openinverter forum

So 2 weeks ago I welded both my contactors by switching them on without precharging. They were then permanently closed.

So I decided to take a look inside
So, the connection to the top is removed first. Its two short right angle bus bars. Then the actual contacts into the relay are exposed.
The contacts are inside a ceramic hull. Strangely it says "120A". Is that the rated continuous current? The fuse is 3x that. Hmm.
The inside of the top shell contains some magnets to divert arcs away. So the relays should be able to interrupt substantial current without damage.
Now some brute force was needed to get inside the ceramic. Vice helps. Indeed the copper bar was welded to the copper poles. You can see the circular burn mark on the connector bar.
Current is conducted via this roughly 5x2mm copper bar. The actuator is spring loaded and moves by about 2mm. So 4mm spark gap in total when the relay is open.

So that's what is in there.

Gap is smaller than what I was thinking..

I wonder if you could un-stick the contactor without tearing it apart by tapping with a hammer and punch at the cylindrical copper contacts with the relay placed on a soft surface.

Could you determine if they are filled with an inert gas?

celeron55 wrote: ↑Thu Oct 07, 2021 3:37 pm I wonder if you could un-stick the contactor without tearing it apart by tapping with a hammer and punch at the cylindrical copper contacts with the relay placed on a soft surface.

I just did tap it with a hammer and it indeed came loose! I just held in my hand (=soft surface) and tapped. Now it is infinite resitance again and I can hear it switching.

And update on that again. I pulled out another pair of welded relays and they did not come loose by tapping. I think they are welded stronger. Last time it was a software error that would cause the relays to come on in charge mode without precharging. But at least there was the 200ms boot loader time to do a bit of precharging.
This time the relay driver had failed shorted and switched on the positive contactor immediately.

I apologize for resurrecting this old thread, but I can not find a datasheet for this Panasonic AEV6505A contactor nor it's sibling the AEV6501A anywhere, and what I am looking for specifically is it's 30 second current rating, and this Panasonic Ordering Information legend does not jive with the part numbers on these beasts