Go Back   iRV2 Forums > iRV2.com COMMUNITY FORUMS > iRV2.com General Discussion
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
Thread Tools Search this Thread Display Modes
Old 06-29-2016, 05:34 AM   #15
Senior Member
Join Date: Sep 2012
Posts: 7,010
FWIW I'm just an old electronics technician who has had his fingers in many different aspects of the art and science. I learned early on that if I understood the basic physics then I could understand the system and that led to good break/fix or engineering results depending on who way paying me to do what at the time. The reason the utility grids use high voltage is that power loss is the current squared times the resistance. For a given amount of power there is less loss at high voltage than at high current in the same size wire. Power factor correction uses capacitors to compensate for the phase shift between the current peak and the voltage peak caused by inductive loads like big motors. FWIW it is conceivable but not normal to need to do the opposite. There are just a lot more motors than capacitive loads. ;-) From what I understand I the CG's already charge for peak loads. Having said that I suspect a lot of the issues around CG problems really stem from the local untility supplier. They do not want short term high usage loads that don't pay them for the capacity the rest of the year. If I had a seasonal operation I would be looking at some of the local generation options as a cost reduction effort. Not sure where the numbers would come out. Not sure I would bother looking too hard either as it is a pass through cost. ;-)

nothermark is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 06-29-2016, 08:55 PM   #16
Senior Member
Ray,IN's Avatar
Join Date: Aug 2001
Location: North America somewhere
Posts: 13,897
Originally Posted by CountryFit View Post
in theory, the power (v * i) consumed by an appliance on 120v should be equal to that when on battery factored by inverter efficiency. in reality, there are more than that; the current draw is much greater than what appears on paper.

the example i am giving below is my real life experience.

appliance: sharp carousel convection microwave. 1600w input, 800w output
inverter: magnum ms2812. efficiency 88 - 90%
battery working voltage: 13.0-13.4v

when the microwave is working, on paper i should expect current draw

1600 13.2 0.89 = 136a (approx.)

but i have observed it drew 154 - 158a. why was that?

one of the reasons the extra energy was used was the loss occured during current traveling. i am using #2 awg cables between battery and the inverter. while it was working, i touched the cables i could feel the warmness. the heat, another form of energy, was converted from electricity and lost to the air. this heat issue occurs on all electrical transmissions, even on the main lines at 10000+v from a power plant to the transformer stations. if i were to change the cables to #4 awg, heat will still be there but in a lesser degree.

hope this clears some of the clouds.
Isn't #4 smaller than #2 wire?

2000 Winnebago Ultimate Freedom USQ40JD, ISC 8.3 Cummins 350, Spartan MM Chassis. USA 1SG, retired;PPA,Good Sam Life member,FMCA."We the people are the rightful masters of both the Congress and the Courts - not to overthrow the Constitution but to overthrow men who pervert the Constitution. "Abraham Lincoln"
Ray,IN is offline   Reply With Quote
Old 06-29-2016, 09:07 PM   #17
Senior Member
Mr_D's Avatar
Winnebago Owners Club
Solo Rvers Club
iRV2 No Limits Club
Join Date: May 2011
Location: Vancouver, WA
Posts: 31,241
Originally Posted by MtnTrek View Post
and what about power factor correction, and why does the utility grid infrastructure use such high voltages. Do you think CGs will ever start peak demand charges..... J/K

Happy motoring.
Throw in some phase angles for fun!
2009 45' Magna 630 w/Cummins ISX 650 HP/1950 Lbs Ft
Charter Good Sam Lifetime Member, FMCA, SKP
RV'ing since 1957, NRA Benefactor Life, towing '14 CR-V
Mr_D is online now   Reply With Quote
Old 06-30-2016, 12:36 AM   #18
Senior Member
CountryFit's Avatar
Join Date: Sep 2011
Location: Between the Oceans
Posts: 4,027
Blog Entries: 3
Originally Posted by Ray,IN View Post
Isn't #4 smaller than #2 wire?
i corrected it in post #9. it should have been 2/0 and 4/0 respectively

2000 Country Coach Intrigue 40', ISC 350
2014 Ford C-Max Energi
CountryFit is online now   Reply With Quote

12 volt, power

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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
Loss of 120 volts at receptacles jvojtanic Class A Motorhome Discussions 10 07-23-2015 01:07 PM
Roadtrek versus Pleasure Way versus Winnebago ERA versus Airstream Interstate 3500 anderjer Class B Motorhome Discussions 63 10-28-2013 09:36 AM
120 volts shut down petrillo 9 RV Systems & Appliances 1 10-11-2013 01:30 PM
30/50 amp adapter, 120 volts question smiybrneyes RV Systems & Appliances 16 06-29-2012 08:52 PM

» Featured Campgrounds

Reviews provided by

Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 06:00 PM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.