| [GMCnet] Converter, charger, inverter stuff [message #258522] |
Mon, 11 August 2014 17:56  |
glwgmc
Messages: 1014
Registered: June 2004
Karma: 10
|
Senior Member |
|
|
When we pulled into the FMCA Convention site in Redmond, OR, today I smelled an electrical burn smell. Turned out it was coming from the progressive Dynamics 60 amp converter charger that had smoked itself somehow. I ordered an Iota 75 amp unit with four stage smart charging from Don Rowe Inverters (good company with generally reasonable prices) that will be delivered here tomorrow.
Just before we left I wanted to change out the modified sine wave inverter in the Royale for a 2000 watt pure sine wave unit so we could run the microwave off of the inverter when dry camping. The one I installed would not run the MW even though the power output was well above the power requirement of the microwave and the battery bank and wire sizes all should have supported it easily. Note, microwaves are normally rated by the power in watts of the magnetron which can be a lot less that the actual power required to run the microwave so always look on the back of the unit to find the real power requirement. Anyway, that 2000 watt pure sine wave inverter would not power the 12.7 amps the MW needed. The inverter kept shutting itself off with an over load warning message. Hmmmm.
I am wondering if the failing converter charger could have been fooling the inverter into thinking it was seeing more draw or less input voltage than was really there. Any thoughts from the electrically advantaged members of our forum? Don Rowe called me today to say they tested the returned inverter and could find nothing wrong. It ran their slightly larger MW just fine so I am thinking there must be some connection with the failing charger converter.
I am having them send me the bit more expensive Xantrax SW 2000 inverter which they say is a bit less sensitive to the incoming DC voltage so we will see if that helps along with the new charger converter.
When I do get this sorted out the system will be quite nice. I have an automatic transfer switch between the incoming shore power and the generator. The output from that supplies power to all the coach AC circuits and it also runs to a second xfer switch that sits between either of those AC sources and the inverter AC output. That AC line powers a series of power strips placed around the inside of the coach. The microwave and all the other AC appliances can be plugged into either one of the coach AC outlets or one of these power strip AC outlets so we can choose how to power them depending on conditions. I did not want to run all the house AC circuits off of the inverter to maintain independence in the event of a component failure.
All the LED puck lights throughout the coach run off of the house 12dc as they each have an onboard power supply. The LED Twinkie lights run off one of the power strips so they can use the power supply in their wall wart for voltage protection.
As a result the AC only will work from shore power or the generator while everything else can be powered from shore power, the generator or the inverter as we wish.
Those automatic xfer switches are worth their weight in gold. This is an easy thing to do given how the Royale is wired but requires a bit more head scratching to do the way the GMC finished coaches are wired so don't try this unless you really know what you are doing.
Jerry
Jerry Work
The Dovetail Joint
Fine furniture designed & hand crafted
in the 1907 former Masonic Temple building
in historic Kerby, OR
http://jerrywork.com
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Jerry & Sharon Work
78 Royale
Kerby, OR
|
|
|
|
| Re: [GMCnet] Converter, charger, inverter stuff [message #258523 is a reply to message #258522] |
Mon, 11 August 2014 18:15  |
habbyguy
Messages: 896
Registered: May 2012
Location: Mesa, AZ
Karma: 3
|
Senior Member |
|
|
The first thing I'd suggest you do is to let us know how many feet of what size wire is powering your inverter (both to the battery and to the ground)?
To feed my own 1000 watt (about 7 amps at 120VAC) I needed to run about 30' of 1/0 and 2/0 cable. The #4 that my coach was wired with originally fell FAR short of being able to power the inverter at full song. Inverters are notoriously finicky about having a very solid DC input, and dropping just a volt will normally be enough to cause them to error out. FWIW, the 1000 watt inverter is enough to run the antique microwave in my coach, so I'm in no big hurry to replace it.
There's no doubt that if your house batteries were not fully charged (due to the failing PD converter) your inverter also wouldn't be happy...
