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Kg4izw · 01-03-2022, 07:24 PM

I have noticed that lately when using the microwave for more than two minutes that my living room lights slowly begin to dim. Today I was curious about the amp draw so went over to the Xantrex 2000 inverter/charger display and was shocked by what I saw. I watched the battery voltage slowly drop as my food continued to cook (similar to how it does when I am unplugged and running on the inverter battery backup). Once the voltage dropped to 12.6, the charger moved from float to bulk and started recharging the battery. Once the microwave turned off, the battery voltage hopped back up to 14.4 and shortly switched back to float at 13.5.

I checked and made sure the shore power was connected and checked the input voltage, all good.

I then "disabled" the inverter and tried the microwave again. Same battery voltage drop resulted.

I then disabled the charger, and the problem went away. I cooked more food with the charger off. The battery voltage held steady.

After I was sure the voltage was not dropping and microwave still running, I turned the charger back on and immediately the battery voltage dropped and the charger went back to bulk to make up the deficit.

What is wrong here?

Can someone shed some light on this please?

Steve-W · 01-03-2022, 08:00 PM

Assuming you have a inverter/charger. Just a thought, could the internal transfer switch in the inverter not closing when on shore power. If this occurs the load would be carried by the inverter vs shore power. If that were the case the charger section of the inverter would try to replenish the batteries as the battery voltage drops due the load the inverter section is placing on them.

You should be able to see what doing what on the inverter display/remote.

**Lt Dan** · 01-03-2022, 08:19 PM

Do you have an EMS to protect against low voltage? Have you monitored the shore voltage when using the microwave? It almost sounds like your shore power voltage is dropping below the cutout point for the charger caused by the draw of the microwave, especially since you got the same result after disabling the inverter. On our Magnum charger, it will drop out if the voltage drops below 90 volts.

Marine359 · 01-03-2022, 08:51 PM

If you have a Xantrex Freedom XC2000, it has two modes: grid mode and battery mode. If you’re hooked up to shore power, or generator, you should be in grid mode. If you are running your incpverter with no shore power or generator, you should be in battery mode. When in grid mode, you should never experience what you have posted, as the Xantrex will pass-thru your ac source. If you’re not hooked up and you’re in battery mode, the Xantrex will output as much amperage as your battery can supply. It’s not a good idea to run your microwave when you are in battery mode. The Xantrex will shut down for over-amperage. I’ve been able to run my microwave on defrost, which only turns on the microwave for a few seconds, then cycles off for a few, then on for a few. That’s what your microwave is set for 50% power. Generally, it’s not good to run your microwave off the Xantrex when you are in battery mode.

Kg4izw · 01-04-2022, 12:04 AM

Quote:

Originally Posted by Kg4izw

I have noticed that lately when using the microwave for more than two minutes that my living room lights slowly begin to dim. Today I was curious about the amp draw so went over to the Xantrex 2000 inverter/charger display and was shocked by what I saw. I watched the battery voltage slowly drop as my food continued to cook (similar to how it does when I am unplugged and running on the inverter battery backup). Once the voltage dropped to 12.6, the charger moved from float to bulk and started recharging the battery. Once the microwave turned off, the battery voltage hopped back up to 14.4 and shortly switched back to float at 13.5.

I checked and made sure the shore power was connected and checked the input voltage, all good.

I then "disabled" the inverter and tried the microwave again. Same battery voltage drop resulted.

I then disabled the charger, and the problem went away. I cooked more food with the charger off. The battery voltage held steady.

After I was sure the voltage was not dropping and microwave still running, I turned the charger back on and immediately the battery voltage dropped and the charger went back to bulk to make up the deficit.

What is wrong here?

Can someone shed some light on this please?

Sorry I made a typo above.

The Xantrex model should read Xantrex 3000

more specifically SW 3000.

In following up:
I pasted page 55 of the manual below : could this be what is happening?

97-0019-01-0155
Configuring the Freedom SW using the SCP
ACIn Settings
TheACIn Settingsmenu configures the voltage and frequency
limits for AC Input quantification range. These are the limits at
which the Freedom SW considers input voltage qualified—that is,
suitable for charging batteries or powering loads. If the input
voltage is not qualified according tothese settings, the Freedom SW
transfers from using AC input to inverting

Biljol · 01-04-2022, 07:17 AM

I think your on to something there, I had a similar problem, was at a park once that the voltage would not hold when turning on an AC. The inverter saw the drop in shore volts and switched to inverting.

At least I thought it was the park latter I was connected to a good known 50amp location and had the same issue after a lot of tests ended up my connections In my ATS had come loose and that was causing the voltage drop.

I figured out the ATS issue because it also was happening on genset power.

Thing is that was with a AC seems that a microwave should not cause the volts to drop that much but you did not tell us what shore power amps your connection is but I would check all the connections from shore to the inverter—- of course after all power is disconnected and safe.

Marine359 · 01-04-2022, 12:37 PM

Quote:

Originally Posted by Lt Dan

Do you have an EMS to protect against low voltage? Have you monitored the shore voltage when using the microwave? It almost sounds like your shore power voltage is dropping below the cutout point for the charger caused by the draw of the microwave, especially since you got the same result after disabling the inverter. On our Magnum charger, it will drop out if the voltage drops below 90 volts.

Lt Dan likely correct, but if it’s not your SP voltage, call Xantrex customer service. They are pretty good about helping out.

Kg4izw · 01-04-2022, 03:59 PM

thanks everyone
I did notice that I had a tiny space heater on at the same time as I was using the microwave. Perhaps that coupled with the microwave caused the voltage to drop lower than what was coming in.

I am running 50 amps. With the microwave running, the input voltage was 122 on leg1 with 0A draw and 116 on leg2 with an amp draw of 26A.

ArtJoyce · 01-04-2022, 04:18 PM

How many batteries do you have? Batteries will drop when a load is put on them and pop back up once the load is removed.

A microwave pulling 1000 watts of power through 12v dc to 120v ac inverter in going to pull north of 80 amps from your battery bank. I would think you need a minimum of 450 amp hours of battery not to see a noticeable effect on your lights. But you still will see some voltage drop when running the appliance.