Opposite of Power Surge, a Power Wane

First thing is get a voltmeter and see what's going on inside. Also check at the pedestal to see if it's different and maybe a couple of other pedestals in the CG.

If it's a sag, dip, drop, brownout or whatever you want to call it and it gradually undulates up & down and is unrelated to your power draw, it could be the CG system (if many users in the CG) or the utility company. I wouldn't expect it to happen this time of year in a CG, unless perhaps if you are in an area where the temperature has taken a dive and maybe a lot of nearby residential users are plugging in electric heaters?

If the voltage goes down quickly in response to plugging in heavy loads like a hair dryer and the voltage stays down for the duration the heavy load is on, it's likely a voltage drop in wiring in the CG system.

If something like the light on the MW seems to flicker quickly when you turn on a heavy load, it could be a bad connection somewhere - either inside your unit or upstream in the pedestal or CG distribution system.

I would check your shore power plug and the pedestal receptacle. If they've gotten dirty and pitted, with the higher resistance when you plug in/turn on higher draw appliances, the plug and/or receptacle can't support the higher current. If it were this, you can end up with a meltdown of the plug too. Less likely but it does happen once in a while, is a problem with the CG power distribution system somewhere like a bad connection in a pedestal or distribution panel.

Cold and moisture can affect connections in a CG pedestal because breakers and panelboards (which is essentially what a pedestal is) aren't really specifically designed for low temp./high humidity locations and I would expect more problems with them this time of the year. Pedestal breakers can take a beating from all the on/off usage and the receptacles can also take a beating from plugging in while live and yanking cords out. It's possible the problem is simply a bad pedestal.

If you don't have one already, a "surge protector" like a Progressive Industries EMS is a good investment. I'd get a hardwired one with remote display. If you do happen to be in a location where voltage fluctuates a lot, an autoformer like the Franks or Hughes will help.

Surge protectors come in two (By two by two) flavors. The last 2x2 are 30/50, and hardwired/plug in and since the first is based on your RV's power plug and the 2nd is your choice,, We will leave them here)

The important two
Spike Suppressors (I have a hard wired version) Have LED's or other indicator lamps (NEON perhaps) but no LCD display, these are designed to clip the tips off high voltage spikes, the active device is an MOV (metal oxcide varisistor) which presents a high resistance to say 200 volts but at say 400 volts it becomes a near short (Normal peak voltage in a 120 volt circuit is about 180 volts (rounded seriously) 1.414 is the actual multiplier or (Sqrt(2)).

Option 2: The units WITH an LCD that displays current, voltage and possibly other information: These units monitor voltage, some monitor Frequency and other stuff, plus they have time in timers.

When you first plug these in they do NOT deliver power to the RV but a timer starts 2-3 mintues later CLUNK and power is passed on.. If the voltage drops too low CLUNK and power is cut off, If voltage goes too high (But not enough to fire the MOV's) and stays there for more than a time lmite CLUNK they cut you off. NOTE: a true surge (Sustained high voltage) will turn your MOV's into Firecrackers (Been there when that happened, was kind of impressive) But the Surge Guard or Progressive INdustries EMS units will protect you.

Plug your 30 amp rig's Surge Guard into that 30 amp outlet at your friend's house (240 volt) and it will tell you "240 volts" (plug the spike supressor in and it may well tell you BANG BANG BANG as the MOVs go off).

Something happens and the power grid re-configurs shutting you down for like 1 second causing your air conditioner compressor to hot-start and size up. NOT WITH A SURGE GUARD of the lcd type, cause when the lights blinked off that reset the time in timer, 3 minutes later the A/C starts normally. (Been there and done that a couple times where I am currently parked)

All in all I reather like the LCD unit I have. And mine is not the best (Which is Progressive Industries)

The Auto Former will help to a point. Older/larger RV Parks are usually where you see this. Worse we saw was an RV Park in Minnesota, right on the lake.
The cables or wiring were buried long ago and they get a lot of snow and freeze and thaw. The pedestals were badly corroded wiring and connections also.
The water pipes were just as bad.
Some Parks won't spend the money for adequate power. When they have a huge July Fourth every body get a brownout and many loose air conditioner motors, microwaves, and sensitive electronics. The pedestals get real hot.
Not much on Parks with these problems in reviews.
Note it and pass it along.

Ruck wrote:

To bridge over a sag like that, you need something with an autoformer built into it. Of course those are the most expensive type...

I don't have one but I'm sure someone here could recommend a good one.
CG owner said he had a problem similar to it on another site, next door, a bit ago, and the camper had a pro look at it and it was the breaker, will change it first and see what happens, thank you!
Breaker! 50amp GE, has solved the problem, so far everything is working as it should... (fingers crossed) Thank you all for the input!!

To bridge over a sag like that, you need something with an autoformer built into it. Of course those are the most expensive type...

I don't have one but I'm sure someone here could recommend a good one.
CG owner said he had a problem similar to it on another site, next door, a bit ago, and the camper had a pro look at it and it was the breaker, will change it first and see what happens, thank you!

Ruck wrote:

ScottG wrote:
That's a sag and a surge protection device like the Autoformer will protect against it. FWIW, that is as damaging as a spike in many circumstances.

Thanks, have a 'Smart Surge' protector, two lines, with white arrows indicating 'line 1 and 'line 2' with green indicator lights, 'line 2' indicator light is intermittent and 'buzzez' in and out, am thinking about getting a better protector, had one and burned it up using it with my gens one time.... Thank you again, and does that sound like a solution?

To bridge over a sag like that, you need something with an autoformer built into it. Of course those are the most expensive type...

I don't have one but I'm sure someone here could recommend a good one.

ScottG wrote:
That's a sag and a surge protection device like the Autoformer will protect against it. FWIW, that is as damaging as a spike in many circumstances.

Thanks, have a 'Smart Surge' protector, two lines, with white arrows indicating 'line 1 and 'line 2' with green indicator lights, 'line 2' indicator light is intermittent and 'buzzez' in and out, am thinking about getting a better protector, had one and burned it up using it with my gens one time.... Thank you again, and does that sound like a solution?

My guess would be power problem at pedestal/park power system

Or your inverter/charger is failing or loose connections.

Test the voltage output at the pedestal and output at your electrical outlets. If less at the electrical outlet when compared to the pedestal then I would suspect something in your RV.
If the pedestal is showing low voltage let the park staff know.

That's a sag and a surge protection device like the Autoformer will protect against it. FWIW, that is as damaging as a spike in many circumstances.

Have you monitored voltage on both sides of the panel during the dip in voltage?