| Author |
Message |
Buddy Tennison (Buddyten)
Registered Member
Username: Buddyten
Post Number: 46
Registered: 7-2005
Posted From: 207.68.234.24
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 04, 2007 - 8:35 am: | |
I know this has been discussed, but I'm kinda dumb about things like this. What is the difference between a modified sine wave and a true sine wave? I know that one is better for running electronics, etc. I want to install some lights (flourescent) in the valances I have. I don't want to take up amps off my genset, and would like to run it off coach battery power if feasible, or maybe off the battery I use to run the genset. Is the modified sine wave acceptable for lighting and maybe a coffee pot, that type thing? I have my TV's and stereo running on standard AC power from the genset. I noted that Harbor freight has some nice looking MSW inverters for a reasonable price. We only use our coach as a tour bus on weekends, and don't do any boondocking and the like. |
Bruce Henderson (Oonrahnjay)
Registered Member
Username: Oonrahnjay
Post Number: 193
Registered: 8-2004
Posted From: 72.12.39.78
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 04, 2007 - 9:46 am: | |
Buddy, I am also dumbber than two rocks about anything with electrons, but I've been told that the basic rule is that if it runs heat (like the coffee pot you're mentioning) then MSW is OK. Things like computers and TV's (but don't forget that many things like microwaves are powered by computer chips these days) need pure sine wave. But I don't know about flourescent lights. But aren't there some good, high-efficiency 12V flourescents out there? That would give you direct lighting without the cost, heat and efficiency loss of an inverter?
(I've never tried the 12V flourescents so if someone has and they're not good, please let us know.) |
Larry Baird (Airhog)
Registered Member
Username: Airhog
Post Number: 134
Registered: 1-2001
Posted From: 71.9.81.46
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 04, 2007 - 9:47 am: | |
If you only want lights you can get 12 volt lights. I use them and they work well.
(Message edited by airhog on December 04, 2007) |
Dan West (Utahclaimjumper)
Registered Member
Username: Utahclaimjumper
Post Number: 78
Registered: 1-2005
Posted From: 208.66.38.115
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 04, 2007 - 10:23 am: | |
Buddy, I have my system split between 12V and AC, all lights are 12V including all florecents. My inverted system is MSW 5000 watt surge to 10000 watt and I use it for microwave, all kitchen gadjets, flat screen TV, all sound systems,in motion sat system, small electric heaters,ect ect. I have had this set up for ten years with only one problem, the microwave clock gains time.>>>Dan |
Jerry Liebler (Jerry_liebler)
Registered Member
Username: Jerry_liebler
Post Number: 310
Registered: 3-2005
Posted From: 67.140.167.10
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 04, 2007 - 10:29 am: | |
Modified sine wave is marketing BS for Not quite square waves. The output of an MSW inverter steps between three voltage levels, positive, zero and negative. The steps are fast and anything but smooth. Whereas the true sine wave inverters use many much smaller steps and often add 'filters' which smooth the transitions. Both output most of the output power at 60Hz but the MSW has more than 25% of it's output power in, 'harmonics', frequencies that are integer multiples of 60 hz. The true sine wave types will have less than 5% of their output power in harmonics. The harmonic power is WASTED and turned into heat in motors and transformers, so anything that involves a motor or transformer will run HOT on the MSW. Air conditioners, Microwaves, even cell phone chargers will all run much hotter and may be damaged by MSW power. On the other hand most desk top computers and most all 'heating' appliances could care less.
If you are going to run air conditioner(s) off of an inverter, a good true sine wave inverter will pay for itself in longer life, and better performnce, of the units. The true sine wave units generally have much better battery chargers built in so battery life is extended significantly also.
Regards
Jerry 4107 1120 |
Edward J. Sommers (Sommersed)
Registered Member
Username: Sommersed
Post Number: 28
Registered: 10-2004
Posted From: 148.78.155.174
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 04, 2007 - 10:36 am: | |
I am a full time RV'er that boondocks exclusively.
I've been in a RV park for only a month in the last four years. I run TV's, Microwave, computers, sat internet, sat TV, power tools, small clothes washer, and everything else on MSW.
The only thing I have noticed is that the microwave is not as efficient so If it is needed for over five minutes or so, I use my nice and quiet Honda 2000i for the job. Otherwise the 500 watts of solar panels, coupled with 440 AH of golf cart batts work just fine hooked to my 1800 watt MSW do the job. |
Luvrbus (Luvrbus)
Registered Member
Username: Luvrbus
Post Number: 191
Registered: 8-2006
Posted From: 74.33.62.149
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 04, 2007 - 11:00 am: | |
One thing i know about the MSW that i have had for years it will kill a 32in LCD TV.i am upgrading to the true sine when i can get a inverter with enough watts without being stacked for a 12v system |
Don Evans (Doninwa)
Registered Member
Username: Doninwa
Post Number: 95
Registered: 1-2007
Posted From: 66.45.165.58
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 04, 2007 - 11:59 am: | |
"I don't want to take up amps off my genset, and would like to run it off coach battery power if feasible, or maybe off the battery I use to run the genset."
