Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 06-05-2009, 14:32   #16
Registered User

Join Date: Sep 2006
Location: Keswick, ON Canada
Boat: Islander 36
Posts: 81
a couple of notes that I think may help (if I am right):
Martinini - you are lucky that they have not wired your boat with speaker or telephone wires. Some of wires on my boat are 22awg!!!??? I will replace them this spring.

s/v Jedi - I am not sure that if you use two cables instead of one - each of the two will carry 1/2 load. It happens extremely rarely!! In your case 2 x 2awg is approximate the size of 2/0 conductor and 60% more expensive. Just read Strigaldwir concerns and if any of this happen you are out of luck.

CharlieJ - I don't know the anti-seizing NAPA's compound you use but I would suggest that you use a compound that is for electrical connections - GordMay suggested a very good one from Burndy on this forum sometime ago.

hellosailor - I do not know what you meant by "star washers" but using "tooth washers" or "bellevile type" on heavy current connections is a very good idea .. if you can get stainless steel or copper.
__________________

__________________
Rodz is offline   Reply With Quote
Old 06-05-2009, 16:17   #17
Marine Service Provider
 
Maine Sail's Avatar

Join Date: Jan 2007
Location: Maine
Boat: CS-36T - Cupecoy
Posts: 3,060
Here's

Below is a great online wire gauge calculator.

I plugged in 20 feet round trip, 3% voltage drop, 160 amps and it spit back 1/0 as minimum. The 2/0 you have is probably a good safe bet.

If you want more flexible marine battery cable you can locate some Berkshire wire. The stuff is nearly as flexible as welding cable and makes the Ancor stuff look like Gondola cable..

Marine Wire Size Calculator (LINK)
__________________

__________________
Marine How To Articles
Maine Sail is offline   Reply With Quote
Old 07-05-2009, 03:04   #18
Moderator Emeritus
 
GordMay's Avatar

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 31,579
Images: 240
Quote:
Originally Posted by Rodz View Post
... I am not sure that if you use two cables instead of one - each of the two will carry 1/2 load. It happens extremely rarely!! In your case 2 x 2awg is approximate the size of 2/0 conductor and 60% more expensive. Just read Strigaldwir concerns and if any of this happen you are out of luck.
... I don't know the anti-seizing NAPA's compound you use but I would suggest that you use a compound that is for electrical connections - GordMay suggested a very good one from Burndy on this forum sometime ago.
The general practice is to derate the Ampacity of Conductors in Parallel. There are tables and formulae to determine the exact figure, but I generally just use a factor of 80%.
Derating is not an issue in this case, because we are not up-sizing for Ampacity, but for Voltage Drop.

I recommend Burndy “Penetrox-A” Anti-Oxidant Joint Compound (Petroleum Base with suspended zinc particles). It has a higher viscosity (thicker) than the more ubiquitous, GB Electrical “OX-GARD” or Ideal “NOALOX” products.

I wouldn’t recommend the use of S/S Nylock nuts for electrical terminations.

See also (post #1) “Ohm’s Law & Boats:
"Ohm's Law & Boats"
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is offline   Reply With Quote
Old 07-05-2009, 22:04   #19
Do… or do not
 
s/v Jedi's Avatar

Cruisers Forum Supporter

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 9,198
Quote:
Originally Posted by Rodz View Post
s/v Jedi - I am not sure that if you use two cables instead of one - each of the two will carry 1/2 load. It happens extremely rarely!! In your case 2 x 2awg is approximate the size of 2/0 conductor and 60% more expensive. Just read Strigaldwir concerns and if any of this happen you are out of luck.
Rodz,

I think Gord answered this very good already but want to point out that the first criteria you must check before looking to voltage drop is the max. current a wire can carry (many people forget that... this is also the maximum size for the fuse protecting the cable). For AWG2 that is 210A outside engine room and 178A inside the engine room. So, a single AWG2 is safe for 160A. The second cable lowers the voltage drop and carries about half the current. I measured my double 4/0 cables and the current difference is less than 0.5% (1.3A at a total of 385A).

I don't know about price but 2 thinner cables can be cheaper than 1 big one for some sizes... not for some other sizes; it depends on which size is sold more I think. But this "trick" becomes important when pulling the one thick cable is near impossible; the two smaller cables are much easier.

cheers,
Nick.
__________________
s/v Jedi is offline   Reply With Quote
Old 27-02-2011, 22:41   #20
Registered User
 
Extemporaneous's Avatar

Join Date: Dec 2007
Location: Canada
Boat: Corbin 39 Special Edition
Posts: 909
Burndy “Penetrox-A”

Quote:
Originally Posted by GordMay View Post
I recommend Burndy “Penetrox-A” Anti-Oxidant Joint Compound (Petroleum Base with suspended zinc particles).
Anyone know where I can pick some to this stuff up?

