FEEDBACK NEEDED: Round 1 Electrical Diagram

[John Ayers]

FEEDBACK NEEDED PLEASE
This is my first draft for an electrical diagram...
I'm including electrical calculations.

If you have thoughts, suggestions or questions please let me know. I'll be ordering materials in the next week or so and I want to get feedback from the established and smart members here.

Thanks!

[Dale M.]

you can cut the number of AC outlets and wiring (by a half) if you use a transfer switch with inverter on one side and shore power on other side...

Dale

[bdosborn]

Don't forget to calculate the amp draw for the 120V devices when they will be running off the inverter/12V battery

For example:
A/C - 150w/12V=12.5 amps at 12V.

The total amp draw of your 120V devices running on the inverter is 42A at 12V.

Your battery would last about an hour if you ran the A/C, fridge, DVD and TV at the same time off the battery.

Bruce

[86bigred]

i don't see why you are using i transformer to the 120 down to 12v.just run your 12 volt lights off the battery.that way you don't have to run the inverter to run your low voltage lights.

[Shadow Catcher]

You also need to figure in the efficiency or lack, of the inverter(s).

"By efficiency, we are really saying, what percentage of the power that goes into the inverter comes out as usable AC current (nothing is ever 100% efficient, there will always be some losses in the system). This efficiency figure will vary according to how much power is being used at the time, with the efficiency generally being greater when more power is used.
Efficiency may vary from something just over 50% when a trickle of power is being used, to something over 90% when the output is approaching the inverters rated output. An inverter will use some power from your batteries even when you are not drawing any AC power from it. This results in the low efficiencies at low power levels.

A 3Kw inverter may typically draw around 20 watts from your batteries when no AC current is being used. It would then follow that if you are using 20 watts of AC power, the inverter will be drawing 40 watts from the batteries and the efficiency will only be 50%.
A small 200W inverter may on the other hand only draw 25 watts from the battery to give an AC output of 20 watts, resulting in an efficiency of 80%." Down loaded from http://www.solar-facts.com/inverters/in ... ciency.php

The moral of this story is you do NOT want to use an inverter if you do not have to.

[bc toys]

are you going camping or living in this trailer seems to me you got way to many lights Iwould get a RV frig and run my A/C off shore or gin. cut out all the ac outlets exsept 1 in cabin and 1 in galley your wiring a trailer not a house

[bdosborn]

You could run the 120V TV and DVD off the battery using the right inverter without too much of a problem. Lets assume you watch a movie:

Power=Volts*Amps

60w/12v= 5 amps.

5 amps*1.5 hrs= 7.5 amp-hrs.

A Morningstar Suresine TSW inverter is 92% efficient in the 60 watt range. Morningstar is the only company I've found that publishes a graph of their inverter efficiency versus load (probably because its the most efficient inverter I've run across). It also has a very low no-load draw and a sleep function where it goes to sleep if the AC load is below 6 watts.

7.5 amp-hrs/0.92=8.1 amp-hrs

Your battery would last a couple of days using the just the DVD and lights. The A/C and fridge are what's screwing up your 12v run time. Also, by using 12V LED or fluorescent lights you could knock your amp draw for lighting down from 1.5 amps to around 0.25 amps or so.

Bruce

P.S. I had a 10" portable DVD player in the teardrop and it was around 10 watts plugged into 12V power.

[bdosborn]

P.P.S. You can buy 12V RV type lights with LEDs already installed:



Specifications:

.12 amp
1.47 watt
7 1/2"L x 4 5/16"W x 1 3/4"D

RV Light Linky

Bruce