Help with DC disconnects on a larger system.

OutBack's newest innovation in balance-of-system components

Moderators: OutBack Moderator Team, OutBack

Post Reply
offgridfarmer
Forum Member
Posts: 19
Joined: Sat Jul 28, 2007 7:23 am
Location: lost in the wood, VA

Help with DC disconnects on a larger system.

Post by offgridfarmer »

Help with DC disconnects on a larger system.

Currently I have 2 PS4 with 6 VFX3648 inverters (3 in each PS4). IÔÇÖm planning on added 2 more in a few years when the parents get old and move in.

Where I need the help is where I need a DC distribution box
(4) 48 volt 850 amp hours Exide fork lift batteries; fused T rated 250A wire
(1) 5000 watt hydro plant; fused T rated 125A
(4) 4 sets of wires (4+, 4-) that run out to the 2 PS4ÔÇÖs
(2) Move 2 MX 60ÔÇÖs out of one of my PS4ÔÇÖs into the distribution box
(2) MX60ÔÇÖs currently not installed.

Currently I have the batteries and the hydro plant running in to one side of plywood box there they run through the T rated fuses. One the other side of the fuses they run into my copper bus and then into the 2 PS4DC boxes. The only disconnects I have would be pulling a fuse or the incoming power disconnects in the 2 PS4DC ((4) 250A ÔÇô 2 in each DC box).

I have seen some 250 breakers / disconnects by other companyÔÇÖs but the wall space they take up.

My current thought is to get Flexwear 1000. But I donÔÇÖt know it Outback makes a bus that will work with my power requirements or if it has the needed room. I plan on keeping my T rated fuses before the breakers.

So far I do think my best option with looking at Outback and non Outback products is to cut up a Flexwear 1000. I would think to mount the T rated fuses, them the Flexwear 1000 as disconnects, and then the bus bars. I would not use disconnects on the output the 2 PS4DCÔÇÖs but would still use the (2) 250 amp breakers in each PS4.



I would like a lot of feed back.
I know by looking at what I have posted my system is not properly balanced but, dump power at least twice a week in the early morning. IÔÇÖm only using about 25% of my batteries.
User avatar
mvrck
Forum Czar
Posts: 615
Joined: Mon Oct 17, 2005 10:03 am
My RE system: 3.1 kW (BP 60W) on 2x MX60s
560W (Kaneka 60W) on 1 Classic 150
1080W (Day4) on 1 Tristar MPPT 60
GVFX3524 + PS2AC/DC, MATE, HUB4, Charles 24V 30A Charger, Generac S4001, Trimetric 2020, WattPlot, greenMonitor Lite, 400AH Bank (4 ea Rolls Surrette S530 Batteries), and a lot of other solar refuse...
Location: Austin, Texas
Contact:

Post by mvrck »

Let me ask questions:
1. You plan on adding 2 of what, inverters or 3-pack of inverters
2. You are running 120/240 or 3-ph?

Thanks

Maverick
Maverick
 
¤ Off-Grid Renewable Energy Specialist
My Outback: 3kW PV STC + MX60s + GVFX3524 + PS2 Combo = Helping Myself to the Sun!
offgridfarmer
Forum Member
Posts: 19
Joined: Sat Jul 28, 2007 7:23 am
Location: lost in the wood, VA

Post by offgridfarmer »

#1 If I do need to add any more inverters it would be 2. That would give me a total of 8.

#2 IÔÇÖm running single phase; 120 / 240.
User avatar
mvrck
Forum Czar
Posts: 615
Joined: Mon Oct 17, 2005 10:03 am
My RE system: 3.1 kW (BP 60W) on 2x MX60s
560W (Kaneka 60W) on 1 Classic 150
1080W (Day4) on 1 Tristar MPPT 60
GVFX3524 + PS2AC/DC, MATE, HUB4, Charles 24V 30A Charger, Generac S4001, Trimetric 2020, WattPlot, greenMonitor Lite, 400AH Bank (4 ea Rolls Surrette S530 Batteries), and a lot of other solar refuse...
Location: Austin, Texas
Contact:

Post by mvrck »

Okay...

1. You want to add two more inverters to one PS4
2. Consolidate 4 MX60s to one box with their own disconnects.
3. Be able to buss power from a PS4 to supply the MX60s.

I thought about it over one FAT TIRE (not two)...
1. If I were building a system from stratch, I would have rotated the PS4s 90 degrees and butted the them together. Multiple 2" diameter conduit nipples would have joined the "sides" together forming one AC cavity on the top and one DC cavity on the bottom. The Big DC cables come out the bottom in 2" conduit. The AC goes out the upper right. I would stick 2 MX60s on the left DC side and 2 on the right, or all 4 on the right via a 4" wire duct (raceway).

