Xantrex 250 DC disconnect question- will the 250 amp work with MS Classic controller?

showmeshowme Registered Users Posts: 63 ✭✭

Getting ready to finally install my system components, and I just read something I need to get straight before continuing. As I was looking up the disconnect breaker, I read that the 250 amp breaker is sized to fit the Xantrex C40 PWM charge controllers. Although I have those cc's, I'm going to use Classic 150 MPPT's instead with my 48v system. Up to this point, I've been under the impression that all is well with what I have. My question is, will my MS Classics function properly with this/these 250A breakers, or do I need to switch to another size for the Classics?

What I have came from a single inverter system, so I was going to get a second (probably get two new ones and keep the old one as a back up) 250A disconnect switch, along with the CD60DC breaker for the array shut off in the same box, which i'll need two also, since this box was set up for a single array into a single inverter. Will the 250A battery disconnect breaker and the CD60DC's work? I have 8kw of panels split into two arrays feeding two Classic 150's, feeding into two Xantrex SW5548's. Thanks for any and all replies. Lee

"Knowing is not enough, we must apply. Willing is not enough, we must do."   Goethe

NOS Trace Xantrex power panel, (3) Trace Xantrex SW5548's (2 NOS in boxes, one used), Xantrex DC/disconnect, AC disconnect/conversion, Xantrex T240 Auto transformer, (3) C40 PWM charge controllers, (2 NOS, one used)  8k LG Neon 320w, (8)Evergreen  Solar 120w (960w)  , Bergey XL.1 1.5k genny, AirX 400 genny, 48v Interstate Workman batts (frozen/toast), (2) MT Solar Top of Pole 12's, (2) Midnite Solar MSPV 4 combiner boxes, (2) Midnite Solar Classic 150's and one nice Ozark hilltop to set them all.


Comments

  • VicVic Solar Expert Posts: 3,152 ✭✭✭✭
    edited February 12 #2
    Hi Lee,

    The 250 A DC breaker is for the inverter, when using 4/0 cable (breakers protect cables from overheating).

    A CD60 breaker, may be a reference that Schneider used (IIRC).

    The DC breakers for the PV in, and the cable from the Classics to batteries,  would often be MNEDC,  or MNEPV breakers,  these days. The choice of the style, will depend on how they are going to be mounted (what style of metal box),  and the desired cable size/breaker rating.

    It is not clear,  just what box is in the photo.  The busbar, with the shunt,  is for the DC negative connections from the inverters,  CCs,  etc.  The end of the shunt that is not connected to the busbar,  connects,  ONLY,  to the battery negative terminal.

    The Classics will accommodate #4 Ga,  THHN-style cable (NOT fine-stranded cable).   #4 AWG Copper cable will easily handle 60 amps. I am probably stating things,  that you already know  ...

    Are you going to use the Trace/Xantrex DC Conduit boxes, used with the venerable 5548s?
    Later,  Vic 
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH [email protected], 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • showmeshowme Registered Users Posts: 63 ✭✭
    edited February 14 #3
    Not sure what you're asking here, Vic. The box is a Xantrex DC Disconnect/Overcurrent Module. To disconnect the battery from the inverters and the array disconnects. The CD60CD switches (aka "Line LR 226229 209-1-1" per the label) are the solar array disconnects. I'm just wondering if the breakers currently in the box are compatible with Midnite Solar Classics. I've seen plenty of pics ofSW5548's paired up with Classics, but it never occurred to me that an mppt could possibly need a different size switch. Per the conduit boxes, I have no idea what you're talking about. This is mounted on a Trace Xantrex power board. There will be conduit from box to box, as you can see by the fittings in the pictures. Here's a pic of the face plate of the box.

    "Knowing is not enough, we must apply. Willing is not enough, we must do."   Goethe

    NOS Trace Xantrex power panel, (3) Trace Xantrex SW5548's (2 NOS in boxes, one used), Xantrex DC/disconnect, AC disconnect/conversion, Xantrex T240 Auto transformer, (3) C40 PWM charge controllers, (2 NOS, one used)  8k LG Neon 320w, (8)Evergreen  Solar 120w (960w)  , Bergey XL.1 1.5k genny, AirX 400 genny, 48v Interstate Workman batts (frozen/toast), (2) MT Solar Top of Pole 12's, (2) Midnite Solar MSPV 4 combiner boxes, (2) Midnite Solar Classic 150's and one nice Ozark hilltop to set them all.


