Author Topic: BONDING TWO INVERTERS AT NEUTRAL  (Read 9721 times)

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OperaHouse

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Re: BONDING TWO INVERTERS AT NEUTRAL
« Reply #27 on: April 24, 2017, 01:35:41 PM »
A good test for any FETs is to check the two outside pins of the FET for resistance.  Most often the gate will short.  For the boost converter, place an incandescent lamp for the appropriate supply voltage in series with the power.  The FET are usually connected to power all the time and you can easily determine which boost inverters have failed.  There may be seven or so transformers.   If the lamp doesn't light, The driver transistors for the FET gates may have failed.  The HV sections are usually in parallel, but I have one where each one adds 35V in series.  That 95V may be the case.  The output H bridge FET can be tested for shorts with an ohm meter and it sounds like you already did that.

jack11

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Re: BONDING TWO INVERTERS AT NEUTRAL
« Reply #28 on: April 25, 2017, 11:13:17 AM »
Thank you, I'll run these tests to see what happens.

The other option I thought of (for this PowerBright inverter and for others that fail in similar ways) would be to trash the DC-DC section entirely, feed the high voltage DC generated elsewhere directly into the link capacitor, and let the H-bridge work on it. But in doing this I'd need to make sure to retain the power supply to the H-bridge control section which now works off the 24Vdc input.

Sounds like a lot of work for a defective piece of crap, but this inverter generates the final AC waveform with harmonics that happen to be just right for a project I have.