Greetings All, I too have tried all of the methods discussed so far in this thread. With regard to multi port tap block type connectors, I have used the Burndy Unitap product the most and have had good results. I like that they come with anti-oxide compound already in them and that the set screws have hex/allen socket heads. I may have had one or two of the set screws strip or come misaligned from the factory over the years, but have not found any major failures or arcing/burning. Overall I've had a good experience with the Burndy Unitap.
I have used the Ideal/Buchanan Splice Cap Crimp Connectors in some applications, but have not used them outdoors... I thought at one time I came across some literature for the nylon Splice Cap Insulators used on these which indicated there may be an environmental temperature rating related issue when considering them for PV install work. I'm looking for this spec now, but have not found it. All I find now regarding temperature is "Temperature Rating: 105° C (221°F)". Seems like using the Splice Cap Crimp Connectors with an appropriately rated quality heat shrink tubing product instead of the Splice Cap Insulator may also be a potential solution. I have used electrical rubber insulating tape, electrical silicone insulating tape, and electrical insulating mastic tapes to insulate and seal many various uninsulated connectors and etc too... Always with an application of quality electrical tape over them as well. USE-2/PV Wire with MC Connector connected to THWN-2 with MC Connector has worked well for me as well in a wire transition/junction box. The MC insulator boot sized for PV Wire may have been somewhat oversized for the THWN-2 conductor. It's always good to review the specs for the connector product and the specs for the wire to ensure all will be appropriately mated up in the field. I have used butt splice crimp connectors with integrated insulating shrink tubing such as the Molex Perma-Seal products. When used with the appropriate full cycle ratcheting crimping tool these make a very nice connection. Some of the butt splice connectors work well for transitioning from fine stranded wire to standard stranded THWN-2 conductors such as in the case of working with some of the micro inverter trunk cable systems etc. I always apply a second layer of quality heat shrink tubing over the connector and its integrated shrink. The use of these products and heat shrink tubing means bringing a cord and heat gun or torch to the array install area to seal the heat shrink. I prefer a heat gun for better control and a lesser likelihood of burning the connector, shrink, wire, or something or someone. Either way I can understand many folks may not want to be dealing with heat shrink products or having their install crews doing so, especially up on a pitched roof installation. Some of the Molex Perma-Seal butt splice products have a connector barrel made of tined copper and a 600V rating. Molex identifies some of these products for use in "consumer" and "industrial" applications. Some have CSA and UL "certification" on their respective spec sheets, but I have not researched the certifications by number to say for certain if use in a PV system wire transition box or junction box is a truly acceptable and compliant use for the product. Have any of you researched or worked with these Perma-Seal or similar products? I am interested to learn more and fully understand what their acceptable application are. Other companies such as 3M and Power Phase sell similar products, but often what I find are products intended for the automotive and marine industry. I absolutely do not want to be using or suggesting automotive and marine products for use in professional, code compliant residential and commercial electrical work. Link to Molex Perma-Seal Products: http://www.molex.com/molex/products/family?key=heat_sealable_terminals&channel=products&chanName=family&pageTitle=Introduction&parentKey=solderless_terminals&utm_source=ds&utm_medium=lit&utm_campaign=ipd Also; glad to see drain/weep holes mentioned too! Even if water is not getting in to the box/enclosure/body we want to make sure any condensation that develops can drain out. About 10-12 years ago I had a project with a large outdoor wireway/trough/gutter which would hold small amounts of water even though a number of drain/weep holes were drilled in its bottom side... A seasoned and friendly Electrical Inspector showed me how to make "wicks" out of single strands of wire... Coiled the single strand flat to lay on the bottom inside of the trough with a straight section of the single strand going through a weep hole to draw any water out. I put a few of these in the trough... It looked a bit funky but it seemed to help. Best regards, ----MATT Matthew Sirum P.O. Box 1227 Greenfield, MA 01302-1227 USA phone: +1.413.773.0611 email: [email protected] ------ Original Message Below ------ [RE-wrenches] Polaris gone bad? eric at harvesthesun.com eric at harvesthesun.com Thu Apr 6 10:35:58 PDT 2017 Wrenches, We have been having Polaris connectors start to fail on older installs. About 4 or 5 years ago we abandoned wire nuts in favor of the much more pricey, but deemed safer Polaris insulated tap connectors in our combiners. About a year ago we transitioned, about 80% away from Polaris to Buchannon connectors. We have had two recent call-backs on systems downed due to Polaris connectors burning up inside of boxes. (No damage beyond the connector itself). Recently we interfaced with another solar install firm that has gone back to wire nuts due to this same problem. Anyone else seeing this? Wondering if this is an industry-wide issue regarding a Polaris manufacturing defect or if we're still in the realm of isolated flukes. Eric SunHarvest (530) 559-5023 _______________________________________________ List sponsored by Redwood Alliance List Address: [email protected] Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/[email protected]/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
