Installing Panels Query's

Ako

I have just had some 460 Watt 50 volt Panels installed and noticed a couple of the connectors the installer had fitted to cables he made were  not even hand tight , they were louse which made me wonder if he did everything else correctly .

The other thing i am uncertain about is that the leads from the panels would have the same MC4 connectors on each end , a positive male from the panel would be connected to a female on the cable then he fitted another Female on the other end of the cable , the same with the Negative , he used the same terminals each end between the panels and the underground cable to the house which also requited an MC4 so he then had to fit the opposite to .

I noticed the cables that came attached to the different panels were left as they were delivered , coiled and zip tied and wondered if this would be a problem with the wires heating up as i did read that tight bends are to be avoided for this reason .

Possibly i am being over critical and worrying about nothing but any guidance would be very much appreciated .

littleharbor2

If the extension cables have the same MC-4s on either end then He has reversed the polarity. Is your system up and running? An extension cable should end with the same connector that he plugged into on the panel.
 As to the coiled wires. you are being over critical. That part of the install looks fine.

BB.

In general, it is not the "tight bends" that need to be avoided, it is the coiling of cables... Each cable generates a bit of heat (resistance heating) and when you have 5-10-etc. loops tied together, their heat adds together and can overheat the entire coil.

Usually this is a bigger issue when you have a 100 foot extension cord and most of it in a coil running rated current through it (such as 15 amps through a 14 AWG cord). Your panels probably have 12 or 10 AWG cables and are running less than 10 amps--So heating of the "coil/roll" of cable is probably not a a big issue here, especially with the relatively few "wraps" of cable.

A couple of other suggestions... One is that the "union" of the two cables in your first photo--I would suggest that you move the connections to the right or left so that rain from between the two panels does not land on the connections can cause possible corrosion. Also, I would suggest that the connection be at the "top of the loop" so that water runs down hill--Not at the bottom where water runs to the connections (avoid corrosion). Yes the MC4 connectors are supposed to be water proof--But it does not hurt to keep water away with "drip loops" so that water cannot follow the cable to connections).

It does not matter for "small diameter loops" like these... But if you are in an area with lightning and/or want an electrically "quieter" solar system (HAM radio, etc.)... Circular loops do act like "better" antennas to receive and broadcast radio frequencies. Better to keep +/- (and AC wiring) running in parallel so to make for "poor antennas". And if you have extra cabling, wrap in figure 8's--Again to make for poor RF properties.

The "drip loops" are something I always try to do... The keeping +/- and Hot/Return for AC cables close together (bundle tied, in the "same conduit" etc. is also a very good ideal. The figure 8 for extra cable "loops" is helpful, but maybe a bit "over the top" as a requirement for smaller sized loops and no RF/Lightning issues).

-Bill