Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 21-01-2015, 09:16   #1
One of Those
 
Canibul's Avatar

Join Date: Sep 2006
Location: Colorado
Boat: Catalac 12M (sold)
Posts: 3,218
Batt To Inverter Cable Length Question

This old boat has a couple of rusty old inverters in one of the engine rooms, installed about 8 inches over the top of the battery bank. These were Harbor Freight inverters by Previous Owner, bless his heart. One failed last year, the 2KW is still going but it's a rusty hunk and getting uglier.

I bought two new inverters, a 650 watt for day to day computer/phone recharging/ low wattage use, and a 2000 watt for full house load applications. I got remote switches for both. I also have a great location in a hanging locker inside the cabin to install them, but it's probably about 8 or 9 ft. from the battery bank location. The manual says six ft. maximum. What will I lose if I stretch that to 9 ft?
__________________
Expat life in the Devil's Triangle:
https://2gringos.blogspot.com/
Canibul is offline   Reply With Quote
Old 21-01-2015, 09:20   #2
Registered User

Join Date: Jul 2013
Location: San Diego, CA
Posts: 6,619
Re: Batt To Inverter Cable Length Question

6 more ft of cable. LOL


Just go up one size on the cable and you should be ok. It's not like you're going to draw max. power for 3 days straight, are you?
socaldmax is offline   Reply With Quote
Old 21-01-2015, 09:24   #3
Registered User
 
Stu Jackson's Avatar

Join Date: Jan 2011
Location: Cowichan Bay, BC (Maple Bay Marina)
Posts: 9,703
Re: Batt To Inverter Cable Length Question

Not really so simple, max.

The little one should not be an issue, size the cabling for the load.

The big one will be an issue, not because it's beyond the six feet, but because you'll be starting to deal with BIG cabling.

For example, our 1500W uses 2/0 cables and is six feet away, total 12 feet.

2000W for eighteen feet (9 each way) is a larger load for a longer distance requiring larger cables.

Determine the load, size the cables based on the length accordingly.
__________________
Stu Jackson
Catalina 34 #224 (1986) C34IA Secretary
Cowichan Bay, BC, SR/FK, M25, Rocna 10 (22#) (NZ model)
Stu Jackson is offline   Reply With Quote
Old 21-01-2015, 10:21   #4
Registered User
 
Lars_L's Avatar

Join Date: Jul 2011
Location: Boat: Greece Winter: Höllviken, Skåne, Sweden
Boat: Malö 116 39'
Posts: 161
Re: Batt To Inverter Cable Length Question

2000 W gives 2000 W / 12 V = 137 A
Distance between the battery and inverter 9 ' = 1.8 m
Cross sections for maximum 3% voltage drop 137 * 1.8 / 10 = 30 mm²
Lars_L is offline   Reply With Quote
Old 21-01-2015, 10:57   #5
Registered User
 
DeepFrz's Avatar

Cruisers Forum Supporter

Join Date: Mar 2006
Location: Winnipeg
Boat: None at this time
Posts: 8,462
Re: Batt To Inverter Cable Length Question

Sorry Lars, you need to take into consideration the total return distance which is 5.5 m. I don't know where you got 1.8 m for 9 ft. Its actually 2.72 m for 9 ft.
DeepFrz is offline   Reply With Quote
Old 21-01-2015, 11:33   #6
Registered User
 
Lars_L's Avatar

Join Date: Jul 2011
Location: Boat: Greece Winter: Höllviken, Skåne, Sweden
Boat: Malö 116 39'
Posts: 161
Re: Batt To Inverter Cable Length Question

Is not 0.3 * 9 = 1.8?
Sorry, but you are right it is 2.7
In this simplified counting model you count the distance only one-way.
Current 167 A
Distance 2.7 m
Wire Size for 3% voltage drop 167 * 2.7 / 10 = 45 mm²
Lars_L is offline   Reply With Quote
Old 21-01-2015, 21:46   #7
Registered User

Join Date: Jun 2013
Location: canada
Posts: 4,634
Re: Batt To Inverter Cable Length Question

4/0 cable for 2000w 10' away.


it's way more then 160a. as they are not 100% efficient. and they can probably surge 2500-3000w




the magnum manual fuses the 2000w at 300a. and requires 2/0 for 5' and 4/0 for 10'.


check the manual for yours.
smac999 is offline   Reply With Quote
Old 22-01-2015, 09:58   #8
Registered User

Join Date: Jan 2010
Location: St Michaels, MD
Boat: Cal 46-3, 46' ketch
Posts: 222
Re: Batt To Inverter Cable Length Question

If mounting inverter in multi-purpose area/ locker, just make sure you don't restrict air flow through it with anything like fowl weather gear. The inverter can quickly over heat and may result in non- recoverable failure.


