you could be having a brownout due to summertime ac use in your area.
do you live in usa?
I can link a transformer for you.
what size is your circuit breaker?
20 amp
or 30 amp
I use a Norstar davr 5000 I purchased it from amazon in Jan of 2019
I reviewed it in feb 2019
it still works and is still in use.
it should be just okay for your gear.
I have a m21s. do you use whatsminer 5.0.2. to control it?
I have a thread on the whatsminer software as it is very good to monitor your gear.
my m21s is pretty power hungry.
https://www.amazon.com/gp/product/B07169Z3XX?my review is there:
Philipma1957
"So I got this on Friday it is Sunday so 48 hours of testing so far. Plug two prong with and adapter for a USA two prong.
Inside is a large toroidal transformer. (Donut shape). My house is in USA AND I HAVE 240 volt lines installed. They can run as high as 243 - 245 volts. So I use this to keep unit at 220 volts. So I am doing 243 to 220 conversion. I will be using 1675 watts on this 24/7/365. I got the 5000 watt unit do to a large constant load.
In the manual the unit has a 22.7 amp rating for continous use. This means the circuit breaker feeding it must be 30 amps as 80% of 30 = 24amps which would mean your circuit breaker would be able to safely feed the unit 22.7 amps. Of 120 or 240 volt power.
It also means the interior wall wire needs to be 10 gauge to run 24 amps 24/7/365.
Here is my one problem with the unit and it is very important pair of safety issues. The cable supplied is a two prong with an adapter which lifts the ground. That is first safety issue. Second safety issue is the cable is 14 gauge not good enough to allow 22.7 amps continuously . I estimate that you should stay under 13amps maybe even 11 amps to be safe if you run it non-stop.
That would be 11 x 110 = 1210 watts if you are feeding 110 volts
Or 11 x 220 = 2410 watts if. You are feeding 220 volts.
On the good side. When I run my gear on this I use 1665 watts on my kill a watt meter. When I bypass this I use 1647 watts on my kill a watt meter. So this is 99%. Efficient or it costs only 1 % extra in power to,run it. My advice is don’t overload it due to a less then specked power cable. I will do more testing but I am sure that the 5000va model will be fine at 1675 watts."
that is my review from amazon.
I am running an s17pro with it since last year it is still working, but it is on a 30 amp circuit that feeds 228 volts most of the time
It does drop to 190 volts once in a while and the 2600 watt draw from the s17 pro still works okay