The MC4 connector on both my Canadian and JA Solar panels are good quality, tho not the same. Wiring up the strings we had to buy whatever brads were in stock locally. Most of them were unbranded, as stock was very limited, we got 3 different types. Wee needed 16 connections in total. 6 of the connectors was Onesto brand. I had to replace all of them, pure garbage. I managed to find Staubli connector in Bloemfontein and ordered them online. The difference is day and night!

Dont bother with Onesto…. Save yourself the headache and money by not buying connectors twice.
 

Edited September 19, 20214 yr by Sarel
Typos

Thanks for the heads up. Was the connection intermittent or high resistance in the bad connectors?

Basically it made no contact at all, and no it was crimped with the correct tool from Staubli. Both the plastic and the pins are really badly made and as a result the pin does not seat properly inside the connector. both the male and female pins sizings are incorrect as well. What happens when you try and insert the connector in the opposite one, the pin gets pushed back by the other connector and you cannot see that. This means no electrical connection at all in my case. My installer had this happen a number of times already, but due to the shortage of stock, we had to grab what we needed.

Thanks for the info, I'll stay away from the bad one's. I normally get my stuff from Midlands Solar in Pietermaritzburg, and so far am happy, with no problems.

Its a small shop, but he seems to be able to source most things, if he has none in stock.

These MC4's don't have a brand name, but I've had no issues at all. 👍