Energy Management System

I must pose this as a question rather than a statement. When any inverter crosses a load threshhold it used to lose it's stepped pseudo or true sine wave emission and defaulted to square wave ouput.

How would an inverter respond to having it's power source in this case a motor driven generator inverter, deliver square wave AC to it's input i.e. AC to be reverted to DC?

Would then this be the "fault" of the inverter or the supply?

I would keep it in mind...

MrWizard,

Anytime a thread offers interesting information I find it useful.

With the Cobra 2500 watt and the PD 40 amp I could do double conversion all day long. With the Magnum I tried it just once and the reverse polarity fuses popped immediately.

I looked for a tripp lite in the 3000 watt class--but they don't offer a 12 to 120 in pure sine wave.

My electrical bay compartment is outside access
I do leave it open during the day while charging in hot weather
But not in cold weather, not normally needed in early March at night
I like I said, the inverter was the load that killed the wfco
Running the heater did not hurt the inverter
Both in the same compartment (and that compartment housed the OEM Freedom 10 combo unit for many years)
Not all converters or inverters are the same quality

Of course this is PT's thread
I was only making a comment regarding my inadvertent double conversion of power

I have 'so far' avoided making that mistake a second time

Double conversion can done using two devices
But a combo unit only does one or the other
And Don did say it was charging the batteries before the failure

This conversion conversation is regarding possibilities of future use

pianotuna wrote:
Hi BFL13,

And what brand name is that converter?

BFL13 wrote:
My 100 amp converter/charger will run at constant 103 amps for at least an hour with no tapering of the amps.

It is a PowerMax PM3-100 that I have had for a few years now. I have set it to 14.8v using the internal pot, which killed the 3-stage profile, so I have to manually turn off the 100 when the batts are done, and use a different converter at 13.6v after that.

Actually, I find that if I leave them at 14.8 overnight , my 6v batts are up to baseline SG next day, and I don't need to do the 15.7 volt thing with my Vector to get them there like I have been doing.

Very interesting, but late in the day for me to learn that! (The 6s are five years old now and at 90% original capacity by actual measurement recently) :)

I also could use my external pot knob adjustable voltage PM3-100 unit to do it all, but I don't need to with my trailer set-up as is.

I am having trouble deciding what to install in the slide in camper and what to keep in the trailer among all my toys! My "Profile" needs an update someday :)

Hi BFL13,

And what brand name is that converter?

BFL13 wrote:
My 100 amp converter/charger will run at constant 103 amps for at least an hour with no tapering of the amps.

My 100 amp converter/charger will run at constant 103 amps for at least an hour with no tapering of the amps. I don't know if there is a limit to how long it can put out the 100 amps because the batteries reach the absorption stage by then and amps then taper. If I had a bigger battery bank then I would expect the constant 100 amps to continue longer than that one hour I have seen.

A factory test of a similar 100 amp converter acting in "power supply mode" to an "artificial load" had it running at 102 amps for four hours no problem before they stopped the test.

I don't know why there would be any time limit on the converter acting as a power supply at its rated output as long as it is getting proper cooling from its fan.

EDIT: a closer look at that test sheet shows that the translation into English calls it the "burning test" and they gave themselves a 2 hour spec. they ran it for 4 hours and called it a success. So Mr Wizard could be right in general as to what can be expected from a converter, but it should take some hours at full output.

ISTR Mr Wizard some time ago, mentioned he was having an issue with the small compartment that was the only place he could mount his converter, and he was concerned about it over-heating? (Maybe I have that wrong.)

But in that situation you can't use a normal charge converter, that how I cooked a wfco ( I plugged in an electric heater into the bedroom outlet on the pvr1250 )
Did not hurt the trip lite, but cooked the 100amp wfco

Converter chargers are not meant/designed to run full load constant mode (whether it is 15min or 45, therload always tapers when charging batteries)
On heavy double conversion the load doesn't tapper
For that to work without failure, the ac to DC conversion
You need a power supply some thing designed to carry a rated load continuously with out over heating and enough cooling space air flow

In my case both components where in the same compartment
The inverter was not damaged, the converter failed, different design considerations, the inverter was designed with commercial duty in mind
The converter was designed to feed a tapering load .. Batteries. The inverter powering the heater was constant, converter lasted about 45 minutes, I'm still using the tripplite inverter
This was not wfcos fault, when I did this back in march
This was mine, the WfCo is a converter charger not a continuos duty power supply

Hi MrWizard,

Here is what I mean.

Power source-->converter-->battery bank-->inverter-->RV shore power cord.

Lossy as the very old dickens for the converter is in this case 0.7 power factor, and the inverter might be 87%, but it does prevent overloading a 15 amp circuit. And if the inverter is big enough you can, on a temporary basis draw more than the output of the converter.

MrWizard wrote:
Don do you mean two chargers when you say double conversion?

Because most of the time when that term is used it is in refernce to an inverter trying to run a converter and no shore power

Because I am Not talking about that or ac to DC to ac

Also check out TrippLite they have psw inverters

I helped design the medical center load shedding system for WASHOE MEDICAL CENTER in Reno Nevada. To integrate it with 3 Caterpillar Kato 120 Kw generators. Load shedding has to be programmable because each circuit has a different hierarchy and the ordinal can and will change. In the case of WMC it started with the operating theaters, elevators, utilities (HVAC) and then down through (I forgot) but suffice to say a few dozen other levels. It cannot be done without software commands even though the programming would be basic.

I think I mentioned on this forum how much I fought against "SMART" generator paralleling whose system was VACUUM TUBE TYPE. Bottom line was they had a seven ton generator jump through a concrete wall and end up on 4th Street on fire (flammable engine coolant!)

The process is moniker-ed LOAD SHEDDING.

And good freaking luck finding something. 400 Hz military aircraft and combat operation centers employ load shedding but this is way the hell and gone exotic.

EDIT***EDIT***EDIT

Here is a touch of Load Shedding...

http://etap.com/load-shedding/load-shedding-software.htm

Don do you mean two chargers when you say double conversion?

Because most of the time when that term is used it is in refernce to an inverter trying to run a converter and no shore power

Because I am Not talking about that or ac to DC to ac

Also check out TrippLite they have psw inverters