Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 11-11-2011, 09:16   #1
Registered User
 
Le Tour's Avatar

Join Date: Nov 2011
Posts: 30
Modified Sine Wave, Buzzing GFIs and Electrical Damage

I have been cruising for 15 years with a Heart Interface 1KW modified sine wave inverter / charger with no problems other than poor microwave efficiency. I recently purchased a 2008 boat with Freedom 30 3KW modified sine wave inverter. When under inverter power all systems operate but my GFIs make an obnoxious buzzing sound that was not present on the other boat. I plan to try replacing the GFIs to eliminate the sound but may also consider pitching the current inverter. My question rather simple, how many folks have actually had AC electronics gear damaged by the modified sine wave? My experience to date has been quite good so I'd rather not pitch a perfectly good inverter, but thought I would get some new insight. Thanks.
__________________

__________________
Le Tour is offline   Reply With Quote
Old 11-11-2011, 09:35   #2
Registered User

Join Date: Apr 2010
Location: Newport News VA
Boat: Egg Harbor sedan cruiser 1970
Posts: 829
Re: Modified Sine wave, buzzing GFIs and Electrical Damage

Replace the GFI. The new GFI dont buzz, at least mine dont with a 3000 watt MSW inverter. My GFI are totally silent. I bought them on Ebay. And remember reading the standards changed and older style ones will buzz with a MSW invertor.

If you get one that meets this then should be good.
Features:
Meets or exceeds 2008 UL 943 class A, UL 498. Protects from miswired line-load connection. Increased surge immunity. More resistance to electrical noise and to moisture corrosion.
__________________

__________________
sdowney717 is offline   Reply With Quote
Old 11-11-2011, 09:44   #3
Moderator Emeritus
 
David M's Avatar

Cruisers Forum Supporter

Join Date: Sep 2007
Location: San Francisco Bay
Boat: research vessel
Posts: 10,152
Re: Modified Sine wave, buzzing GFIs and Electrical Damage

I used to have an older inverter with a modified square wave (more technically correct term ). It destroyed a couple wall warts. Electric motors such as in power tools never quite worked right either.

I now have a 3000 watt inverter with a true sine wave. It creates no electrical noise, the microwave works normally and it also runs some pretty power sensitive oceanographic equipment controllers.

If money is not an issue, it is probably worth getting a true sine wave inverter.
__________________
David

Life begins where land ends.
David M is offline   Reply With Quote
Old 11-11-2011, 09:45   #4
Senior Cruiser

Cruisers Forum Supporter

Join Date: Mar 2007
Location: Santa Cruz
Boat: Boatless Again
Posts: 4,334
Re: Modified Sine wave, buzzing GFIs and Electrical Damage

My solution 15 years ago was to dump the GFI's. I've never damaged anything running it on the MSW inverter. However, some newer appliances don't use enough power in standby mode to turn the inverter on, so I have to plug in a small load like a cell-phone charger to trigger the inverter. I also find a separate 150 watt inverter is much more efficient for small loads like the cell-phone charger.
__________________
donradcliffe is offline   Reply With Quote
Old 11-11-2011, 13:03   #5
Commercial Member
 
CharlieJ's Avatar

Cruisers Forum Supporter

Join Date: Dec 2008
Location: St. Petersburg, FL
Boat: Gulfstar Long Range Trawler; 53'; BearBoat
Posts: 836
Re: Modified Sine Wave, Buzzing GFIs and Electrical Damage

Le Tour-
Check the Owner's manual for a list of GFCIs that Xantrex has tested and found to work with the MSW (good one David M!!) inverter/charger.

Charlie
__________________
Charlie Johnson
JTB Marine Corporation
"The Devil is in the details and so is salvation."
CharlieJ is online now   Reply With Quote
Old 11-11-2011, 20:59   #6
Registered User

Join Date: Nov 2011
Posts: 5
Re: Modified Sine Wave, Buzzing GFIs and Electrical Damage

Quote:
Originally Posted by Le Tour View Post
My question rather simple, how many folks have actually had AC electronics gear damaged by the modified sine wave?
Modified sine waves are perfectly idea for all electronics. At greatest risk are motorized appliances.

Usually coils are sealed in a varnish type material. Higher frequency anomalies (ie modified sine waves) do not vibrate that wire. Apparently your GFI coils are not sufficiently sealed. Vibration is not harmful; just annoying. At greater risk are motorized appliances and any power strip protectors.
__________________
westom is offline   Reply With Quote
Old 11-11-2011, 21:12   #7
Senior Cruiser
 
senormechanico's Avatar

Cruisers Forum Supporter

Join Date: Aug 2003
Boat: Dragonfly 1000 trimaran
Posts: 5,830
Re: Modified Sine Wave, Buzzing GFIs and Electrical Damage

I installed one of these last year.
Perfectly happy with it.

OSP 1500W PURE SINE WAVE POWER INVERTER 1500 3000 WATT | eBay

The first thing I did was add a remote switch and LEDS at the galley.
__________________
Memento,homo, quia pulvis es, et in pulverem reverteris.
senormechanico is offline   Reply With Quote
Old 11-11-2011, 23:18   #8
Registered User
 
Le Tour's Avatar

Join Date: Nov 2011
Posts: 30
Many thanks for the good replies. I purchased a newer 2010 Leviton GFCI ( could not determine if it conformed to the newer UL standard as suggested), unfortunately the buzzing was actually worse. I also noticed some buzzing coming out of the stereo receiver and TV while on inverter power but not shore power. I suppose it's decision time, drop $1200 on a pure sine wave replacement or live with the buzz. Thanks.
__________________
Le Tour is offline   Reply With Quote
Old 11-11-2011, 23:31   #9
Registered User
 
four winds's Avatar

Join Date: Oct 2010
Location: Wandering the US Gulf Coast
Boat: 78 Pearson323 Four Winds
Posts: 2,138
Re: Modified Sine Wave, Buzzing GFIs and Electrical Damage

A couple of months ago I purchased a Xantrex pure sine wave inverter from West Marine.