Lighting would add little to the load on your genset. Sounds like you run the genset all the time anyway, why not use it? Maybe there is something I don't understand about the way you use your bus. Maybe more info on how you use the genset would help. Do you normally run it all the time?
If you use an inverter something has to be suppling power to the batteries, either the engine running or the genset. I would not use the genset battery and risk running it dead and not being able to start the genset. I would not use the engine start batteries and risk running them down unless the only time you use the lights is when the engine is running. Then there is the issue of battery type. If you are using them when the engine is off they really should be deep cycle types. |
Chuck Newman (Chuck_newman)
Registered Member
Username: Chuck_newman
Post Number: 246
Registered: 1-2005
Posted From: 63.145.177.245
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 04, 2007 - 2:44 pm: | |
Buddy, having evaluated and used both types inverters since 1972 (including true square wave), a MSW will serve your specific needs fine. The key is to stay with name brands like Xantrex, Trace, and others that cater to RV's and buses. Their MSW inverters have more "voltage steps" and more filtering, better regulation, etc. Beware of Harbor Freight, Coleman, and others. For certain applications they are fine. But for electronic equipment power, your mileage will vary.
Generally, the larger the output AC wattage of the inverter will dictate the larger 12 or 24 vdc current output for your batteries. And the better name units will have multi-stage smart battery chargers so you won't cook your batteries. The cheaper inverters don't even offer integrated battery charging.
I'm going to use a top of the line Xantrex sine wave inverter. The ironic part is it is not a pure sinewave output -- rather a multi-stepped MSW. You can't believe the marketing hype. You must read the specifications to really understand what you are buying.
I could save $1K bucks and get by with a very good Xantrex MSW, but I'm going with the "sine wave" model for two reasons: 1) More battery charging current than their largest MSW and 2) This model offers load sharing which comes in handy at times when you are hooked to a 15 amp circuit. |
Luvrbus (Luvrbus)
Registered Member
Username: Luvrbus
Post Number: 192
Registered: 8-2006
Posted From: 74.33.62.149
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 04, 2007 - 3:04 pm: | |
Chuck, i going with the Mangum inverter for one reason that is made in the USA.You have to be real careful on some the models of Xanterx the RS 2000 and RS 3000 are made in China.This is one reason Dick Wright doesn't sell Xantrex any longer.FWIW
(Message edited by luvrbus on December 04, 2007) |
Jerry Liebler (Jerry_liebler)
Registered Member
Username: Jerry_liebler
Post Number: 311
Registered: 3-2005
Posted From: 67.140.167.10
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 04, 2007 - 6:49 pm: | |
Chuck,
All but a very few very low power true sine wave are what you call multi-step. The important thing is the output distortion. A stepless true sine wave would be VERY inefficient. The Trace SW 2512 and SW4024 use about 20 voltage steps and have under 5% distortion and still deliver effeciency over 90 %. These particular models offer power suplementation where the load can be heavier than the shore cord with the difference coming from the battery. Regretably this feature is only available in these models. I'd rather have the feature than made in America.
Regards
Jerry 4107 1120 |
Luvrbus (Luvrbus)
Registered Member
Username: Luvrbus
Post Number: 194
Registered: 8-2006
Posted From: 74.33.62.149
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 04, 2007 - 7:43 pm: | |
Jerry,I looked for the SW2512
but it has been discontinued and I don't know why. but i am not going to buy a inverter that is not being made any longer anyway when trying to upgrade my system.the RS 3000 is a good buy but I have enough made in China stuff in my life. and FWIW Mangum has a new line coming in Mar 08 just my way
(Message edited by luvrbus on December 04, 2007)
(Message edited by luvrbus on December 04, 2007)
(Message edited by luvrbus on December 04, 2007) |
Jerry Liebler (Jerry_liebler)
Registered Member
Username: Jerry_liebler
Post Number: 312
Registered: 3-2005
Posted From: 67.140.167.10
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 04, 2007 - 10:25 pm: | |
Luvrbus,
I think you'll find that the SW2512MC is no longer 'discontinued'. It is certainly available from a good number of sellers.
Regards
Jerry 4107 1120 |