  • VicVic Solar Expert Posts: 3,152 ✭✭✭✭
    edited February 13 #4
    showme,  said,  " The box is a Xantrex DC Disconnect/Overcurrent Module".

    Xantrex called the breaker boxes, used with SW+5548s,  "Conduit Boxes".  That was what I had referred to  ...

    I have no knowledge of the Xantrex box that you referred to.

    AND,  I have no direct experience with the exact CD60 breaker  --  in searching on that part number that you noted,  other than it appears to be an AIrpax brand breaker,  which was a common brand,  used in that vintage of equipment,  can find NO specs on it.

    We have used Airpax E-frame (3/4" wide) breakers,  in the past, with Xantrex "Conduit Boxes" (specifically,  the DCCB-Ls).  The thing about using the CD60 breaker,  to me,  is that the DC voltage rating of that model breaker,  may not be high enough for your PV String voltages,  when using an MPPT CC, such as the Classic.   That breaker may have been speced for use with PWM CCs.

    There may be a label on the CD60 breaker that notes the maximum voltage rating for that breaker.

    You might look at Schneider DC, E-frame breakers,  used with their CCs.  These are not too expensive,  and have a maximum DC voltage rating of 125 VDC,  which should be suitable for use with a MN Classic 150, depending on your PV String voltage:
    Schneider 865-DCBRK-60 60 Amp DC Breaker | Northern Arizona Wind & Sun (solar-electric.com)

    This is all that I have,  on this.  Good Luck,   Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH [email protected], 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • littleharbor2littleharbor2 Solar Expert Posts: 1,698 ✭✭✭✭
    The 60 amp breaker may or may not be rated for the high voltage your system is wired at.  I have a number of those breakers used in the Trace/Xantrex  disconnect panels. If you need one and are having any difficulty finding one. I would be willing to part with one.

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric,  460 Ah. 24 volt LiFePo4 battery bank. Plenty of Baja Sea of Cortez sunshine.

  • showmeshowme Registered Users Posts: 63 ✭✭

    Thanks, guys. The pic I posted didn't show up, so I re-posted it on that thread. Yeah, Vic, that's what I'm concerned about (the sizing of the original systems switches working with the Classics instead of Xantrex's C40's. I'll go ahead and pull that CD60 to see if there's more info on the other side, and also check it's voltage rating. If I'm figuring right, the strings (modules show a VOC of 40.8v and Vmpp of 33.3) are in 3's, so if I'm correct, an estimated 122.4 max voltage would fit with the 150's.

    Mike, thanks very much for the offer. But first I need to call Midnite Solar and ask them what they suggest. I'm just glad I didn't get everything together and have it run for awhile before I realized the original breakers weren't right for the Classics. Thanks again, you two. I'm still learning (and probably always will be). Lee

    "Knowing is not enough, we must apply. Willing is not enough, we must do."   Goethe

    NOS Trace Xantrex power panel, (3) Trace Xantrex SW5548's (2 NOS in boxes, one used), Xantrex DC/disconnect, AC disconnect/conversion, Xantrex T240 Auto transformer, (3) C40 PWM charge controllers, (2 NOS, one used)  8k LG Neon 320w, (8)Evergreen  Solar 120w (960w)  , Bergey XL.1 1.5k genny, AirX 400 genny, 48v Interstate Workman batts (frozen/toast), (2) MT Solar Top of Pole 12's, (2) Midnite Solar MSPV 4 combiner boxes, (2) Midnite Solar Classic 150's and one nice Ozark hilltop to set them all.


  • VicVic Solar Expert Posts: 3,152 ✭✭✭✭
    edited February 14 #7
    Hi Lee,

    Yes,  you did ask a good question,  about any possible difference twix DC breakers for PWM PV CC use,  vs those for MPPT CCs.

    MidNite has a very complete line of breakers,  but,  IIRC they have NO "E Frame" breakers.  MN, does offer an adapter, to allow using their MNEDC (Carling D series)  breakers,  in a slot in an existing box designed for the 1" wide E Frane units.  These D series breakers are available in continuous DCcurrent ratings,  up to 100 Amps:
    MidNite Solar MNBREAKER ADAPTER | Northern Arizona Wind & Sun (solar-electric.com).

    Here is a Link to the MN line of breakers  --  the Breaker Poster:
    breakers_11x17.jpg (1056×1632) (midnitesolar.com)

    Later,  Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH [email protected], 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
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