Converter power draw

[Life-in-Him]

Got my Hughes PWD30-EPO installed.
Works great but monitoring useage poses a question:
The Converter is in float mode & in-Command & vom show 13.2 volts @ batteries.
That draws 3.1 amps AC 122v
When the converter stop & does what I call "take a look mode" volts drop to 12.6-12.8. AC current is 0.1 amps 122v.

Seems like 3.1 amps ac for converter input in float is a lot
Converter is wefco stock in our 2020 Cougar. 24sabwe. Don't know the converter model#.

Any ideas?

[pasayten]

I have a 2021 Cougar 26RBS... It came with a WFCO WF-9855 converter. When you say the converter is using 3.1 amps when in float mode, how are you measuring that? There are other AC loads besides the converter... Mine include the inside refer, outside refer, and tv... besides the converter. You can switch off the circuit breaker to thr converter and measure the sum of the other loads... but the refers will be cycling at times. Have you directly measured the AC draw on the converter with a clamp meter? Most AC clamp meters have an accessory to help measure corded devices.

[ChuckS]

The converter output .. if it’s still OEM WFCO should never drop under 13.2 volts in any of the three operating modes..

See theory of operation so you know what the three modes of operation are and what they are called..

https://wfcoelectronics.com/wp-conte...eration-v2.pdf

When my Alpine sits here at the house after 40 plus hours of non use with converter on the output drops to 13.2

When I measure AC current draw .. by measuring directly at the power center 50 amp breakers I rarely see more than .9 amps current draw on both L1 and L2 breaker connections on the load side

[Life-in-Him]

Interesting.
Turned off CB labeled Converter.
Total RV AC I dropped to 0.6 amps.
Turned it back on, I stayed @ 0.6a
Off/on again. I still @ 0.6a
Bat v = 13.3.

Need to verify CB labels & recheck battery V w/CB off

Earlier, had DC clamp-on Ampmeter on battery red lead. Cycled from 0.09 a to 0.54a about a min apart. Nothing going on in RV but refer.

[bsmith0404]

I’ve never measured converter draw, but had a factory rep from Keystone tell us the converter typically draws around 7 amps. That is why it has its own dedicated breaker. I also know that when I was trying to run the AC on my smaller 3300 watt gen at 7k ft altitude, I had to shut the converter down or it would trip the gen breaker. The converter draw was enough to make or break running the AC on the gen.

[JRTJH]

Remember that there are "phantom drains" on the trailer electrical system. Also the converter has an inherent drain (energy consumed within the transformer/ac/dc converstion process) within itself. So, you can/could have an amp or more being consumed by the LPG detector, CO detector, radio memory circuits, In-Command "standby circuits" and any other potential "always on systems" in the trailer.

The WFCO converter will always (if it has power on) have some energy consumption.

Also, using a "third component that has LED's and a monitor circuit within it will consume some power. So, measuring the "input power on the trailer shore power cable" is always going to be "some consumption of energy" as long as the LED lights on your EMS are illuminated. Those LED's consume power that the EMS is displaying.

[Life-in-Him]

My panel is a wc8955pec.
30 amp AC in.
55 amp DC out
What we were looking for is the net AC consumption of the basic unit
I found 1 WFCO list that showed the 8935 @ 13.6v & 860 watts max AC input or 7.2 amps 120v. They aren't 100% efficient. So figuring 80% internal loss would draw about 9a total @ 120v. Or 2 amps of xformer, heat etc loss

It's not really important.
Just looking @ solar needs etc. & Solar would charge directly. Probably need a controller that cuts out the converter so it doesn't waste those 300 watts

[JRTJH]

The specs on the WFCO converter/charger are "maximum design capability at a specific input voltage. That usually is established at 120 VAC, but I can't say for sure exactly what voltage WFCO uses. Also remember that as voltage goes down, amperage goes up to maintain the same wattage. It's the same "on the other end" with the DC output. At 13.2 VDC, the amperage will be different than it is at 13.6 VDC. and that 55 amp output is not a constant output. If the demand (lights, battery charge status, refrigerator, furnace fan, etc) are on or off will affect the demand for DC output.

Your specs: 30 amp AC in and 55 amps DC out are not correct. 30 amps@120VAC is 264.7 amps at 13.6 VDC. The reality is that AC input for the converter/charger is somewhere around 7 amps @ 120 VAC input to achieve 55 amps @ 13.6 VDC output. That's roughly 840 watts in and 748 watts out with only accounting for around 100 watts energy loss within the convertor process.

So, as an example, if the battery is "nearly discharged" and the furnace fan is on, the DC demand may be 50 amps at 13.6 VDC. That's 50x13.6=680 watts output. If the battery were "fully charged" and the converter output was 13.2 VDC, the amperage demand may be only 25 amps, so the wattage would be less than 680 because the demand was less. At 680 watts output, that would require 5.666 amps at 120 VAC input, but would require 6.182 amps at 110 VAC input (assuming a hypothetical 0 watt consumption/loss within the converter).. That's a "near impossibility" in reality, but difficult to calculate on the given consumption guesses...

As you can see, there are way too many variables to "nail down a specific amperage reading on an EMS and make the determination on power output on the WFCO converter based on EMS amperage on the LED screen,m and honestly, it's getting so far out in the weeds that we may not even be able to see the trailer because of the forest...