[RE-wrenches] MC4s are listed for THWN, right?

[Ray]

I have been busted by inspectors for "modifying a UL device in a way 
that is not permitted in its listing", or something like that.  While 
weep holes make all the sense in the world, and I have commonly seen 
1/4" holes drilled in LBs for ground wires, etc; one out of ten AHJs 
might not like it.

Ray Walters
Remote Solar
303 505-8760

On 4/29/21 9:43 AM, frenergy wrote:
> Eric,
>
>             I like your idea of drilling the weepage holes as long as 
> they are not big enough to allow critters like wasps to make a home 
> inside the J-box.  We will use aluminum tape on unused mounting holes 
> in the back of the box for the same reason. Lurkers welcome.
>
> Bill
>
> Feather River Solar Electric
> Bill Battagin, Owner
> 4291 Nelson St.
> Taylorsville, CA 95983
> 530.284.7849
> CA Lic 874049
> www.frenergy.net
>
> On 4/28/2021 6:19 PM, ericstev at vermontel.net wrote:
>>
>> Wrenches,
>>
>> I am normally a lurker on the List, but I would like to add a fact 
>> observation and a personal preference to the topics raised by this 
>> discussion.
>>
>> First, THWN does have PVC as its primary insulation, but it is 
>> sheathed in Nylon which is a polyamide plastic.  Therefore the 
>> compatibility with MC4 connectors should be polyamide being squeezed 
>> by the restraining bushing in the MC4, not PVC.
>>
>> I prefer Buchanan copper crimp connectors when splicing PV wire to 
>> THWN-2 in a roof junction box.  The bared wires should be lightly 
>> doped with NO-OX-ID A-Special grease 
>> https://www.sanchem.com/electrical-contact-lubricant.html 
>> <https://www.sanchem.com/electrical-contact-lubricant.html> before 
>> sleeving and crimping with the crimp sleeve to repel entry of 
>> moisture and corrosive gasses into the wire joint.  I consider the 
>> crimped joint to be superior to any screw-clamped joint that would be 
>> made in a Polaris style connector.  I also drill weepage holes in the 
>> bottom corner of the junction box to mitigate any collection of water.
>>
>> Eric Stevens, Vermont Made Energy
>>
>>
>