Emergency battery bank disconnect

[x98myers7]

I've done some searching and it appears the consensus is that disconnecting batteries while under load = arc. Makes sense. I would need to remove the load by shutting off the main AC breaker feed from the inverter, then inverter off.

I'm trying to come up with a manual emergency disconnect solution in the exceptionally rare catastrophic event and I have to physically roll my 24v Lifepo4 ESS/battery bank outside to vent.

assuming no load.... are these 175a rated Andersen style DC connectors the solution?

Amazon.com

 

[Brucey]

I've done some searching and it appears the consensus is that disconnecting batteries while under load = arc. Makes sense. I would need to remove the load by shutting off the main AC breaker feed from the inverter, then inverter off.

I'm trying to come up with a manual emergency disconnect solution in the exceptionally rare catastrophic event and I have to physically roll my 24v Lifepo4 ESS/battery bank outside to vent.

assuming no load.... are these 175a rated Andersen style DC connectors the solution?

Amazon.com

Just be very sure what you are buying there's a lot of fakes/other branded units for the real Anderson connectors. I don't think that link is the genuine version. The legit ones are rated for 175A hot plug, in an emergency disconnect situation the arc should be manageable.

I know these guys are using the real ones:

Anderson SB175 Copper Battery Cable Assembly 1/0 Gauge UL AWG w lug/terminal/clamp

www.batterycablesusa.com

 

[Brucey]

If it was my build I'd put an MNEDC250 250A midnite DC breaker between the positive terminal and the Anderson connector. Provides robust over current protection and is fully rated, can be used as a disconnect without concern (most DC breakers on Amazon cannot be).

So basically in an emergency you just turn the midnite breaker off and then disconnect the Anderson. No need to touch the inverter etc.

Not cheap but replaces a class t fuse as well.

MidNite Solar MNEDC250 250 Amp Panel Mount DC Circuit Breaker, 125 VDC

250 Amp Circuit Breaker | Panel Mount | 125v DC

www.solar-electric.com

 

[x98myers7]

I already have a T-class fuse on the positive lead, so will seriously consider the breaker instead. perfect. thank you.

 

[wpns]

24v Lifepo4 ESS/battery bank

More details? What’s the short circuit current on that bank? Or what’s the T-class fuse rated for?

 

[x98myers7]

200amps on the fuse. it's only a 2kw PV array and Growatt 3000w AiO.

 

[hwy17]

Those are knockoff Andersons. If I was going to use them I would use the name brand ones.

 

[wpns]

200amps on the fuse. it's only a 2kw PV array and Growatt 3000w AiO.

So you need a connector that will not only break 200 (plus some margin) amps, but will handle your normal (125A?) load without melting.

 

[x98myers7]

right, which genuine Andersen connectors are rated up to 280amps with appropriate cable size. so, all good. normal load is well under 60amps. occasional spikes to 85amps when the freezer compressors kick on simultaneously.