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Relay question

Posted: Sun Feb 09, 2020 12:04 pm
by johu
I am looking for a low profile, 2-pole contactor for my ChaDeMo port. I have a few Finder 30A relays here similar to this: https://www.reichelt.de/leistungsrelais ... 7.html?r=1

It has 30A switching capability. It will never switch under load. Does it mean its conducting capability is higher? By how much?
I loaded it down with 27A today and thereby found it has 1.5mOhm resistance measured from the inputs. With R*I² we get losses per contact of
  • 1.35W @ 30A
  • 2.4W @ 40A
  • 3.75W @ 50A
  • 5.4W @ 60A
3.75W sounds like it can be dissipated into the air. It would mean I could charge at 20kW. What is the max charge current of the 24kWh Leaf cells?

Alternatively I have a 400A KiloVAC contactor here.

Re: Relay question

Posted: Sun Feb 09, 2020 12:16 pm
by arber333
Maybe you want to use a Leaf 40A relay or even beffier contactor.
They have silvered contacts and magnet under its contacts to suck up any plasma arc that forms on contact opening.
viewtopic.php?f=9&t=335#p3774

or a beefier one that i took from Ampera. You can find similar items in a Leaf.
viewtopic.php?f=9&t=335#p3781