"Using 2 smaller cables that when added together will give you the capacity of the required larger cable is a no no. If at some point in the future you get a poor connection on one of the 2 cables the remaining good cable will try to carry the load and can overheat."
Good point and you are right, it cannot possibly meet safety requirements for that reason.
It was a bad suggestion on my part; DON"T do it.
Welcome to the Hatteras Owners Forum & Gallery. Sign Up or Login
+ Reply to Thread
Results 21 to 30 of 35
-
Re: Battery Cable Size for 2000W Inverter
-
Re: Battery Cable Size for 2000W Inverter
You can get tinned welding cable. I believe the problem with it is that the insulation doesn't meet requirements for oil resistance, which makes it a no-no in machinery or bilge spaces.
--- The poster formerly known as Scrod ---
I want to live in Theory, everything works there.
1970 36C375
-
Re: Battery Cable Size for 2000W Inverter
soldering battery cable is a no no on boats because of vibration. only crimping will do.
i was going to mention somethign like your diagrams.
when using multiple batteries in parralel in a bank, the best way to connect them is to connect the + on one end and the - on the other one. it spreads the load on the batteries. so if you have bank used for inverter and house, i don't see why you woudn't be able to connect them at each end.
ex. connect the inverter + and the house/start - at the battery at one end, then the inverter - and the house/start + at the battery at the other end.Pascal
Miami, FL
1970 53 MY #325 Cummins 6CTAs
2014 26' gaff rigged sloop
2007 Sandbarhopper 13
12' Westphal Cat boat
-
11-12-2008 03:14 PM #24
Re: Battery Cable Size for 2000W Inverter
Outside of finding 500 MCM marine grade wire for the negative side, I think the better choice is two grounds. I am sure there is a better way, just not sure what that is.
-
11-12-2008 10:08 PM #25Senior Member
- Join Date
- Jul 2008
- Posts
- 99
Re: Battery Cable Size for 2000W Inverter
"Out of curiosity - If your inverter is wired to 12 volt house bank, how was it done on your boat?"
My inverter is mounted a few inches away from the battery bank. It's a 2kw
Heart/Xantrex with an intermittant transfer switch issue.'68 41'TCMY
-
11-13-2008 09:30 AM #26
Re: Battery Cable Size for 2000W Inverter
So I read the bible this morning ("Boatowner's Mechanical and Electrical Manual" by Nigel Calder) for further enlightenment. He specifically calls out in inverter installation using a (very) large negative ground from battery to bus bar. The bus bar then ties to all other items like starter, DC Panels, and Inverter. I think I can use single lug on starter as my bus bar since I believe only one wire on it thus far directly from battery (I think DC panels grounds are taken off somewhere else down line). If not, I’ll add bus bar if too many cables off starter lug already.
So I will have new 500 MCM (bigger than 0000 cable) negative side battery cable made and attach to starter. Then I will have 0000 ground cable go from starter to inverter. Below is DC wiring game plan.
Note that manual calls for 300 amp Class T fuse using 250 MCM wire (next biggest size to 0000), but 0000 wire is only rated to 260 amps so I am going to use 250 amp Class T fuse instead? Rob – thanks for pointing out that manual calls for specific fuse type.
Per Keith, I will try cabletech.com to see if they carry appropriate 500 MCM tinned wire with proper marine rated insulation and follow up with this post where one can have cables this large made. I will order 0000 cable and connectors from Genuine Dealz as this is largest size they carry. If anyone thinks they see problem with design, please chime in.
-
11-13-2008 09:46 AM #27Senior Member
- Join Date
- Apr 2008
- Posts
- 252
Re: Battery Cable Size for 2000W Inverter
http://www.cableyard.com/catalog/pro...products_id=35
4/0 AWG Black Welding Cable RADAFLEX®
[F2067410-A] $4.60
4/0 AWG Black Welding Cable RADAFLEX®
Click to enlarge
RADAFLEX® 4/0 AWG Black
Radaflex® is a special Thermoplastic Elastomer (TPE) developed by Synergy Cables® as a sheathing material for flexible cables such as welding cables, flexible cords, conveyor and trailing cables - any application where outstanding toughness and durability are essential.
Cables sheathed with Radaflex® have a number of advantages:
-Ability to withstand a wide range of service temperatures from -30 to +90°C
-High resistance to wear and tear
-Outstanding chemical resistance, oil resistance, and improved weatherability
-High flexibility
Radaflex® offers a competitive alternative to many general purpose and speciality rubbers such as Polychloropene, CSP, EPR, Polyurethane TPU, and others.
My footnote: I live in Alaska and this cable type is used in really severe conditions, hope it helps.
-
11-13-2008 10:40 AM #28
Re: Battery Cable Size for 2000W Inverter
Here's a place for really big cable - Apparently wire this size is called "Diesel Locomative Cable".
http://gencable.com/index.shtml?cables/dlo.htm
-
Re: Battery Cable Size for 2000W Inverter
We use 500 MCM here in work it is HUGE don't even think about something that big it is not needed. The 0/0 is fine fror 2000 watt. I used 2/0 on my 1500 watt system.
Also you made a comment in the very beginning about using 390 amp/hrs max.
You are putting in two 275 for a max of 550 amp hr so you do not want to use more then 50% so 225 amp hr is all you should pull out so that the batteries will have a longer life.Dan
End Of The Line II
1967 34C
EOTL II Rebuild Web Page
><(((º>´¯`•.¸¸.•´¯`•.¸¸><((((º>`•.¸¸.•´¯`•.¸><(( (( º>¸¸.•´¯`•.¸¸¸><(((º>
-
11-13-2008 01:32 PM #30
Re: Battery Cable Size for 2000W Inverter
I was talking to Mike from Genuine Dealz who appears to be very well versed in the world of cables. He spent about 40 minutes on the phone with me - would not expect this kind of service from a web driven storefront.
Basically we (well, really Mike - who walked me over the phone thru NEC tables via internet he was looking at) came to deduction that Xantrex based their wire sizes on NEC table 310.16, which list wire sizes for buildings in Conduit, which is completely inappropriate for a marine/rv application. Since wire in conduit, it has to be further de-rated because of additional heat in conduit that causes additional resistence.
The correct NEC table to reference would be 400-5b, which is for single conductor open air cable. Much higher amp ratings for wires. ABYC 25 ( Pertains to inverter wiring http://74.125.45.104/search?q=cache:...abyc/A-25.pdf+ ) has even more liberal ratings then 400-5B. He also found another listing on how to install marine inverters which appears to be a written by reputable person at http://www.jtbmarine.com/installing.pdf which I am going to read.
Xantrex does not give any other options in their wiring specifications - only as I stated - 250 MCM for 0 to 6 feet, 350 MCM for 6 to 12 feet. Apparently this is beyind overkill by ABYC standards. Basically, from what I have read - NEC 310.16 has 0000 wire rated for 260 amps at 90 degrees F while ABYC has it rated for 378 continous amps inside engine spaces at 105 degrees and 445 amps outside engine spaces at 105 degrees.
I think we all agree Xantrex needs to modify their owners manual for marine installation. I am going with 0000 for entire installtion. Thanks everyone - what a pain in the rear this was.