Thanks,
Extemp.
__________________
Extemporaneous is offline   Reply With Quote
Old 28-02-2011, 00:02   #21
Registered User

Join Date: Feb 2011
Location: South-East Australia coast
Boat: 40ft fibreglass sloop
Posts: 163
Re: Proper Wire Gauge

Quote:
Originally Posted by Ziggy View Post
As the OP points out, the 2/0 AWG is much more bulky and stiff. Of course it's his call whether the 0.25V voltage drop on a fully loaded starter is a price worth paying for using the smaller cable. Since on a sailing yacht, the engine is only an auxilliary means of propulsion and it's easy to keep a dedicated starting battery fully charged all the time, I personally would (and did) go with the smaller cable.
Weight of opinion in this thread looks not to be on your side, Ziggy, but may I suggest that IF a sailor suspects that his existing installation has battery-to-starter cable that is on the small side, he could pack truck-size jumper leads in the boat. If the situation arises where the battery is a bit low, and the engine recalcitrant, then clip on the jumper leads to reduce voltage drop for that occasion.

Marqus
__________________
Marqus is offline   Reply With Quote
Old 28-02-2011, 04:38   #22
Moderator Emeritus
 
GordMay's Avatar

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 31,579
Images: 240
Re: Proper Wire Gauge

Burndy products are available at wholesale electrical distributors like Wesco, Gescan, Guillivan, Westburne, Nedco & etc.
See ➥ Burndy® : Distributors
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is offline   Reply With Quote
Old 28-02-2011, 08:59   #23
Registered User
 
Extemporaneous's Avatar

Join Date: Dec 2007
Location: Canada
Boat: Corbin 39 Special Edition
Posts: 909
Re: Proper Wire Gauge

Quote:
Originally Posted by GordMay View Post
Burndy products are available at wholesale electrical distributors like Wesco, Gescan, Guillivan, Westburne, Nedco & etc.
See ➥ Burndy® : Distributors
Thanks Gord.
Searched the Internet, but not Burndy site.

Cheers,
Extemp.
__________________
Extemporaneous is offline   Reply With Quote
Old 28-02-2011, 10:44   #24
֍֎֍֎֍֎֍֎֍֎

Cruisers Forum Supporter

Join Date: Apr 2006
Posts: 13,033
Re: Proper Wire Gauge

extemp-
Probably Grainger, McMaster, maybe even FastenAll. Or your local yellow pages under "electrical supply". Anyplace that is in the business (as opposed to being a BigBoxChain) should have it.

I've also used some of my NeverSeize on battery contacts. Maybe it isn't kosher, but it is fine metal dust in a petroleum base, very similar product, seems to prevent corrosion without causing any problems. 10? years and counting, knock wood.<G>
__________________
hellosailor is offline   Reply With Quote
Old 28-02-2011, 23:03   #25
Registered User
 
Extemporaneous's Avatar

Join Date: Dec 2007
Location: Canada
Boat: Corbin 39 Special Edition
Posts: 909
Re: Proper Wire Gauge

Quote:
Originally Posted by hellosailor View Post
extemp-
Probably Grainger, McMaster, maybe even FastenAll. Or your local yellow pages under "electrical supply". Anyplace that is in the business (as opposed to being a BigBoxChain) should have it.

I've also used some of my NeverSeize on battery contacts. Maybe it isn't kosher, but it is fine metal dust in a petroleum base, very similar product, seems to prevent corrosion without causing any problems. 10? years and counting, knock wood.<G>
Thanks,
Extemp.
__________________

__________________
Extemporaneous is offline   Reply With Quote
Reply

Thread Tools
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
Broken gauge? sloopdavidb Engines and Propulsion Systems 1 29-08-2008 01:46
Battery Cable Gauge Aqua Vitae Electrical: Batteries, Generators & Solar 17 27-06-2008 10:15
Temp Gauge/Sender ??? drh1965 Engines and Propulsion Systems 9 13-01-2008 21:22
Fuel Gauge Problems Geno53 Engines and Propulsion Systems 4 12-01-2006 11:32
inverter wire gauge jerry f Electrical: Batteries, Generators & Solar 3 25-07-2005 18:49



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 09:05.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.