How Many Amps Can Wire Handle in Mobile, Marine & Off-Grid Electrical Systems?

Comments · 49

• RO

  @robbehr8806 · 2 years ago

  Just the right video at just the right time! I live in Arizona just west of the Phoenix metro. Out here, one big issue is heating of RV electrical pedestals. Yes, during summer in the desert, an RV pedestal is like an engine compartment. Because a pedestal can reach 160F from sunlight alone, wiring has to be upgraded regarding insulation temperature range and de-rated regarding current. Now, I can just send a link to this video, rather than giving a long-winded explanation.

  7

• GK

  @GK49245 · 2 years ago

  Good summary and rules of thumb. Recommend every DIY electrician have and use a current copy of RVIA LV, ABYC E-11, and NFPA-70 for all wire sizing. As you described, you must address the debating issues of continuous loads, temperatures, etc. Especially helpful that you mentioned the temperature issue as we seen Van DIYers who under size wiring to roof top ACs, fans, lighting, etc. where the rooftop temperatures are much higher than walls. Thanks for sharing another excellent episode.

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• ER

  @EricLewis-m5n · 2 weeks ago

  Great 👍

• JU

  @junkerzn7312 · 2 years ago (edited)

  In solar / battery systems, for DC, the voltage drop definitely overrides everything else, but another factor is just straight-out thermal cycling of terminals and conductors adding unnecessary heat and stress to equipment, particularly on DC systems where large capacitors are present near the terminal whos lifespans are impacted by heat transmitted via cabling. &nbsp;And in mobile applications you don&apos;t really want any of your wiring to actually hit 90C anyway (or even 60C to be honest). &nbsp; You still use 90C+ rated wiring, but shoot for actual temperatures of 60C or lower.<br><br>The biggest sizing problems occur at lower system voltages. &nbsp;In a 12V system, it doesn&apos;t take very much voltage drop before you are quickly exceeding a 10% loss in power transmission. &nbsp;At the same time, the cabling can wind up getting just way too thick (and expensive) to deal with it. &nbsp;People often fudge and allow larger losses and more heat than desired.<br><br>But at 24V or 48V there is no reason to use anything but the most conservative wire sizes, because so much more power can be transmitted. &nbsp; One isn&apos;t forced to go into the AWG 0&apos;s and cabling losses due to voltage drop wind up being less than 2%. &nbsp; And similarly for solar panel wiring.<br><br>In my case, in terms of the amount of continuous current that I want to support without having to deal with large losses or heat, &nbsp;as a rule of thumb I use 2 AWG for 100A (roughly 5000W @ 51.2V), 12 AWG for 10A, 10 AWG for 20A, and 6 AWG for 35A.<br><br><br>-Matt

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• CY

  @cyclemoto8744 · 2 years ago

  Great info. Thanks for sharing. Cheers

• JO

  @jorgeanchia6914 · 2 years ago

  Excellent information!

• TI

  @timf6916 · 2 years ago

  Good information

• CS

  @csmetrustee · 2 years ago

  Romex must be sized using the 60 degree column in the NEC. Please look at article 334.

  1

• CA

  @carrelw4755 · 1 year ago

  Why isn&apos;t wire teflon insulated jacketed as opposed to PVC? Also why not pre-tinned?

• JU

  @Just_An_Idea_For_Consideration · 2 years ago

  What is recommended grounding wire awg size for a solar system?<br>for 200Amp AC ?<br>for 600Amp Rack (6x100Amp) DC ?<br>for ground wire from grounding rack 300 feet from inverters, to run ground wire from rack to inverters ?

• SA

  @sarachan300 · 9 months ago

  When researching this, I find that there are a lot of self proclaimed experts out there spreading misinformation. For a 1/0 wire most google search results will tell you it can only handle about 130A without mentioning temperature ratings or wire length. 1/0 is a very thick cable. &nbsp;Thanks for the detailed info.

• MO

  @MosheHagshur · 2 years ago

  Hi Nate, what happened to your cable and accessories store?