Go Back   iRV2 Forums > MOTORHOME FORUMS > MH-General Discussions & Problems
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  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 02-09-2008, 03:25 AM   #1
Senior Member
 
JavaJelly's Avatar
 
Newmar Owners Club
Join Date: Sep 2006
Location: North Java New York
Posts: 1,292
The microwave would not heat, (barely warms) under inverted power even with the batteries at full charge and the engine running. Have to start the genset to get it to heat appropriately. First, I'm sure this is really bad for the microwave and second it should work under battery power no problem.

Two things:


I thought that my batteries were going bad. However, Newmar just checked all the batteries, adjusted the inverter and cleaned all the posts. They said the batteries were in great condition. They have an electronic piece of equipment that does a complete analysis. Also, specific gravity came in great.

Secondly, I do not believe there to have been any other major draws at the time of use, e.g. toaster, hair dryer. The only thing that might have been running is the HydroHot fans.

Any ideas out there?
__________________

__________________
Scott Crompton
07 Dutch Star 4304
Sue (DW)Celia 10, Alec 8, Bella (Greyhound), Isis (Abyssinian)
JavaJelly 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 02-09-2008, 03:25 AM   #2
Senior Member
 
JavaJelly's Avatar
 
Newmar Owners Club
Join Date: Sep 2006
Location: North Java New York
Posts: 1,292
The microwave would not heat, (barely warms) under inverted power even with the batteries at full charge and the engine running. Have to start the genset to get it to heat appropriately. First, I'm sure this is really bad for the microwave and second it should work under battery power no problem.

Two things:


I thought that my batteries were going bad. However, Newmar just checked all the batteries, adjusted the inverter and cleaned all the posts. They said the batteries were in great condition. They have an electronic piece of equipment that does a complete analysis. Also, specific gravity came in great.

Secondly, I do not believe there to have been any other major draws at the time of use, e.g. toaster, hair dryer. The only thing that might have been running is the HydroHot fans.

Any ideas out there?
__________________

__________________
Scott Crompton
07 Dutch Star 4304
Sue (DW)Celia 10, Alec 8, Bella (Greyhound), Isis (Abyssinian)
JavaJelly is offline   Reply With Quote
Old 02-09-2008, 03:34 AM   #3
Community Administrator
 
Route 66's Avatar


 
Newmar Owners Club
Join Date: May 2000
Location: Newark, DE
Posts: 20,468
The first thing I would do is check the voltage at the microwave 120v receptacle, with the microwave on and off, and also on inverter power and shore power or generator power.

If you have a modified sine wave inverter, and you have the proper voltage, then I would think the microwave is damaged and will no longer work on a modified sine wave.

If you have a pure sine wave inverter, it almost has to be low voltage at the microwave receptacle when on inverter power.

The inverter will put out the proper voltage until it shuts down from low battery voltage.
__________________
Adios, Dirk - '84 Real Lite Truck Camper, '86 Wilderness Cimarron TT, 4 years as a fulltimer in a '07 DSDP, '15 Virtual RV (If I'm going to have a virtual RV, I might as well have a new one)


Route 66 is online now   Reply With Quote
Old 02-09-2008, 04:21 AM   #4
Senior Member
 
bjbkkb's Avatar
 
Join Date: Dec 2007
Location: Tampa, FL
Posts: 284
Just attended a seminar at the FMCA SEA rally on generators and electricity. The microwave lack of performance issue came up and it was said the first thing to do is check voltage.
__________________
2008 Itasca Sunstar 32 K

2005 Honda Element
bjbkkb is offline   Reply With Quote
Old 02-09-2008, 04:24 AM   #5
Senior Member
 
JavaJelly's Avatar
 
Newmar Owners Club
Join Date: Sep 2006
Location: North Java New York
Posts: 1,292
Gotta be a voltage issue as the microwave works great when on shore/genset power.
__________________
Scott Crompton
07 Dutch Star 4304
Sue (DW)Celia 10, Alec 8, Bella (Greyhound), Isis (Abyssinian)
JavaJelly is offline   Reply With Quote
Old 02-10-2008, 04:47 PM   #6
Moderator Emeritus
 
Gary RVRoamer's Avatar


 
Florida Cooters Club
Fleetwood Owners Club
Freightliner Owners Club
Join Date: Jan 2000
Location: Silver Springs, FL. USA
Posts: 13,037
Microwaves are sensitive to the wave form of the AC power some may not perform well on modified sine inverters. Sometimes they do not work at all. But if the inverter was standard equipment in your Dutch Star, then the microwave should also be compatible and I would look elsewhere for the problem.

