dielectric grease in battery lug?

W

williamabernathy

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Hi, All,

I plan to install an inverter using about 6.5' of 2AWG from the battery to a fuse to a switch to the inverter, then back to the battery (13' round trip).

When crimping the lugs to the 2AWG, should I daub a bit of dielectric grease into the fitting first, before crimping? Or should I leave it dry, then crimp?

Thanks for your comments.

V/R
 
I always coat the wires before I make any crimps.
 
I know it works but It seems wrong to use a dielectric
 
Especially in a boat ALWAYS use grease in the lugs. And then spray liberally with Boeshield.
 
I always use some as well

What size inverter? 2awg may be a bit small for a 6' distance unless it s a small unit. Use 2/0 for up to 1500w and 4/0 above
 
quote:
Originally posted by PascalG

I always use some as well

What size inverter? 2awg may be a bit small for a 6' distance unless it s a small unit. Use 2/0 for up to 1500w and 4/0 above

Click to expand...


Off topic. Is the gauge spec on marine wire opposite home wire. I thought the larger the number, the thinner the wire.

TIA
 
--> David

True,till you "cross zero"

In ascending diameter:

6
4
2
0
2/0
4/0

etc.
 
U
quote:
Originally posted by Radioactive

--> David

True,till you "cross zero"

In ascending diameter:

6
4
2
0
2/0
4/0

etc.

Click to expand...


Thanks. That clears it up.
 
"What size inverter? 2awg may be a bit small for a 6' distance unless it s a small unit. Use 2/0 for up to 1500w and 4/0 above"

I will use an 800w for now but may move to 1500w. Basically just running a dorm size fridge and laptop and/or Bose radio.

I'm not trying to go cheap on this, and safety's first, but it seems to me 2AWG should be enough. According to this chart from WM [IF ACCURATE], 2AWG handles up to 210 amps, which at 12vdc gives 2520 watts. And 2AWG would handle 150+ amps at 3% voltage loss over a 13 foot round trip.

http://www.westmarine.com/WestAdvisor/Marine-Wire-Size-And-Ampacity

Acknowledging that a 1500w inverter can handle a surge up to 3000w, if I used a 200 amp fuse, seems to me I should be ok with 2AWG. Going to 1AWG would handle 245 amps, or 2940w, which would be at the upper limit of a 1500w inverter's surge. And, again, if I fused it accordingly, seems to me I'd be ok.

Still, safety's first, and I appreciate the point. Not pushing back at all.

V/R
 
You need to look at the chart in the inverter manual. My Mgnum manual doesn't list size for less than 2000w unit but for 2000 watts, between 5 and 10' they recommend 2/0

For 1500 watts I would not go below 2/0.. 800w 1/0 would be as small as I d use but check the install manual
 
Make sure you use Marine Grade wire. I recall many moons ago, GeeBee compared house to marine grade and marine grade was definitely larger despite the same gauge indication.
 
House wiring is solid and definitely a no no on boats. Stay away from welding cable too which although strands is not tinned but sometimes used by cheapoes.
 
"When crimping the lugs to the 2AWG, should I daub a bit of dielectric grease into the fitting first, before crimping? Or should I leave it dry, then crimp?"

If I'm reading this right you are talking about putting the dielectric grease on the wire end before you insert it into the crimp and crimp it. Yes?

If so, since dielectric grease is nonconducting I'd say no. Crimp it first to get full contact between the wire and crimp them coat it with dielectric grease after you bolt the terminal to the wiring post.
 
I crimp it dry, then cover with heat shrink. Use good adhesive lined heat shrink color coded for the battery terminal it connects to, and heat until the adhesive begins to run out the ends. I agree to use marine wire, but also make sure you use good marine tin coated lugs such as Ancor brand.
 
dielectric is an insulator.

For connections that scrape together to make the connection such as multipin I don't see any problem. Battery lugs are compressing and scraping however.
 
From Exide Marine battery owner's manual:

--------------------------
Make sure all connections to the battery terminals are tight. Additionally,
it is important to coat the terminals and connections with a
corrosion inhibitor. The corrosion inhibitor should be reapplied
every several months. Failure to do this will result in poor
connections and wire corrosion, especially in salt water
environments. Corrosion increases the resistance in the wires,
requiring more amps to be drawn to run electrical equipment.
--------------------------

Seems to indicate the use of anti-corrosion compound on terminals prior to fastening, but the wording is unclear. Definitely coat the completed connection, however.
 
I think either I or perhaps some of you are missing his point. That's why I asked for clarification. I read it as he is asking if he should put dielectric grease in the terminal or on the end of the wire before he inserts it in the terminal and then crimps it. If that is the case, I vote no.

If not, I agree with you all. :-)
 
Definitely marine wire and definitely Ancor lugs and definitely heat shrink tubing.

I somehow had thought dielectric grease was a conductor, so I appreciate getting squared away on that point.

I'm looking to maximize electrical contact between wire and lug, so is there some other grease (or whatever) to apply onto the wire BEFORE crimping? The Boeshield T-9 mentioned above seems to be a protectant rather than conductor, so maybe applied after the crimp.

And how about recommendations for a proper crimping tool of 1/0 AWG?

Many thanks for all comments.

V/R
 
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