UL listed combiner box options???

[Hungfish]

I am in need of a UL listed combiner box (4 in -12.9Amp--- 2 out-25.8Amp) . I found one at Watts247 and one at midnite.

1/ which one do guys use ? qualify, price ?

2/ would a DIY one using UL listed components (box, fuse holder, breaker...) meet code ? I read that some Solar-Boss here build some nice one.

thank you for your helps.

 

[Banjoman]

Either or depending on what you need. I have a Midnite one. DIY will not meet UL

 

[Lawrence_SoCal]

When SunPower did my install a couple of years ago, they used the inexpensive simple 8-space Eaton BR816L125P as a combiner box (inputs from 2 AC PV circuits (20A breakers each) and a 15A dual-pole breaker for the monitoring box.
sub-panel (combiner box) busbar lugs connected to 40A breaker in main load center

just mentioning in case something simple may suffice (AC in this case). If this request is about a DC combiner... then feel free to ignore this post ;^)

 

[cdsolar]

Either or depending on what you need. I have a Midnite one. DIY will not meet UL

Midnight's MNPV* boxes are just ETL listed boxes with ETL components that you choose, such as breakers.

I am happy with my two Midnite boxes, an MNPV6 at the ground mount array and an MNPV3 at the side of the barn that I use to hold a disconnect.

 

[SunDave]

If it were mine I would consider a UL listed IMO switch, and combine them before the switch with UL listed MC4 Y connectors. Opinions will vary. You would have to make sure ratings on everything match up with what you need amperage wise too.

In both of my arrays, I did not combine until the MPPT inputs. They had multiple inputs per MPPT.

 

[chrisski]

I see at least a couple of y connectors are UL CERTIFIED 6703, whatever that is?

I’d be reluctant to use a y connector on a house build, especially after sitting in the sun for 5 years.

combine them before the switch with UL listed MC4 Y connectors.

 

[sunsurfer]

UL listed vs certified. There is a big difference. Its all BS now a days.

 

[seneysolar]

100% use the Midnite box. Having 4 strings you will need the breakers anyways. Great product and easy for transition to conduit.

I imagine Y connectors on 4 strings would get you a failed inspection

 

[A-P]

Certainly buy an off-the-shelf UL listed combiner if there exists one that meets your needs. I spoke with my state’s building inspector about a similar project (creating a custom AC combiner box for Victron inverters). It is permissible to create a custom box using UL listed components (e.g., an appropriate UL listed enclosure containing DIN rails with finger-safe UL489 breakers and UL1953 power distribution blocks), so long you use them according to their UL listing and other code requirements are met. Happens all the time in industrial settings. Though as someone above alluded to, “UL listed” components are different from “UL recognized” (the latter of which can only be used within a UL listed product). If you go route #2, just keep this in mind.

EDIT: I spent a half hour trying to figure out what “UL certified” actually means… still not sure

 

[Hungfish]

My PoCo and city want "UL listed equipments". the Watt combiner box looks nice and complete if I can figure out how to make that a 4 in 4 out instead of 4 in 2 out... I should be good. Thankyou all for the suggestions.

 

[sunsurfer]

My PoCo and city want "UL listed equipments". the Watt combiner box looks nice and complete if I can figure out how to make that a 4 in 4 out instead of 4 in 2 out... I should be good. Thankyou all for the suggestions.

Just put a sticker on it from a cheap extension cord. Doubt they are smart enough to know.

 

[A-P]

Just put a sticker on it from a cheap extension cord. Doubt they are smart enough to know.

I’d be more concerned about home insurance over the inspector.

 

[cdsolar]

Certainly buy an off-the-shelf UL listed combiner if there exists one that meets your needs. I spoke with my state’s building inspector about a similar project (creating a custom AC combiner box for Victron inverters). It is permissible to create a custom box using UL listed components (e.g., an appropriate UL listed enclosure containing DIN rails with finger-safe UL489 breakers and UL1953 power distribution blocks), so long you use them according to their UL listing and other code requirements are met. Happens all the time in industrial settings. Though as someone above alluded to, “UL listed” components are different from “UL recognized” (the latter of which can only be used within a UL listed product). If you go route #2, just keep this in mind.

EDIT: I spent a half hour trying to figure out what “UL certified” actually means… still not sure

UL: Underwriters Laboratory

UL 'listed' is the proper term. As I understand it, UL 'certification' is the process by which a product becomes listed, and less precise writers will use the term UL 'certified'. Always ask to see the certificate - that term again -that the manufacturer gets when the product gets 'listed'. And look up the product yourself based on the information in the certificate.

But your question to a manufacturer should be: Is it UL (or NRTL) listed? And if the answer is yes, then, ask to what UL standard, and may I see the certificate and the file number? so you can look it up yourself.

UL 'Recognized' is a different beast and usually refers to a component that doesn't stand as a product by itself.

NRTL: or Nationally recognized testing lab, is a lab authorized to perform UL testing but not UL themselves. A product tested and listed by one of the NRTLs should not worry any AHJ, and is otherwise equivalent from a requirements perspective to UL doing the testing themselves.

Edit 2:

'Meets' or 'Conforms' to UL NNN or the like are marketing terms or the results of self testing and mean nothing to an AHJ.

Edit:

NRTL list: https://www.osha.gov/nationally-recognized-testing-laboratory-program/current-list-of-nrtls

 

[sunsurfer]

UL: Underwriters Laboratory

UL 'listed' is the proper term. As I understand it, UL 'certification' is the process by which a product becomes listed, and less precise writers will use the term UL 'certified'. Always ask to see the certificate - that term again -that the manufacturer gets when the product gets 'listed'. And look up the product yourself based on the information in the certificate.

Listed means it went through UL labs and they have it listed on their website. Certified means it was "tested" to their standard or what ever standard they claim. Anyone can make a certificate. NO ONE CHECKS. Audits are non-existant. Allot of the big names farm out to 3rd parties and there is NO lab data availble. ts all a joke.

Those that require said BS certs are even more of a joke. Its just a worthless sticker at this point. Fact.

 

[cdsolar]

UL lookup:
https://productiq.ulprospector.com/en/search