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Low AC voltage from Inverter

Yahoo Message Number: 7231
I recently got a digital voltage monitor and have noticed that the AC voltage coming out of the Trace inverter/charger is quite a bit lower than shore power (or generator) voltage. With no loads turned on the inverter output is about 105 volts - sometimes less than 100. This has been verified with a good quality meter.

When I turn the inverter on it seems to start at about 95V AC and after a few minutes work it way up to 105V or so.
So far, appliance operation doesn't seem to be adversely affected by the lower voltage. Are there any appliances that might be damaged by low voltage?

I didn't find this topic in the archives so thought I'd check with the group before poking around looking for corroded connections, etc.

We've been parked along the Oregon coast since the reunion rally in Sept. I'm thinking the moisture may have something to do with the problem. Corrosion?

Is there anything inside the inverter/converter box worth checking? --

Tom Harsch 2002 Allure #30791

Re: Low AC voltage from Inverter

Reply #1 –
Yahoo Message Number: 7233
Tom: Just a tip: The folks at Zantrex were very helpful in solving some inverter problems for me. Also, the inverters usually have a three year warranty if that is yoru problem

Larry

Intrigue 10762

Re: Low AC voltage from Inverter

Reply #2 –
Yahoo Message Number: 7245
Dear Tom & Maxine;

Good news... You don't have a problem with your inverter.

The inverter you have is a modifed square wave inverter, not a pure sine wave inverter. Your "good quality meter" reading is distorted by the modified square wave and is giving a reading about 20% low.
The only meter I know of that adjusts for modified square wave and gives an accurate reading is the Good Governor. My previous meter read around 100v and my new Good Governer reads 120v. Change meters and your problem will "disappear". Another option would be to spend about $2000 and upgrade to a pure sine wave inverter like Pro-sine.

Regards,

Robert

Quote from: Tom & Maxine Harsch
> I recently got a digital voltage monitor and have noticed that the

AC

Quote
voltage coming out of the Trace inverter/charger is quite a bit

lower

Quote
than shore power (or generator) voltage. With no loads turned on

the

Quote
inverter output is about 105 volts - sometimes less than 100. This > has been verified with a good quality meter.

When I turn the inverter on it seems to start at about 95V AC and > after a few minutes work it way up to 105V or so.
> So far, appliance operation doesn't seem to be adversely affected by > the lower voltage. Are there any appliances that might be damaged

by

Quote
low voltage?

I didn't find this topic in the archives so thought I'd check with

the

Re: Low AC voltage from Inverter

Reply #3 –
Yahoo Message Number: 7257
Quote from: rvrobert2003"

Dear Tom & Maxine;

Good news... You don't have a problem with your inverter.
> The inverter you have is a modifed square wave inverter, not a pure > sine wave inverter. Your "good quality meter" reading is distorted > by the modified square wave and is giving a reading about 20% low.
The only meter I know of that adjusts for modified square wave and > gives an accurate reading is the Good Governor. My previous meter > read around 100v and my new Good Governer reads 120v. Change meters > and your problem will "disappear". Another option would be to spend > about $2000 and upgrade to a pure sine wave inverter like Pro-sine.

Regards,

Robert
DUHHHHHH! Then can you explain why my $13.95 plug in meter from Camping world reads 120 Volts when Im using EITHER the genset OR the inverter??

Sully

2000 Allure 36 ft #30549

Re: Low AC voltage from Inverter

Reply #4 –
Yahoo Message Number: 7274
Hi Folks,

Here are some readings to backup what Robert is saying about measuring modified sine wave inverter output voltage:
Fluke 124 scopemeter - 119.8 vac rms, Fluke 75 multimeter started at 105.5 vac, after 5 minutes 112 vac. The "squarewave" output is not clean but has 4 spike overshoots and the tops of the square wave start at 171 volts and droop to 135 vac both positive and negative halves, also the "zero" line is not the same with +17 for the positive side and -17 volts for the negative side. The waveform does look symmetric.
An rms meter would be a lot closer and a true rms meter very close.
Fred Kovol

Quote from: rvman4u
Quote from: rvrobert2003"\[br\
\[/quote\]\[br\]] > > Dear Tom & Maxine;
>

> Good news... You don't have a problem with your inverter.
>

> The inverter you have is a modifed square wave inverter, not a

pure

Quote
sine wave inverter. Your "good quality meter" reading is

distorted

Quote
by the modified square wave and is giving a reading about 20% low.
> > The only meter I know of that adjusts for modified square wave and > > gives an accurate reading is the Good Governor. My previous meter > > read around 100v and my new Good Governer reads 120v. Change

meters

Quote
and your problem will "disappear". Another option would be to

spend

Quote
about $2000 and upgrade to a pure sine wave inverter like

Pro-sine.

Quote

> Regards,
>

> Robert
>
>

DUHHHHHH! Then can you explain why my $13.95 plug in meter from
Camping world reads 120 Volts when Im using EITHER the

Re: Low AC voltage from Inverter

Reply #5 –
Yahoo Message Number: 7275
Fred,

I marvel at the technical level you operate at. As soon as I get a coach and have a problem I will value your response.
Sully,

I sure hope you understood his explanation, It was way over my head !! :) :)
Michael

Quote from: fredkovol

Re: Low AC voltage from Inverter

Reply #6 –
Yahoo Message Number: 7281
My voltage on the inverter has always been low--less than 100. Is this not right? When I was at the factory I was complaining about the microwave not working correctly on the inverter. They made some adjustments, but still way low voltage. I am on my 3rd inverter.

Ree

Full-Timin' 2003 Allure 30852 -- Left the MH in Texas

Currently at www.eldoradoranch.com near www.sanfelipe.com.mx

Re: Low AC voltage from Inverter

Reply #7 –
Yahoo Message Number: 7366
Ree,

I posted the original question. Robert and Fred are correct - most volt meters in use do not correctly represent the AC output voltage of a modified sine wave inverter (e.g., Trace brand inverters). A series of technical notes on the Xantrex web site (www.xantrex.com) explain this and many other mysteries of inverter operation such as why some appliances work differently with inverter power than with shore or generator power.

In particular, Trace (Xantrex) _Tech Note TN2_ says a meter that is not a _True RMS_ meter will typically read between 90-105 volts.

In addition to technical notes, the web site has data sheets, user manuals, and FAQs for several inverter models now owned by Xantrex - Trace, Prosine, Freedom, ....

I also found the Trace RC7 and RC7 GS remote controls have an inverter output voltage display I'd never noriced before - it help to read the manuals. Sure enough, the RC7 GS meter reads 120 volts.

Thanks to everyone who responded.
--

Tom Harsch 2002 Allure #30791