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Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: prfleming on July 05, 2015, 12:10:22 am

Title: Modified Sine vs Pure Sine Inverter
Post by: prfleming on July 05, 2015, 12:10:22 am
We just put a Keurig coffee maker in the coach and it won't turn on connected to the old original 1500 W inverter - and Tammy wants to make coffee in the morning without starting the genny...

So, does anyone out there know if a Keurig will run on a Xantrex Freedom 458 2500 with modified sine - which is what I am considering...
Title: Re: Modified Sine vs Pure Sine Inverter
Post by: Pierce & Gaylie Stewart on July 05, 2015, 01:52:27 am
Pure sine wave is only for laser printers and will run microwaves at designed speeds rather than about half as fast on the OEM inverter. Don't understand why the Keurig won't run on the OEM inverter. Are you sure you have juice to that outlet on the inverter? Electronic controls need some kind of AC but the heating element should like even DC. We use our Mr. Coffee latte maker on the OEM inverter. It has only a mechanical control but should not make a difference.

Wonder if the inverter is getting full house battery voltage? Might check the outlet voltage with a toaster running on the duplex outlet next to the test probe. What kind of battery voltage do you have with the inverter on?

Pierce

Title: Re: Modified Sine vs Pure Sine Inverter
Post by: Tom Lang on July 05, 2015, 02:20:28 am
Some devices other than laser printers also have finicky switching power supplies that require good clean sinusoidal ac power.
Title: Re: Modified Sine vs Pure Sine Inverter
Post by: John S on July 05, 2015, 07:12:48 am
Mine runs on the 2500 Watt so maybe it is drawing more then the 1500 can put out.  I can run it on a 2000 too in the Born Free.
Title: Re: Modified Sine vs Pure Sine Inverter
Post by: Barry & Cindy on July 05, 2015, 08:28:22 am
We had a small device that burned up twice on modified sine wave.  Then we found it was not the device, it was our modified sine wave inverter.  One could say that there are no devices designed for modified as all shore power is sine wave.
Modified sine wave was popular years ago when true sine wave inverters were much more expensive.
In my opinion, no one should install a modified sine wave inverter these days.  Everything runs better on true sine wave.  Had a friend with TV problems that was probably resolved with a change to true sine wave.
We changed to sine wave after we had a fire in an electronic device that may have been triggered by our old modified sine wave inverter, which then also failed.
If cost is an issue, buy a standalone true sine wave inverter, as they are much less expensive than the combined inverter/charger.  Then continue to use the charger function in the old unit, but not the inverter.
Title: Re: Modified Sine vs Pure Sine Inverter
Post by: Rick on July 05, 2015, 09:22:35 am
Peter,
  My old Kureig pulls 15 amps at 120 volts = 1800 watts.  Chances are the 1500 W inverter is being overloaded. I have heard all of the hype about mod sine wave inverters burning out all kinds of devices like electric toothbrushes, computers, TV's etc, but over 7 years with my 2K mod sine inverter, I have had no problem. However, as others have stated the cost of the pure sine wave units have come down in price to the point where if I have to replace mine it will be with a Magnum pure sine unit. Not quite sure what model I would get but here is a start for your research with one of our Foreforum commercial members;

Chargers, inverters, and refrigerators (http://www.foreforums.com/index.php?topic=22402.0#)
Good luck,
Title: Re: Modified Sine vs Pure Sine Inverter
Post by: Michelle on July 05, 2015, 09:57:42 am
We just put a Keurig coffee maker in the coach and it won't turn on connected to the old original 1500 W inverter - and Tammy wants to make coffee in the morning without starting the genny...

So, does anyone out there know if a Keurig will run on a Xantrex Freedom 458 2500 with modified sine - which is what I am considering...

Some discussion about Keurig's not playing nicely with inverters is contained in this topic (thanks to Search) Xantrex 3012 Freedom Converter/Inverter Problem (http://www.foreforums.com/index.php?topic=24194.msg193946#msg193946)
Title: Re: Modified Sine vs Pure Sine Inverter
Post by: Pamela & Mike on July 05, 2015, 10:24:19 am
I was hoping Dick would chime in as he had to have the computer part reprogramed and give an update on the exact repair and how it has helped. I don't know all the details as he has went round and round with his but it is some better as of last time we chatted.

Pamela
Title: Re: Modified Sine vs Pure Sine Inverter
Post by: prfleming on July 05, 2015, 10:48:22 am
To Pierce's point, we also have a toaster plugged into the same outlet, works fine - not used at the same time of course.

Rick, I think you might have it, the Keurig just draws too much power for the OEM inverter.

I considered getting a sine inverter just for the coffee machine, but I also want to upgrade the charger.

Those Magnum inverter/chargers look like something to check out.

Michelle, I could search - but I know how much you enjoy it!  8) Interesting so many other people have had Keurig issues.

Title: Re: Modified Sine vs Pure Sine Inverter
Post by: Roger & Susan in Home2 on July 05, 2015, 11:13:48 am
Don't forget you can get a discount on Magnum and Sterling products at Bay Marine Supply.  Ask gor Alan, tell him you are a Forum Member.

Roger
Title: Re: Modified Sine vs Pure Sine Inverter
Post by: wa_desert_rat on July 05, 2015, 03:10:32 pm
I can't imagine upgrading an inverter today to anything other than a pure sine wave inverter! Even if all the doodads you have now run just fine on MSW, what about the doodad you buy next year?

