[Tremelune]

I'm using the stock contactors and inverter, and when I turn them off, the voltage to the inverter drops swiftly. I assume it's something internal, because I didn't do anything to make this happen.

 

[eCRX]

Thanks. I'll cross that off of my list.

I'm using the stock contactors and inverter, and when I turn them off, the voltage to the inverter drops swiftly. I assume it's something internal, because I didn't do anything to make this happen.

 

[Bratitude]

This reply won’t delete

 

[Bratitude]

Gen2 inverter:
15w 61k ohm resistor bridging the dc inputs

 

[57Chevy]

15w 61k ohm resistor bridging the dc inputs

Permanently wired across the DC? So say 400VDC gives 2.6W parasitic loss instead of a NC contactor in series that has a 5W coil to open it when the inverter is on. Makes sense.

 

[remy_martian]

Contactor? Lol, wut?

A relay, not a contactor, is all that you need if you want to be completely anal retentive over every last watt. It's only 7mA flowing from B+ to B- during runtime.

They saved $0.40 on a relay, $0.30 on a socket, $20 on wiring, and $0.30 on a driver...."value engineering" heroes.

 

[eCRX]

A contactor burning 5w is probably not using an economizer?

At my first sight at the pic I was quite suprised to see something so simple. But after thinking about it, it actually seems safer and more practical to use just a resistor? One less relay to close\monitor\fail. It's probably never going to fail, and if it does, I'm guessing it would fail open?

I wonder if the inverter would annunciate a failure to discharge...

 

[remy_martian]

Your failure assumption is flawed. In DC, there's a better chance of welding the contacts together than failing open, though there's only 7mA here so neither is likely. This was a cost decision.

 

[eCRX]

Why would one choose to consume watts holding a NC relay contact open instead of using 7mA via a resistor? What is the advantage to adding the relay?

Not trying to argue, just trying to understand your point.

 

[remy_martian]

Because a relay is about 300mW at 12V vs the 2.6W at 400V. Assuming you even care about 2.3W

 

[57Chevy]

Extra cost, extra wires, extra i/o, extra failure scenarios, extra code to drive it- all to save the equivalent of about one AA battery worth of energy every couple of hours driving. Turn the radio down a little and you'll achieve the same result.

 

[remy_martian]

😂

 

[eCRX]