Converted system to 48V today

Started by Powerplay, November 02, 2016, 08:39:36 PM

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Powerplay

QuoteQuite probably the low voltage rating,  is to try to accommodate some abrasion/damage to the cable,   etc.  In the USA,  NEC dictates that insulated cable needs to be protected from damage,  by protecting it in conduit, raceway,  or other enclosures,  in most cases.

Practical comment, IMO.  Also, they're getting a 105C rating and at the high temp might change the insulation.  If one's battery bank gets to 105C they've already got some issues.
41 degrees N, 255 Ah 48V AGM, MagnaSine 4448 Inv, 3500W PV, Midnite Classic 150 A (12/6/15), Midnite Classic 150 B (4/14/16), WBjr, BTS, MNPV6 X 2, SPD X 2, Apps: Mini Split AC, Car Charger, Water pumps, Lighting, -> 48V string plan 500W, 94.5VmP, 112.5VoC, -15C - 40C TCVoC -.3%, TCIsC +.04%

Westbranch

found this...http://standards.sae.org/j1127_201210/


Standard: J1127_201210

Revised: 2012-10-18


    HISTORICAL
    Access the latest revision: J1127_201512

Issuing:

    Cable Standards Committee
    Committee Information

Publisher:
    SAE International

Pages:20
Scope:

This standard covers low voltage battery cable intended for use at a nominal system voltage of 60 V DC (25 V AC) or less in surface vehicle electrical systems. The tests are intended to qualify cables for normal applications with limited exposure to fluids and physical abuse.
KID FW1811 560W >C&D 24V 900Ah AGM
CL150 29032 FW V.2126-NW2097-GP2133 175A E-Panel WBjr, 3Px4s 140W > 24V 900Ah AGM,
2 Cisco WRT54GL i/c DD-WRT Rtr, NetGr DS104Hub
Cotek ST1500 Inv  want a 24V  ROSIE Inverter
OmniCharge3024  Eu1/2/3000iGens
West Chilcotin 1680+W to come

Vic

#17
Quote from: Powerplay on November 25, 2016, 05:28:19 PM
QuoteQuite probably the low voltage rating,  is to try to accommodate some abrasion/damage to the cable,   etc.  In the USA,  NEC dictates that insulated cable needs to be protected from damage,  by protecting it in conduit, raceway,  or other enclosures,  in most cases.

Practical comment, IMO.  Also, they're getting a 105C rating and at the high temp might change the insulation.  If one's battery bank gets to 105C they've already got some issues.

First,  while it is nice that some cables,  like MTW,  have 105 C temp ratings,  almost all of the terminals to which these cables connect will have a maximum temperature rating of 75 C (terminals as found on breakers,  busbars,  etc).

The photo does show that SAE SGT cable with large lugs installed,  BUT,  sure do hope that those lugs are designed for SAE cable,   because SAE 00 cable is about 6% smaller in diameter than is AWG.   This small diameter difference could be meaningful,  or perhaps not ...

FWIW,   Vic
Off Grid - Sys 1: 2ea SW+ 5548, Surrette 4KS25 1280 AH, 5.25 KW PV, Classic 150,WB, Beta Barcelona, Beta KID
Sys 2: SW+ 5548s, 4KS25s, 5.88 KW PV, 2 ea. Classic 150, WB, HB CC-needs remote Monitoring/Control, site=remote.
 MN Bkrs/Bxs/Combiners. Thanks MN for Great Products/Svc/Support&This Forum!!

Powerplay

6% less would be roughly 10+ less Amps capacity on 2/0.  But also it depends on how many strands wire, how it is terminated etc.  They should rate the ampacity of the wire rather than the rough diameter of the conductor, IMO.
41 degrees N, 255 Ah 48V AGM, MagnaSine 4448 Inv, 3500W PV, Midnite Classic 150 A (12/6/15), Midnite Classic 150 B (4/14/16), WBjr, BTS, MNPV6 X 2, SPD X 2, Apps: Mini Split AC, Car Charger, Water pumps, Lighting, -> 48V string plan 500W, 94.5VmP, 112.5VoC, -15C - 40C TCVoC -.3%, TCIsC +.04%

Vic

#19
Hi Powerplay,

Well,  the Ampacity IS rated for SAE and AWG.   In the USA,   NEC Ampacity,  is customarily used.   NEC ratings are fairly conservative.

The reason that I noted the Cross-sectional Area,  was to show the difference in area (and it is the area of the conductor that dictates Ampacity,  all else being equal),   AND to try to show that  the fit of lugs could be compromised,  if one was using Fine Strand AWG lugs on Fine Strand SAE cable.  A smaller cross-sectional area of a cable equates to a lower Ampacity,  while holding other variables constant.  Lug crimps might not be tight enough (and therefore higher resistance)  for poorly crimped lugs when the lugs are not designed for the cable and crimpers being used.

Would seem to me,  that the fit of the lugs would be more important,  when using the SAE cable,  than would be the lower Ampacity of the SAE cable (verses AWG).

Sometimes it is not easy to determine just what type cable lugs are designed for,  as many lugs are not well marked.

Also,  the way that SAE rates Ampacity differs from the way that the NEC rates the same gauge number of cable.

Just my opinions,   FWIW,   Vic
Off Grid - Sys 1: 2ea SW+ 5548, Surrette 4KS25 1280 AH, 5.25 KW PV, Classic 150,WB, Beta Barcelona, Beta KID
Sys 2: SW+ 5548s, 4KS25s, 5.88 KW PV, 2 ea. Classic 150, WB, HB CC-needs remote Monitoring/Control, site=remote.
 MN Bkrs/Bxs/Combiners. Thanks MN for Great Products/Svc/Support&This Forum!!

CDN-VT

Quote from: Vic on December 02, 2016, 04:21:30 PM


Sometimes it is not easy to determine just what type cable lugs are designed for,  as many lugs are not well marked.

Also,  the way that SAE rates Ampacity differs from the way that the NEC rates the same gauge number of cable.


Quality crimped / swedged , swedged on property & sealed will cause no real problems .
Problem is , Folks can't  READ anymore (over here in AME ) Wire states AWG xxxx Terminal also state's AWG xxxx over here .
Auto  sae is a sloppy joke !

Don't Get Fooled , Ya drive one , as I do also but don't fly that way
VT
Canadian Solar 350W 37.6 VOC  30.6 VMP 8.22 ISC 7.87 IMP ,-15 c +30c max  4 strings in 2 in Series for 24v Classic 150 -1020 Ah  Freezers & fridges ~~~ Second Array same panels of 3sx3 parallel for 24 V Classic 150 -440 Ah Outback Barns & out blds.
48Vdc almost done,11Strings up of 3s11P same panels