Author Topic: Cable Disconnect under load Options?  (Read 81 times)

DougWagner

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Cable Disconnect under load Options?
« on: April 18, 2017, 07:12:45 PM »
Hi:  My apologies if a solution is posted - I did a quick search and did not find a solution already.
We are installing a portable battery/charge controller/inverter on a cart system to a fixed 1000W array.  Intent is to be able to
unplug the DC source from the panels, and transport the cart to power a portable display unit. 

Looking for a way to interlock disconnect such that load is broken before DC connector is removed.  Will be operated by non-technical
personnel, so instructions alone not sufficient, also requires approval by electrical inspection branch (Canada)

Initially looked at Meltric connector as best solution, unfortunately cannot be UL (CSA) rated for disconnect under DC load without one-of testing fee. 

Can look at DC Load break contactor with interlock to E-box cover, but if an existing commercial solution is out there, that would be preferable.

Many thanks!

Doug W.

WizBandit

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Re: Cable Disconnect under load Options?
« Reply #1 on: April 18, 2017, 07:48:42 PM »
What brand Charge Controller?
What is the Battery & Array Voltage?
2 x 3Kw on Trailers & 1.44Kw ThinFilm on Trailer
2.16Kw roof mounted
(3) Classic 200, (2) Classic 150
(2) MidNite B17-5 6Kw Inverter Systems
Iron Edison NiFe 48V Battery

DougWagner

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Re: Cable Disconnect under load Options?
« Reply #2 on: April 19, 2017, 11:19:25 AM »
Sorry I didn't include the info:

C-controller - Midnite Classic (didn't catch specific model number)
Panel Nominal Voltage = 32V, Current approx 36 amp.

Thanks

harryn

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Re: Cable Disconnect under load Options?
« Reply #3 on: May 15, 2017, 12:54:07 PM »
I know that it is more complex in some ways, but the easiest way to pass code might be to make the connection to the cart with AC rather than DC.  That way, it is similar to any other AC cord connection you have around.  A 1 kW pure sine wave inverter in that power range is around $3-400.

I have looked around pretty broadly at DC -  rated, interlocked setups for 48 volt nominal, so up to 60 VDC peak.  While I am sure that I have missed some things, most interlocked setups are designed for high amperage / high voltage in mind, or just dealing with the arc.

So far, I have looked at offerings from midnight, newark, digikey, anderson power poles, mouser, and a few others.  You would think that a twist lock type plug would meet the requirements but I could not find one rated for a DC disconnect. 

I am very interested in this topic area, so if you find a way to do it, please post it here.

Thanks

Harry
« Last Edit: May 15, 2017, 01:02:15 PM by harryn »

WizBandit

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Re: Cable Disconnect under load Options?
« Reply #4 on: May 15, 2017, 03:54:03 PM »
You may be able to use some EV parts, this cable has the interface you desire.

https://store.openevse.com/collections/frontpage/products/j1772-cable-40a-ultra-flexible-us-only

With some ingenuity one might interface with this:
http://www.midnitesolar.com/productPhoto.php?product_ID=556&productCatName=RAPID-SHUTDOWN-SYSTEM-NEC-690.12&productCat_ID=44&sortOrder=11&act=p

Which is RSS aka Rapid Shut Down (It uses a shunt trip to turn off the Combiner), maybe use the switch in the J1772 to trip the Disco.
It would take some finaggling but could be done.

You would need to find the matching socket to the J1772 plug.
2 x 3Kw on Trailers & 1.44Kw ThinFilm on Trailer
2.16Kw roof mounted
(3) Classic 200, (2) Classic 150
(2) MidNite B17-5 6Kw Inverter Systems
Iron Edison NiFe 48V Battery