How to reduce a WZRELB /RELIABLE PURE sinewave inverter output voltage?

[fabieville]

I have a WZRELB brand 24v 3000watt pure sinewave inverter. I notice the inverter at idle  it is producing about 114vac but as soon as u applied load it pumps up the output to around 135vac sometimes it reaches even 141vac which cause my fridge guard to chip to protect the fridge from high ⚡ I see 2 preset blue resistors inside but I am unsure as to which one to adjust to reduce the output voltage. Could you take a look at the photo and tell.me.if u figure out which one? They are rite beside the inductor on the rite side of the photo. The blue one exactly above the inductor is the closest one to the inverter output so I am assuming it's that one. Please tell me which one or what else i can do to reduce the output voltage.T hanks in advance.

[joestue]

so there's a possibility you have multiple parallel smps transformers feeding 200 volts to the pwm h bridge... and not all of those transformers are delivering the same voltage.

at idle, some are shut down to conserve energy, as they have a minimum switching loss continuously while running.

I would measure the voltage on the high voltage dc side and see if it is changing during operation. if not.. and this is likely the case, then the output is a failure of the voltage regulator to generate the pwm waveform.

reducing the voltage by changing the circuitry may cause the voltage at idle to drop to the 100 volt range which is not what you want, but may be forced to accept if you cant find the source of the problem.

[fabieville]

reducing the voltage by changing the circuitry may cause the voltage at idle to drop to the 100 volt range which is not what you want, but may be forced to accept if you cant find the source of the problem.

with this mind which one of the preset resistors should i adjust?

[joestue]

One is probably a current limit the other a voltage sensor.

Looks like 10 turn pots.

[fabieville]

which one is the voltage sensor?

[Mary B]

which one is the voltage sensor?

No way to tell with a no name inverter like that...

[noneyabussiness]

from a quick glance, it looks like a eg8010 based output, they do have a adjustment on the output , 200 kohm with a 10kohm buffer if it follows the datasheet example...  google it, lots of documentation..

Personally , I'm think extra noise is creeping into the feedback loop causing it to increase the output voltage, these chips are pretty rock solid when used correctly.. ether on the boost converters ( by pic, 4 in series) as stated earlier or in the actual " ac output" ... but without a significant amount of extra data, its all guesses ...

[Bossrox]

Have you tried contacting the company?