Inverter gremlins... what's your experience?

[TexasBorderDude]

Well I have a Trace U2512SB that started to do some wierd stuff this morning.  Had bathroom lights surge bright and dim, the TV/computer monitor would shut off.  I looked at the inverter panel and had shore power, but 12.2 12 volt power.  Charge rate was Zero and source peak voltage was 117-120 at the inverter panel.  I shut everything down, reset the breaker and powered back up.  Turned on the inverter and set to equalize.  All seems ok now.  Voltage on the house batt is back above 14 with a 25 amp charge rate.  Source peak voltage is 165-170 (which is normal for my system... although I don't understand why it's so high.)

Anyone have any similar symptoms?  Is this my 12 year old inverter just showing signs of age?

[bevans6]

Well, the peak to peak voltage of a 120 VAC RMS (typical house voltage, in other words), is 120 * 1.41 * 2 = 340(ish), so the peak voltage is going to be half that, or 170 volts.  We call it 120 volts because that is the RMS value (root of the mean of the squares of the sine wave, or .707 times the peak voltage) which is the DC equivalent of the AC waveform.  Aside - cheaper AC voltmeters read in pure sine wave RMS, so if you test your house voltage you will get a reading of 120 VAC instead of 170 or 340.  Expensive "true RMS" voltmeters measure the actual waveform presented and calculate the actual RMS voltage of the waveform, which doesn't have to be a sine wave.  That is why measuring the output of a MSW inverter can present some funky readings with normal voltmeters.

It sounds like your inverter needed a power-off restart.  I suspect that could have been due to some glitch or brown-out on the input from your AC source, or some more nefarious problem.  You're just going to have to watch it for a while.

Brian

[luvrbus]

It started when he got a short in his main cable plug he could feel the current (shock) on his bus but I never could it was strange

[TexasBorderDude]

Thanks, Brian... that explains a lot!

Well all seems normal, but in about an hour it went from equalize to float with no charging amps and batt volts at 13.06.  Will practice "watchful waiting"

[chessie4905]

   You may have not felt the shock because you have dry hands or dry skin. People with normally moist skin on their hands can feel current leakage easier.

[TexasBorderDude]

Okay, so here's the latest... I have a cheap Honeywell fan that won't run on my MSW inverter power (well not at full speed).  I plugged it it and sure enough it bogged down.  I checked the voltage at the outlet and it was between 90 and 100 volts (standard volt meter)  The battery bank was discharging and was as if there was no shore power hooked up (although it was).  I shut everything down and "re-booted" and things seem normal again.  123 Volts with same outlet and same meter.  This is normal for regular shore power mode.

Could it be that I'm getting a voltage drop at the electric service, or it more likely that the inverter is starting to act up?  Thanks.

[belfert]

Many inverters will have a shore power voltage cutoff.  If the shore power drops below the threshold the inverter will cut off shore power and start providing power from battery.

[TexasBorderDude]

Thanks again, guess I'll just watch and it repeats hopefully I can get a voltage reading at the meter.