Free 7 Day Trial RV GPS App RV Trip Planner Campground Reviews RV Maintenance Free 7 Day Trial ×


Reply
 
Thread Tools Display Modes
 
Old 05-02-2021, 01:52 PM   #1
Almost There
 
DAVEHOLMAN's Avatar
 
Join Date: Sep 2016
Location: Hesperia, CA
Posts: 75
Year: 2007
Coachwork: Thomas Saf-T-Liner
Chassis: HDX with lift
Engine: Mercedes MBE 920
Rated Cap: 22
240v water heater on 120v

I need an electrical wizard to fact check this. I read that if you connect a 240v water heater element on 120v, you draw 1/4 the rated watts.

My goal would be to minimize invertersize. I can't find 120v water heaters with less that 1400watt elements. I'm thinking of a 3000watt, 240v. That should only draw 750watts from the inverter.

I understand my recycle time will increase, but are there any other negatives? Strain on the inverter or batteries, etc?

My alternative is turning everything else off when I want hot water.
DAVEHOLMAN is offline   Reply With Quote
Old 05-02-2021, 03:26 PM   #2
Bus Crazy
 
Jolly Roger bus 223's Avatar
 
Join Date: Sep 2017
Location: Swansboro,NC
Posts: 1,637
Year: 86
Coachwork: Thomas
Chassis: Ford B700
Engine: 8.2
Rated Cap: 60 bodies
uh what?
regardless of your source ?
you will still only get 120 and never a true 230?
but i aint a sparky so i will shut up now.
just bumping this thread so the more knowledge able people will pick up the phone and help out
Jolly Roger bus 223 is offline   Reply With Quote
Old 05-02-2021, 04:22 PM   #3
Skoolie
 
DeMac's Avatar
 
Join Date: Oct 2020
Location: Florida
Posts: 238
Coachwork: International Coach Corp.
Chassis: RE-300 42ft
Engine: 466ci
Rated Cap: 90
Most 240v WH draw power from two 120v conductors and no grounded conductor. Just a ground. Where do you intend connect the 120v neutral?

Check the manufacturers voltage ratings on the elements & thermostats, might be fine.

Great if your water is already prewarmed or solar heated.
__________________
DeMac
----‐--------------------
Frederick Douglass:
"If there is no struggle, there is no progress."
DeMac is offline   Reply With Quote
Old 05-02-2021, 04:44 PM   #4
Bus Crazy
 
joeblack5's Avatar
 
Join Date: Dec 2015
Location: pa
Posts: 2,096
Year: 98
Coachwork: 1. Corbeil & 2. Thomas
Chassis: 1 ford e350 2 mercedes
Engine: 7.3 powerstroke & MBE906
Yes that will work fine.
For a 3000 watt /240 volt element will dissipate 750 watt at 110 volt.. recovery time will be about 4 times as long.

Still takes the same energy to heat a mass of water.
But you can get away with a smaller inverter and use it 4 times as long.

Normally the 240 vac is black and red . So at 120 volt you will now connect your white ( neutral) and black ( 120 vac line of your inverter to the black and red of the water heater.
Safety ground stays the same.

Good luck.

Johan
joeblack5 is offline   Reply With Quote
Old 05-02-2021, 05:04 PM   #5
Almost There
 
DAVEHOLMAN's Avatar
 
Join Date: Sep 2016
Location: Hesperia, CA
Posts: 75
Year: 2007
Coachwork: Thomas Saf-T-Liner
Chassis: HDX with lift
Engine: Mercedes MBE 920
Rated Cap: 22
Quote:
Originally Posted by joeblack5 View Post
Yes that will work fine.
For a 3000 watt /240 volt element will dissipate 750 watt at 110 volt.. recovery time will be about 4 times as long.

Still takes the same energy to heat a mass of water.
But you can get away with a smaller inverter and use it 4 times as long.

Normally the 240 vac is black and red . So at 120 volt you will now connect your white ( neutral) and black ( 120 vac line of your inverter to the black and red of the water heater.
Safety ground stays the same.

Good luck.

Johan
Excellent. And other than the inverter being used longer, which I assume will marginally shorten its life, no danger (so long as it's wired correctly)...

Thank You!
DAVEHOLMAN is offline   Reply With Quote
Reply

Thread Tools
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


» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 07:44 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
×