Microwaves are BIG power consumers and it is possible the large AC current draw is dropping the voltage in your batteries almost instantly. Can you monitor the battery voltage while the inverter is running and see what happens when the micro is on?
__________________
Gary Brinck
2004 American Tradition; 2007 GMC Acadia
Homebase in the Ocala Nat'l Forest near Ocala, FL
Gary RVRoamer is offline   Reply With Quote
Old 02-10-2008, 06:44 PM   #7
Member
 
Join Date: Feb 2008
Location: USA
Posts: 55
Don't recall the source, but recently read that micowaves only receive approx. 60% of power from msw inverters. You may want to research that. Sorry that I can't be more helpful than that.
__________________
Dolph is offline   Reply With Quote
Old 02-11-2008, 02:00 PM   #8
Moderator Emeritus
 
Gary RVRoamer's Avatar


 
Florida Cooters Club
Fleetwood Owners Club
Freightliner Owners Club
Join Date: Jan 2000
Location: Silver Springs, FL. USA
Posts: 13,037
Yeah, I've seen the 60% power figure too. It probably applies to at least some brands, but not universally. It will depend on the design of the particular model. Just don't be surprised when things don't cook as rapidly when on the inverter.
__________________
Gary Brinck
2004 American Tradition; 2007 GMC Acadia
Homebase in the Ocala Nat'l Forest near Ocala, FL
Gary RVRoamer is offline   Reply With Quote
Old 02-12-2008, 03:03 PM   #9
Senior Member
 
Join Date: Dec 2007
Location: Blairsville,GA
Posts: 257
It could be the modified sine wave that causes the problem, with a true sine wave the peak voltage is something like 172 volts (can't remember off the top of my head what it actually is) and with the modified sine wave I think it caps at a much lower voltage which may not be enough to charge the high voltage capacitor in the microwave. Any engineers out there? They could explain it better, or at least confuse us more.
__________________
Hillbilly2 is offline   Reply With Quote
Old 02-12-2008, 04:10 PM   #10
Moderator Emeritus
 
Gary RVRoamer's Avatar


 
Florida Cooters Club
Fleetwood Owners Club
Freightliner Owners Club
Join Date: Jan 2000
Location: Silver Springs, FL. USA
Posts: 13,037
The lower peak voltage vs the capacitor is the explanation I read too. Makes sense to me, knowing a bit about how microwaves generate the radiation to cook with.
__________________
Gary Brinck
2004 American Tradition; 2007 GMC Acadia
Homebase in the Ocala Nat'l Forest near Ocala, FL
Gary RVRoamer is offline   Reply With Quote
Old 02-15-2008, 04:35 PM   #11
Senior Member
 
Join Date: Nov 2006
Location: Cleveland, OH
Posts: 392
Scott, my microwave makes a humming noise when powered by the inverter. I was told it was due to the MSW inverter. We only use the microwave when plugged in or the genset is running.
__________________
Jerry

Newmar Mountain Aire
JerryKelly is offline   Reply With Quote
Old 02-23-2008, 10:13 AM   #12
Senior Member
 
Damon Owners Club
Join Date: Jun 2006
Location: Middletown,OH
Posts: 183
I think you need to provide more info.
a)What size inverter
b)true sine or modified sine wave ?
c)What size uWave
Your factory info may not like modified sine wave.
Your inverter may be too small

????
__________________
Dave

Callsign: KD8W
hamdave is offline   Reply With Quote
Old 03-01-2008, 12:07 PM   #13
Junior Member
 
Join Date: Jan 2003
Location: Banks, OR
Posts: 4
As others have stated, if you have a 'modified sine wave' inverter, that explains the slow cooking. The microwave's cooking power is dependent on the peak voltage of the AC power, which is 162 with a 115 volt sine wave, and at best 140 with a 115 volt 'modified' sine wave.
__________________
2003 Cougar 278 EFS
2003 GMC Sierra CC LWB D/a Fold-a-Cover tonneau
Wayne Dohnal is offline   Reply With Quote
Old 03-01-2008, 01:24 PM   #14
Community Moderator
 
Petro's Avatar


 
Winnebago Owners Club
Freightliner Owners Club
Join Date: Dec 2003
Location: Weyauwega, WI US
Posts: 4,109
Scott;

I have not tried ours strictly on battery alone but it works well while underway. We have a combination convection/microwave and we have used both while traveling.

Don
__________________

__________________
Don & Bev Morgan Weyauwega WI, 05 Itasca Horizon 40KD, 400 HP Cummins, Delorme GPS LT 40, Toad 07 Saturn Vue AWD, Air Force One, TST 510 TPMS, Mayor of Weyauwega 2007 - 2013, Waupaca Co Board Supervisor 2010 - 2014
Petro is offline   Reply With Quote
Reply



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
Microwave work on Gen Power? Rick 2005 Dolphin 5376 National RV Owner's Forum 15 09-26-2008 04:09 PM
"Inverted" receptacle for TV on 35U Belgique Winnebago Industries Owner's Forum 11 01-19-2008 03:34 PM
Heat Pump - No Heat - 2002 Journey PULLEY MH-General Discussions & Problems 5 09-12-2006 04:07 PM
Newmar's New Inverted Mirrors Lug_Nut Newmar Owner's Forum 19 08-02-2006 07:40 AM
Heat Pump - No Heat - 2002 Journey Winnebago Industries Owner's Forum 5 12-31-1969 07:00 PM


All times are GMT -6. The time now is 12:31 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2014, vBulletin Solutions, Inc.