My Zivan NG1 in my 2002 had problems a few years ago with over heating of the input 120VAC pigtail( spade lugs ) which resulted in a melted fuse holder. I had fixed that with new lugs, new spade connectors and a new fuse holder. Later my cooling fan failed and that caused some internal overheating and charger failure. I just picked up another Zivan NG1 and before putting it in I noticed some rattling in the case so I took it off and it was just the 2 circuit board mounting spacers at the heatsinks. Looking around I noticed the input 120VAC spade lugs and wires were darkened from heating and after doing a top-off charge to check the charger I felt the black input Line wire was warm.
Has anyone else seen this on the Zivan and done anything to remedy it?
When I took my NG1 in to the distributor in Sac to get it “tuned” and get an extra chip with different profiles, he punched a bunch of holes in the plastic cover around the cord/plug area. Said the heat build up was known about.
While you have it apart, check the interlock pads where the terminals slip on. Carefully scrape away any extra varnish. Overspray was another issue with these. Hit a bump, the terminal moves a smidge, ends up on varnish, controller mistakes this for the interlock and thinks you just plugged the cart in so it shuts off instantly… 10 shades of “ohhhhh shyyyyttt” if you are at speed in traffic…
I did that a couple of hours ago on the 120VAC input terminals and there was conformal coating covering most of the entire terminal. Interlock terminals looked pretty good but still had a little bit of conformal coating on the lower half of each split terminal.
The added airflow holes are a great idea. As I’d mentioned, the original charger got so hot at the input wires it melted things. I had my lithium batteries at that point so it was pushing more total charge time than the old Pb batteries. And no doubt some of it was conformal coating and no airflow. Thanks for the tips.
the fan is fine and pulls lots of air through it. The problem is the ran is on the top right side of the charger and all the heat sinks and power circuit is along that right side of the charger along with some vents on the bottom only on the right side. There are no air inlet vents along the right side or bottom right side of the cover so lots of stagnant air and heat buildup. Input terminals seem to be undersized for the current and those spade/blade type terminals are not great for high power situations.
Ok, then a bit of airflow study and redesign may help.
Spitballing inserted here (thinking out loud).
Also, check your input V when under max load. Check right at the board if you are real careful. A bad connection at the spades, or any of the plugs between the car and the supply might be a little dirty. If too much V drop, then wouldn’t current go up?
