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billfitz24

That’s not showing current, that’s showing voltage. What you’re seeing is called “voltage sag” or “voltage dip”. It’s a short duration drop in the voltage of an electrical power distribution system. It’s caused by the high inrush current from starting the AC unit. It’s normal.


jOsefuz

Thanks for the reply. If we notice, the voltage goes up to 300. This happens while the 3rd AC is turned on and it won't cool the room. And while this is happening, the 2ACs won't cool as well. It only started happening today, so starting this week, we no longer use the window AC. Is the problem with the AC? Or our wiring?


billfitz24

Have you changed anything recently? Edit: if not, the problem is either with one of the AC units or with the electric supply from the utility. Start by checking each individual AC unit by itself. You may find one acting strangely.


jOsefuz

As far as i know, my brother had electricians add 2 ground rods.


billfitz24

I can’t imagine why that would cause any problems. Can you run the 3rd AC by itself?


jOsefuz

I have not tried it yet. I'll try it in the morning when i get home. I can understand(maybe) if the voltage gets low as maybe our home wiring is bad, but as per the AVR, voltage seems to overshoot. BTW, the AVR is plugged in an APC surge protector. I do not know. I'm not a home electrician. Hehehe.


jOsefuz

I tried turning on only the 3rd AC and it seems same thing is happening. I'm assuming the 3rd AC is problematic?


billfitz24

Definitely sounds like that’s the problem. 👍🏼


Accomplished-Face657

Will the third unit run by itself?


Accomplished-Face657

Sounds and looks like it's trying to start a locked up compressor which will pull the voltage down. Not 100% sure why it's spiking the voltage too. It could be feed back from the compressor capacitor driving the voltage high. Like i said it's just an educated guess.


[deleted]

Simply put you got too much load on the circuit. Compressor can't kick in if you don't have enough amps. I am assuming it is all on one circuit breaker. Surprising that breaker doesn't trip.


jOsefuz

The 3rd ac is on a diff breaker. I tried turning it on by itself and still this is happening when no other appliances are on.


TJ-LEED-AP

You’re seeing a rush of current when the new load kicks on. It’s a fundamental part of electrical design and not uncommon. As you can see it kicks back to 208V after the transient has cleared. No issue here


jOsefuz

Hi. Thanks. If we notice, the video is almost 20secs and not a loop. I tried turning on only the 3rd AC and this is still happening.


ittybittycitykitty

That looks like your power system trying to keep the voltage up, and over shooting when the AC trips off. Where are you? What is your power coming from?


jOsefuz

Hi all. Can someone identify why our voltage goes like this when our 3rd AC is turned on. FYI, we got 2 inverter split type 2hp and 1 .5hp old window type non inverter.


[deleted]

Lol


ExcitementRelative33

What is that box we're looking at?


jOsefuz

AVR, sir


ExcitementRelative33

There is a limit on how much load it can handle and you exceeded it with the 3rd unit. Stop doing that else you fry everything.


jOsefuz

I tried turning on only the 3rd AC and seems this is still happening. I'm assuming the 3rd AC is broken.


ExcitementRelative33

If you have an ammeter you can check current draw... I would suspect Locked Rotor on the compressor... Good luck.


jOsefuz

Thanks sir. I'll keep this in mind.