Sent from my iPhone using Cruisers Sailing Forum
W3GAC is offline   Reply With Quote
Old 22-01-2015, 09:59   #9
Registered User
 
Cadence's Avatar

Join Date: Dec 2008
Location: SC
Boat: None,build the one shown of glass, had many from 6' to 48'.
Posts: 10,208
Re: Batt To Inverter Cable Length Question

Quote:
Originally Posted by socaldmax View Post
6 more ft of cable. LOL


Just go up one size on the cable and you should be ok. It's not like you're going to draw max. power for 3 days straight, are you?
Ditto, just up the wire size. They probably specified on the safe side.
Cadence is offline   Reply With Quote
Old 22-01-2015, 10:06   #10
Registered User

Join Date: Mar 2014
Location: Anacortes
Boat: previous - Whitby 42 new - Goldenwave 44
Posts: 1,835
Re: Batt To Inverter Cable Length Question

Household inverters are NOT the same as marine inverters. It is OK to use a household (or car) inverter so long as you take the AC directly off of the inverter plug. You should NEVER hard wire a non-marine inverter into your boat's AC circuits. Not sure you are doing that but FYI. S It has to do with safety - read up on it if you want to know the details. Safety as in not killing someone. Also has to do with isolating the AC grounding circuit from shore power which can cause AC leakage. Too complicated to discuss here.

Also inverters should not be installed over battery banks, especially wet cells. They will corrode very quickly. It is done but not recommended. Find a better spot.
exMaggieDrum is offline   Reply With Quote
Old 22-01-2015, 10:17   #11
Registered User
 
AfterHoursNLCT's Avatar

Join Date: Nov 2010
Location: Quaker Hill, CT (just above the US Coast Guard Academy)
Boat: Silverton 34 Convertible
Posts: 200
Re: Batt To Inverter Cable Length Question

Quote:
Originally Posted by smac999 View Post
....requires 2/0 for 5' and 4/0 for 10'.
That part doesn't add up. A smaller wire for a longer distance? I think you have it backwards...
AfterHoursNLCT is offline   Reply With Quote
Old 22-01-2015, 10:20   #12
Nearly an old salt
 
goboatingnow's Avatar

Join Date: Jun 2009
Location: Lefkas Marina ,Greece
Boat: Bavaria 36
Posts: 22,801
Images: 3
Re: Batt To Inverter Cable Length Question

Quote:
Originally Posted by AfterHoursNLCT View Post
That part doesn't add up. A smaller wire for a longer distance? I think you have it backwards...

Smaller gauge number , the bigger the wires!


Sent from my iPad using Tapatalk
__________________
Interested in smart boat technology, networking and all things tech
goboatingnow is offline   Reply With Quote
Old 22-01-2015, 10:58   #13
Marine Service Provider

Join Date: Aug 2009
Location: new orleans,la
Boat: YORKTOWN 33'
Posts: 88
Re: Batt To Inverter Cable Length Question

If you can install inverter the shortest distance to batteries you can run a/c power longer runs w/o affecting power. We have 3000 watt 3' from battery and ran a/c power cords tucked away with outlets through out our boat. Your biggest lost of power is battery to inverter. good luck...P.S. get rid of harbor freight inverters i bought couple for our big truck and shorted out and almost burnt our truck down
dandkg is offline   Reply With Quote
Old 22-01-2015, 11:01   #14
Registered User
 
Cadence's Avatar

Join Date: Dec 2008
Location: SC
Boat: None,build the one shown of glass, had many from 6' to 48'.
Posts: 10,208
Re: Batt To Inverter Cable Length Question

Quote:
Originally Posted by AfterHoursNLCT View Post
That part doesn't add up. A smaller wire for a longer distance? I think you have it backwards...
I believe we where talking dia. not AWG..
Cadence is offline   Reply With Quote
Old 22-01-2015, 11:43   #15
Eternal Member

Join Date: Jul 2006
Posts: 4,046
Images: 4
Re: Batt To Inverter Cable Length Question

smac999 had it exactly right. AWG 4/0 cable is larger than AWG 2/0, and is the proper size for a 2000-watt inverter installed about 10 feet from the batteries (one way).

Be advised also to install a proper fuse. Only three types are acceptable, in order of preference:

1. Class-T
2. ANL
3. MRBF (terminal fuse).

These should be installed as close to the batteries as possible. ABYC calls for "within 7 inches".

Bill
btrayfors is offline   Reply With Quote
Reply

Tags
inverter

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Cable Length for Inverter? CAELESTIS Electrical: Batteries, Generators & Solar 4 19-06-2009 10:40
Batt-car systems for the main Tropic1 Deck hardware: Rigging, Sails & Hoisting 21 20-03-2009 08:32
Alternator died. Cause? motor ran w/batt off? HAwkcharter Electrical: Batteries, Generators & Solar 18 12-12-2007 07:13
Inverter Out to Batt Charge In - whoops S/V Elusive Electrical: Batteries, Generators & Solar 6 13-04-2007 08:57
Finding the length of a throttle cable MelissaK Engines and Propulsion Systems 4 11-02-2005 01:54

Advertise Here


All times are GMT -7. The time now is 03:51.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.