2. Since you don't want take it all apart, just remove the wiring for the MX60s and add the inverters to their normal home. Add another PS2 to the right side of the right most PS4 and run 2/0 cable from the big buss to a 250A breaker in the PS2. Use a big buss and terminal buss bars to connect up to four MX60s (without using GFPs, or course). You can place two MX60s on the side and two on the top. Or if you have more room to the right add 4" raceway and place them on the top.

3. You can also go with a combination of PSPV and raceway. This would be 4 feet of raceway with a PSPV on top and then the four MX60s to the right. It would eliminate the intermediate 250A breaker. The only limit is the size of the wire coming into it and the max current the PSPV breaker bus can take (100A or so?)

Send me some pictures and maybe more will come to light...
Maverick
 
¤ Off-Grid Renewable Energy Specialist
My Outback: 3kW PV STC + MX60s + GVFX3524 + PS2 Combo = Helping Myself to the Sun!
offgridfarmer
Forum Member
Posts: 19
Joined: Sat Jul 28, 2007 7:23 am
Location: lost in the wood, VA

Post by offgridfarmer »

Currently I do not want to add 2 more inverters but I want to keep the option open.

The 2 PS4ÔÇÖs are joined with nipples right now but are not sitting at 90*.

The only problem I have with taking it all apart is that it would be a 2 or 3 day job with out power. Yes I do have a generator but IÔÇÖm thinking this might be the way to go.

I donÔÇÖt have a digital camera at this time. The closest town is 30 miles and to get to a city (not very big) is about 75 miles one way.

So are you thinking to put the batteries, into one PS4 and have the positive bus in there and use the other ps4 as a negative bus? Set it up with 2 batteries going into each box with 2 sets of busses and run jumpers between them (I donÔÇÖt like this idea of 2 sets of busses).

IÔÇÖm starting to think I could use a flexware just for the breakers and use busses out side of the flexware to feed the inverters. I do know a company that can make me a UL bus box for this. The batteries, hydro, and the MX60ÔÇÖs could all be wire thought the flexwear and I would have room for wiring.

IÔÇÖll draw a pic in a few hours but itÔÇÖs off to feed some live stock and toss some wood in the boiler so my wife can do the laundry.
offgridfarmer
Forum Member
Posts: 19
Joined: Sat Jul 28, 2007 7:23 am
Location: lost in the wood, VA

Post by offgridfarmer »

I donÔÇÖt like the idea of rotating my current setup. Or using my PS4DCÔÇÖs as disconnects for my batteries, hydro, and PV because of the room in the enclosures. I want to fix this right this time so I wonÔÇÖt have to refix it when I need to two more inverters or MX60ÔÇÖs.

Long term (next 5 years) I think I will need a total of 8 inverters and 4 or 6 MX60ÔÇÖs. I know this seems to be a lot of power but with a farm, my wife, our 5 year old, one on the way, and a good possibility of parentÔÇÖs moving in I do think it would be needed. The power company will not run power out to our community and we donÔÇÖt want it anyway.


Ok I think itÔÇÖs time to start over with the train of thought.

I have 4 batteries. Each battery has a 250 A T rated fuse.
I have 2 MX60ÔÇÖs will add 2 more down the road.
I have 1 hydro plant using 125 A T rated fuse.

I need a place for disconnects.

The batteries would and hydro would pass through a set of T rated fuses.

Then I would run the wires out of the fuses in to a Flexwear 1000 and use the top set of breakers for disconnects. After the disconnects the wirers would run out to a set of busses.

One the other side of the bus bare I would run the power to the 2 PS4ÔÇÖs using (2) 250 A breakers in each of the PS4DCÔÇÖs. The 2 PS4DCÔÇÖs would be wire as normal with 3 inverters with the possibility of adding 1 more to each if needed.

As suggested (I like the idea) I would get a PS2DC and use it for MX60ÔÇÖs. I would install the GFPÔÇÖs in the Flexwear (bottom) where I would install an outback bus and negative shunt For the PV only.

I found a company that has a T rated fuse panel that will hold (4) 250A and (2) 125A.
They also have a set of busses that are rated for 2500 amps at 60 volts. I havenÔÇÖt gotten all the specs on them but I should have them at the end of the week.
Is it safe to use the Flexwear in this type of way?
I know I would not be over doing the box fill.
Is there a max wattage or amperage on the UL label for Flexwear enclosure?
Post Reply