If you can't (or don't want to...) measure the size and length of your inverter wiring, you could just throw a voltmeter on the DC input when you're trying to fire up the microwave... if the voltage is dropping much, you've found the problem. A further check would be to do the same test at the house batteries to see if they're sagging under the load as well. FWIW, I stuck with a 1000 watt inverter because I knew that anything that drew more current than that would discharge my two house batteries in VERY short order. I figure I sized the one I have for the maximum reasonable load (microwave or vacuum cleaner), which should also keep the idling current to a minimum.
Mark Hickey
Mesa, AZ
1978 Royale Center Kitchen
|
|
|
|
| Re: [GMCnet] Converter, charger, inverter stuff [message #258530 is a reply to message #258523] |
Mon, 11 August 2014 19:17 |
k2gkk
Messages: 4452
Registered: November 2009
Karma: -8
|
Senior Member |
|
|
AND, try to locate your inverter as close to the supplying battery bank as possible! That will be as BIG help in reducing loading down of the inverter due to voltage drop.
Just as an example I used about 4 feet of #6 for a tube-type amateur radio transceiver that drew about 25A back in the 60s and 70s. Even with an unobtainable 100% efficiency, your 1 kW inverter would draw 83.333A at 12VDC input. I would estimate the draw of your inverter at 1 kW output to be OVER 100 A from the battery bank. Even running the engine at 2000 RPM with a 100 A alternator wouldn't keep up! Perhaps it's time to consider using propane stove or oven for off-the-grid camping? Either that or fire up the Onan or other genset to run your M/W for a few minutes.
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
~~ ~ D C "Mac" Macdonald ~ ~~
~ ~ Amateur Radio - K2GKK ~ ~
~ ~ USAF and FAA, Retired ~ ~
~ ~ ~ Oklahoma City, OK ~ ~ ~
~~ ~ ~ "The Money Pit" ~ ~ ~~
~ ~ ~ ~ TZE166V101966 ~ ~ ~ ~
~ ~ ~ '76 ex-Palm Beach ~ ~ ~
~~ k2gkk + hotmail dot com ~~
~ www.gmcmhphotos.com/okclb ~
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
______________
*[ ]~~~[][ ][|\
*--OO--[]---O-*
> Date: Mon, 11 Aug 2014 17:15:55 -0600
> To: gmclist@temp.gmcnet.org
> From: mark@habcycles.com
> Subject: Re: [GMCnet] Converter, charger, inverter stuff
>
> The first thing I'd suggest you do is to let us know how many feet of what size wire is powering your inverter (both to the battery and to the
> ground)?
>
> To feed my own 1000 watt (about 7 amps at 120VAC) I needed to run about 30' of 1/0 and 2/0 cable. The #4 that my coach was wired with originally fell
> FAR short of being able to power the inverter at full song. Inverters are notoriously finicky about having a very solid DC input, and dropping just a
> volt will normally be enough to cause them to error out. FWIW, the 1000 watt inverter is enough to run the antique microwave in my coach, so I'm in
> no big hurry to replace it.
>
> There's no doubt that if your house batteries were not fully charged (due to the failing PD converter) your inverter also wouldn't be happy...
>
> If you can't (or don't want to...) measure the size and length of your inverter wiring, you could just throw a voltmeter on the DC input when you're
> trying to fire up the microwave... if the voltage is dropping much, you've found the problem. A further check would be to do the same test at the
> house batteries to see if they're sagging under the load as well. FWIW, I stuck with a 1000 watt inverter because I knew that anything that drew more
> current than that would discharge my two house batteries in VERY short order. I figure I sized the one I have for the maximum reasonable load
> (microwave or vacuum cleaner), which should also keep the idling current to a minimum.
> --
> Mark Hickey
> Mesa, AZ
> 1978 Royale Center Kitchen
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
|
|
|
|
GMCforum
Search
Help
Register
Login
Home