A 1000 watt continuous, 3000 watt surge pure sine wave inverter for $300 US including shipping. It was on sale, so I'll look to see which one I purchased and what the regular price might be.

edit,... this one. Still the same price, maybe not on sale when I purchased one. http://www.westmarine.com/webapp/wcs...classNum=50539

I was considering the Morningstar 300w unit for the same price until I saw the Xantrex.
__________________
four winds is offline   Reply With Quote
Old 12-11-2011, 01:31   #10
Senior Cruiser
 
Jim Cate's Avatar

Cruisers Forum Supporter

Join Date: May 2008
Location: cruising SW Pacific
Boat: Jon Sayer 1-off 46 ft fract rig sloop strip plank in W Red Cedar
Posts: 11,461
Re: Modified Sine Wave, Buzzing GFIs and Electrical Damage

Well, here's some more anecdotal hoo-haa:

We are still using the Heart Interface MSW 600 W inverter that I bought in 1988 or thereabouts. Has never caused any damage to devices plugged into it. Variable speed tools have jerky "throttle response", but seem to reach full speed and torque. Everything else that I have plugged into it has worked fine. I've never looked at its waveform on a scope, so don't know really what is happening, but 20+ years of faultless usage is hard to criticize. It also has very low idle current which I appreciate. Many of the true sine wave jobs draw a couple of amps at zero load, and that would be unacceptable to me, 'cause I like to leave it on 24/7.

I know that this sort of data isn't statistically important, but hey, it works for me!

Good luck and cheers,

Jim
__________________
Jim and Ann s/v Insatiable II , lying Port Cygnet, Tasmania once again
Jim Cate is online now   Reply With Quote
Old 12-11-2011, 05:05   #11
Ram
Registered User
 
Ram's Avatar

Cruisers Forum Supporter

Join Date: May 2005
Location: Cruising Greece
Boat: Cat in the med & Trawler in Florida
Posts: 2,298
Images: 27
Re: Modified Sine Wave, Buzzing GFIs and Electrical Damage

Iíve burned up 2 Dell computer plug/chargers in the last 5-6 years--they do get hotter with the modified sine wave- and both times i forgot to unplug them for many hours- so now I plug them for 1 hour max. at a time-let them cool for 15 min and plug back in= I have a vacuum cleaner, blender, food processor and power tools Iíve been using with no trouble
__________________
Ram is offline   Reply With Quote
Old 12-11-2011, 07:23   #12
Registered User

Join Date: Apr 2010
Location: Newport News VA
Boat: Egg Harbor sedan cruiser 1970
Posts: 829
Re: Modified Sine Wave, Buzzing GFIs and Electrical Damage

Mobile Power Outlets

I have a Peak 3000w MSW inverter shown here.
The GFCI does not buzz.
Perhaps differnet MSW inverters have differing wave patterns on the output.
This one runs everything. So far starts midsize fridge, 1300 watt microwave, all variable speed tools and fans. The microwave is louder than on utility power and the fan has a slightly different sound.


I wired in a remote switch and used a computer plug for a quick disconnect.




I also wired this into the boat outlet circuit using a 20 amp DPDT switch on-off-on to flip the hots and neutrals.
So I have a shore-gen switch to select between shore and genset. Then on the outlet circuit from the breaker panel I can select shore-gen power OR inverter power. So right next to each other, I have 2 switches and 2 LED. The LED lights up when the inverter puts out 120 volts. The other LED lights up when the outlet circuit is powered.

This inverter shuts down if the load exceeds the 6000 watt surge capacity

This is the GFCI I got off ebay and works with no buzz.

http://www.ebay.com/itm/GFCI-Outlets...ht_1161wt_1066

110 volt LED lights, good deal here. Also they have 12 volt led look the same.
http://www.ebay.com/itm/290571856826#ht_3221wt_1216
__________________
sdowney717 is offline   Reply With Quote
Old 12-11-2011, 07:53   #13
DoÖ or do not
 
s/v Jedi's Avatar

Cruisers Forum Supporter

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 9,198
Re: Modified Sine Wave, Buzzing GFIs and Electrical Damage

Get the pure sine inverter. Do not compare the old Heart Interface units with current Xantrax cr*p. There's plenty of threads on this forum to find out the reasoning behind this.

I would stay far away from any new Xantrex units for the time being. I took my loss a year ago and replaced the 3kW Xantrex with a Victron unit. Completely cures the situation.

cheers,
Nick.
__________________
s/v Jedi is offline   Reply With Quote
Old 12-11-2011, 13:26   #14
Marine Service Provider

Join Date: Oct 2011
Posts: 1,205
Re: Modified Sine Wave, Buzzing GFIs and Electrical Damage

Some inverters use the old c-form transformer, and they buzz.

Newer better quality inverters use a toroidal transformer, and they don't buzz....as bad, if at all.

MSW, or Pure SW, will buzz if they use the c-form transformer.

Lloyd
__________________

__________________
FlyingCloud1937 is offline   Reply With Quote
Reply

Tags
electrical

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

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




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 12:02.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.