Xantrex sw5548 staking issues

vprinc

Hello all.  I have an issue that I thought someone might have encountered. I was having issues with my washing machine not latching.  In process of troubleshooting I tested frequency.  At the inverters I was getting 180Hz off of one and then the second inverter was all over the place (anywhere from 300 - 390 Hz). 

So I went back to the manual and reviewed my installation to make sure I didn’t mess something up. 

My understanding is that besides using the swi cable between the inverters the only other thing I need to do is have a common neutral between the inverters double the size because all 3 neutrals are jumped with the metal clip.  

My question is am I reading the install manual correctly or am I missing something?   Can’t figure out why the frequency is so out of wack.  

BB.

Are you "stacking" two inverters to provide 120/240 VAC split phase power (need stacking cable???).

Or are you trying to Parallel" two inverters to provide more current at 120 VAC (I don't think that these support parallel 120 VAC operation)?

(Note: I am not very familiar with these inverters--So the above was based just on a quick look the manual).

I would double check your frequency meter and installation in general. Are you getting your 120 (or 120/240 VAC) running voltages? Are you getting 60 Hz with your meter just measuring Grid voltage (your utility voltage for home, backup Genset, etc.)? Double check that your meter has a "good set of batteries"....

These should be (as I understand) a "sine wave" type inverter, and your meter should easily read the 60 Hz +/- a couple of Hz...

No way should you see 180-300+ Hz in normal operation.

You may need an Oscilloscope to see what waveform(s) you are actually generating from these inverters...

Be careful using a generic O'scope... Most of the one intended for electronics labs have a "grounded" lead and placing the scope and ground lead on the "wrong" power lead can create a dead short and let out all sorts of magic smoke.

I know nothing about the meters in this Amazon Link:

https://www.amazon.com/s?k=portable+oscilloscope+multimeter

But for a $100 or less, one of these "multi-meter" O'scopes might be real handy to have to debug your installation.

-Bill

vprinc

BB. 
Thank you for responding.  So we are off grid so no grid power at all into the inverters.  We are series stacking to provide 120/240 split phase. I’m using a high end Klein handheld so need to pick up an oscilloscope. 

littleharbor2

Does your only issue appear to be the latching mechanism on your washing machine? Refrigerator running well lights everything else okay? If so I think it's monitoring error.

Dave Angelini

Also compare frequency readings with a genset for a sanity check of frequency !