MC4 Connectors for 8 AWG Wire Connecting to MC4 for 10 AWG Wire

[Santa]

Kit includes hex die labeled 0, 2, 4, 6, 7, 8, 10, 12, 14 AWG.
But really terminal size (including wall thickness) is what the die has to fit.
Perhaps one will do the job for you. HF has a return policy, and if there's a store local to you, you could open the package and see how a connector fits.

https://shop.harborfreight.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/6/6/66150_W3.jpg

EDITED BY ME: Is that for MC4 connectors?? It looks like it's for lug terminals...

 

[Hedges]

4. Also, will it be a problem using the 10 AWG Y-branch connectors with the 8 AWG wire? In other words, will I need to find a y-branch connector that is 8 AWG?

A 10 AWG Y-branch would have 10 AWG carrying the current from two strings. That is OK without fuses if ampacity of 10 AWG is sufficiently greater than the combined Isc of the two strings. If that doesn't have sufficient margin then an MC4 fuse could be used. None of my panels generate high enough current for that to be a problem. Only if a fuse greater than 30A was needed to carry current from two strings would an 8 AWG rather than 10 AWG "Y" be needed.

After the "Y" you could use 8 AWG for reduced resistance in a long run.

When I first built my system I didn't use any "Y" and I didn't crimp any MC connectors. I bought pre-crimped MC3 cables. (earlier generation of PV, MC3 not MC4). I cut the cables in half and put them through glands into junction boxes. In some cases I joined two, 10 AWG MC cables to one 8 AWG THHN wire which ran through conduit to the disconnect. My recent addition I did something similar with MC4 (newer panels) but ran a single 12 AWG THHN per PV string because more than two strings joined at fuses in the combiner.

Oh, correction on my earlier comment! It wasn't MC4 I crimped but rather MC3, repairing some used panels I bought. The MC3 just had a round barrel. Looks like MC4 have a strain-relief crimp on the insulation like Molex connectors. So that Harbor Freight crimper may not work for MC4 like it did for MC3:

MC4 Solar Panels Connectors

IP65 solar panels MC4 connectors,PV MC4 Solar connector contains 1 male and 1 female MC4 solar panel connector. MC4 Solar Connector are used to connector solar cable that are exposed to the weather. These are industry standard solar connector.

www.nbgaia.com

 

[Santa]

I think I may have found a crimper for mc4's and 8awg wire??: https://www.amazon.com/dp/B00N3PTXJS?tag=rvtitostore-20

 

[Santa]

Actually that tool won't work. I need it for 8AWG wire which is equivalent to 10 mm squared. Still looking for a proper crimper.

 

[Hedges]

I think I may have found a crimper for mc4's and 8awg wire??: https://www.amazon.com/dp/B00N3PTXJS?tag=rvtitostore-20

It says, " AWG:26-10AWG"
Also, doesn't look like it crimps the strain-relief portion for you. The die has only a single profile, not one for the wire and another for the insulation.

Not specifically MC, but here are a couple crimpers that claim 8 AWG and appear to be for un-insulated terminals. You might have to deal with the strain-relief crimp separately using pliers. This doesn't give you a UL listed crimper/terminal combo or anything like that, but ...

Sta-Kon TBM45S 10.46" Ratchet Crimper for sale online | eBay

Find many great new & used options and get the best deals for Sta-Kon TBM45S 10.46" Ratchet Crimper at the best online prices at eBay! Free shipping for many products!

www.ebay.com

Steel Dragon Tools Mechanical Crimper for 8awg- 250mcm With Rotating Dies for sale online | eBay

Find many great new & used options and get the best deals for Steel Dragon Tools Mechanical Crimper for 8awg- 250mcm With Rotating Dies at the best online prices at eBay! Free shipping for many products!

www.ebay.com

Looks like one produces a square shape, the other a hex.

Then there is also soldering, which has its issues but is probably OK.

 

[Santa]

It says, " AWG:26-10AWG"
Also, doesn't look like it crimps the strain-relief portion for you. The die has only a single profile, not one for the wire and another for the insulation.

Not specifically MC, but here are a couple crimpers that claim 8 AWG and appear to be for un-insulated terminals. You might have to deal with the strain-relief crimp separately using pliers. This doesn't give you a UL listed crimper/terminal combo or anything like that, but ...

Sta-Kon TBM45S 10.46" Ratchet Crimper for sale online | eBay

Find many great new & used options and get the best deals for Sta-Kon TBM45S 10.46" Ratchet Crimper at the best online prices at eBay! Free shipping for many products!

www.ebay.com

Steel Dragon Tools Mechanical Crimper for 8awg- 250mcm With Rotating Dies for sale online | eBay

Find many great new & used options and get the best deals for Steel Dragon Tools Mechanical Crimper for 8awg- 250mcm With Rotating Dies at the best online prices at eBay! Free shipping for many products!

www.ebay.com

Looks like one produces a square shape, the other a hex.

Then there is also soldering, which has its issues but is probably OK.

BUT ARE THESE FOR MC4 CONNECTORS?? I AM NOT DOING LUG CONNECTORS.

 

[Hedges]

BUT ARE THESE FOR MC4 CONNECTORS?? I AM NOT DOING LUG CONNECTORS.

Nope.

Here's one that is. MC4 and 8/10/12 AWG. $500. Doesn't fit your stated goal of "cheap. Not over $300"

Staubli Multi-Contact PV-CZM, MC4 Crimping Pliers

Click here for Staubli Multi-Contact Multi-Contact PV-CZM, MC4 Crimping Pliers from altE® - Making Renewable Do-able since 1999.

www.altestore.com

This may be the same thing used for about $300:

Original Stabuli Crimping Tool PV-CZM-22100 MC crimper | eBay

Original Stabuli Crimping Tool PV-CZM-22100 MC crimper. Condition is Manufacturer refurbished. Shipped with USPS Priority Mail.

www.ebay.com

New about $400:

Multi Contact Crimpzange Typ Pv-czm-16100a Mc4 for sale online | eBay

Find many great new & used options and get the best deals for Multi Contact Crimpzange Typ Pv-czm-16100a Mc4 at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

[Santa]

I found one for $319 with 7% off

 

[Deleted member 165]

Well I don't know, but it sure is good to see you Santa. I'm feeling all nostalgic. ☺

 

[joshuaaa]

As far as connectors, I am also looking for 8awg compatible connectors

These do not specify the awg, but they do say 50amps, so I assume that they are 8 awg.

Comes with 1 pair of 4 branch connectors plus 5 pairs of normal mc4s.

Amazon.com

 

[Pixie RN]

I found one for $319 with 7% off

What did you end up using to crimp your 8 awg MC4 connections? I’m in the exact same boat. I have all my connectors, wire, etc, just need a MC4 crimper for 8 AWG without breaking the bank.

 

[iceledoar]

I bought cables with connectors on them. When I expand the solar array I will install a combiner box and do away with the MC’s except at the panels.