back of the panel much easier than I expected. It also seemed that I could push a wire back into this diode box and retighten the waterproof connection. I could create a 36 inch pigtail replacing the 10 inch pigtails already installed. Is this an acceptable way to fix short leads?

Or should I be buying or creating a bunch of 24 inch PV extension cables?

We just went to connect all of our 250w Sunpowers that are already all mounted that we got from SanTan and we have the same issue. Pretty shitty of them if you ask me. How could they not realize this?

 

[Recovering EE]

We just went to connect all of our 250w Sunpowers that are already all mounted that we got from SanTan and we have the same issue. Pretty shitty of them if you ask me. How could they not realize this?

They were likely anticipating that applications would include either per-panel micro-inverters or RSDs.

 

[DioRox]

They were likely anticipating that applications would include either per-panel micro-inverters or RSDs.

I thought the leads were coming out of micro-inverters? What are RSD's?

 

[Crowz]

I thought the leads were coming out of micro-inverters? What are RSD's?

Rapid Shutdown Device

 

[JoeHam]

We just went to connect all of our 250w Sunpowers that are already all mounted that we got from SanTan and we have the same issue. Pretty shitty of them if you ask me. How could they not realize this?

I don’t mean to be insensitive but…

How could you not realize this while mounting ?

When buying used equipment for DIY there is some personal responsibility IMHO.

I would make extension cables and get on to the next project

 

[efficientPV]

You can get a MC-4 crimper kit with a dozen pair of connectors for $30 with some wire. Only one needs to be replaced and made long for each panel. that would fix 24 panels.

 

[DioRox]

I don’t mean to be insensitive but…

How could you not realize this while mounting ?

When buying used equipment for DIY there is some personal responsibility IMHO.

I would make extension cables and get on to the next project

We aren't able to purchase these in person, they were shipped to us via freight, so purchased sight unseen. It would have been very appropriate for Santan to mention this to us during one of the calls. It wasn't a problem on the 8 other pallets of panels we purchased, so I wouldn't have had any reason to even think of asking. Once they got here, they are all coiled up, again, didn't even think to unravel one to check, because, it's pretty rare from what I gather. Obviously extension cables are what is going to be necessary to continue, but I'm not a fan of all of the extra connections.

 

[DioRox]

You can get a MC-4 crimper kit with a dozen pair of connectors for $30 with some wire. Only one needs to be replaced and made long for each panel. that would fix 24 panels.

Ya, I have wire and crimpers, just a pain in the ass after they are all mounted.

 

[Hedges]

Maybe end to end placement of panels (e.g. 2 x 6 array), only every other panel needs one cable extended.

Do they have MC4 already? How about splice in length of PV wire with two crimp + heat-shrink with hot melt. Those connections should be more reliable than the MC4 so doesn't bring down overall reliability.

I take it none of your installations require MLPE?

 

[DioRox]

Maybe end to end placement of panels (e.g. 2 x 6 array), only every other panel needs one cable extended.

Do they have MC4 already? How about splice in length of PV wire with two crimp + heat-shrink with hot melt. Those connections should be more reliable than the MC4 so doesn't bring down overall reliability.

I take it none of your installations require MLPE?

They are already mounted side by side and can't be moved. We made an eyebrow off of our shop for a covered walkway with them. Ya, I'm debating on splicing and heat shrinking in as you suggested. What is MLPE?

 

[Hedges]

Module Level Power Electronics,
e.g. microinverters, optimizers, RSD.

If going on dwelling roof, would get at least RSD so short cables would be a bug not a feature.
For ground mount I like cables long enough to skip a panel, may avoid need for any extensions.

Are you able to open junction boxes and connect new cables there? Old ones were screw terminal, then some funny plug-in ones. Many are glued or molded.

 

[DioRox]

Module Level Power Electronics,
e.g. microinverters, optimizers, RSD.

If going on dwelling roof, would get at least RSD so short cables would be a bug not a feature.
For ground mount I like cables long enough to skip a panel, may avoid need for any extensions.

Are you able to open junction boxes and connect new cables there? Old ones were screw terminal, then some funny plug-in ones. Many are glued or molded.

I'm sorry I'm not sure what you mean by, 'would get at least RSD so short cables would be a bug not a feature.'?

 

[Hedges]

If you have to mount RSD boxes like Tigo TS4-A-F because rapid-shutdown required for a new install on a dwelling, then the long wires from PV panel junction box to RSD box have to be clipped out of the way. Shorter would mean less wire. Probably doesn't help much, still have to coil it up and clip it somewhere.

If coiling wires, that makes an antenna for magnetic fields. If PV+ and PV- are laid side by side then coiled up together, that should cancel and reduce emission or pickup of EMI (and lightning, EMP, or CME surge). Which may or may not matter for a given installation. The PV cell configuration in panel itself has loop area too. One could probably make a more EMI friendly design if able to see electromagnetic fields.

 

[Recovering EE]

You can get a MC-4 crimper kit with a dozen pair of connectors for $30 with some wire. Only one needs to be replaced and made long for each panel. that would fix 24 panels.

I'd replace the MC4s on every panel, too, so all panel connections and extensions are from the same manufacturer.

I've found Bouge RV MC4s to be of decent quality.

 

[Zwy]

They are already mounted side by side and can't be moved. We made an eyebrow off of our shop for a covered walkway with them. Ya, I'm debating on splicing and heat shrinking in as you suggested. What is MLPE?

If panels are in series, what is the problem. 10 inches should reach the edge of the panel. You just need a long lead to one end at the start and end of the string.

 

[outsider]

Edit- whoops, wrong thread. Sorry about that.

 

[k490]

I'm just going cut them off use a butt connector and heat shrink tubing with adhesive melts into the connection. Those panels are stored outside at Santan in the rain. The condensation causes every panel to have water under it connector just lays in it open to water. I don't trust those connectors to last way too many stories here about MC-4 connectors melting from high voltage. I know there are good connectors out there have to also buy expensive crimping tools made by the same manufacture.