Craig
Title: Re: Modified Sine vs Pure Sine Inverter
Post by: prfleming on July 11, 2015, 11:10:59 am
Ok, so I have been doing some research and am amazed how far pure sine inverters have dropped in price. Here are some examples for under $450. Has anyone tried one of these or something similar? My plan now is to retain the Progressive Dynamics 80 amp battery charger put in by the PO, and also use the external OEM inverter transfer switch and just replace the OEM inverter. On one of these I should be able to remove the cover, drill a hole and hard wire the 120V wire connections to bypass the plug in.

MicroSolar (http://www.amazon.com/MicroSolar-2000W-Inverter-Remote-Controller/dp/B00GZBHFMY/ref=sr_1_1?s=automotive&ie=UTF8&qid=1436625559&sr=1-1&keywords=2000w+pure+sine+inverter)

Voltec (http://www.amazon.com/Voltec-10-00487-2000W-Pure-Inverter/dp/B004JPMJD8/ref=sr_1_3?s=automotive&ie=UTF8&qid=1436625883&sr=1-3&keywords=2000w+pure+sine+inverter)

SunForce (http://www.amazon.com/Sunforce-11260-2500-Watt-Inverter/dp/B0010X5KPG/ref=pd_sim_263_6?ie=UTF8&refRID=0CD0ZJPP4T2C7QDP47HR)

Power Bright (http://www.amazon.com/Power-Bright-APS2200-12-Inverter-continuous/dp/B0065M5NU4/ref=sr_1_4?s=automotive&ie=UTF8&qid=1436626864&sr=1-4&keywords=power+bright+pure+sine+wave+inverter)

Samlex (http://www.amazon.com/Samlex-America-SSW-2000-12A-2000W-Inverter/dp/B004OU99UE/ref=sr_1_2?s=automotive&ie=UTF8&qid=1436626621&sr=1-2&keywords=samlex+pure+sine+inverter)
Title: Re: Modified Sine vs Pure Sine Inverter
Post by: jcus on July 11, 2015, 11:59:38 am
Amazon.com: Xantrex PROWatt 2000 Inverter, Model# 806-1220: Automotive (http://www.amazon.com/Xantrex-PROWatt-Inverter-Model-806-1220/dp/B002LGEMOQ/ref=sr_1_2?ie=UTF8&qid=1436629779&sr=8-2&keywords=xantrex)

Moved up to this one from modified sine wave, running a chest freezer at the house from batteries and
solar panel only, noticed big difference in battery state. With modified sine wave, voltage had dropped to
12.3 by the morning, with new sine wave, never getting below 12.5. Appears compressor in freezer is
much happier with psw inverter.

Jim
Title: Re: Modified Sine vs Pure Sine Inverter
Post by: prfleming on July 12, 2015, 12:01:30 pm
Excellent suggestion. I ran across this full load test on youtube:

Xantrex Prowatt SW2000 full load test (https://www.youtube.com/watch?v=DxHfh91mcf8)

Pretty impressive little unit, I went ahead and ordered one. I will increase my OEM fuse from 175 amps to 250 amps, and will try using the OEM 3/0 inverter 12V supply cables and see if I can get full power without hitting the low voltage limit.
Title: Re: Modified Sine vs Pure Sine Inverter
Post by: Tim Fiedler on July 12, 2015, 10:15:28 pm
Thinking about the 1000w prowatt sine wave unit as dedicated inverter on dedicated battery for residential refrig when I take out my propane tank
Title: Re: Modified Sine vs Pure Sine Inverter
Post by: Jim Frerichs on July 12, 2015, 10:30:35 pm
Hi Tom,

I bought a 1000 W Prowatt and it failed within four months. Hope you have better luck, sorry.
Jim

2002 U320
Title: Re: Modified Sine vs Pure Sine Inverter
Post by: jcus on July 12, 2015, 11:57:27 pm
Thinking about the 1000w prowatt sine wave unit as dedicated inverter on dedicated battery for residential refrig when I take out my propane tank.

Tim, might go for a 1500 or 2000 watt psw inverter. I tried the 1000 watt prowatt  xantrex first on my freezer and it tripped on overload. At that time I was running 6 gauge from the batteries, so that may have been the problem, but the difference in no load draw between the 1000 and 2000 watt units in very small, so I might go overkill in this situation. By the way, have been running the 1000 watt xantrex on my small norcold frig/freezer for a year with no problems.
Title: Re: Modified Sine vs Pure Sine Inverter
Post by: prfleming on July 18, 2015, 03:05:15 pm
Just finished my Xantrex ProwattSW 2000 inverter install. After studying the existing PACS OEM inverter setup I decided the transfer relay was an integral part of the system and could not be used alone as I originally planned. So, I left the OEM inverter as-is, and added a dedicated outlet in the kitchen just for the Xantrex. Been testing and it runs the Keurig coffee maker, and our 4 slice 1800 watt toaster (could only run one side before), and runs the micro-wave much better than the old inverter.

Fyi, 4/0 extra flexible cable is available from Amazon:

4/0 awg extra flexible cable (http://www.amazon.com/Premium-Extra-Flexible-Welding-Cable/dp/B00KD27670/ref=sr_1_12?ie=UTF8&qid=1437266390&sr=8-12&keywords=4+0+awg+battery+cable)

I got mine at a local Menards for 25 ft - $125.