A heads up on power

I have never seen the power monitor in the motor home read less than 116 or more than 120. usually 118 . steady, no up,no down. A friend of mine watched for a season. bought one this year. one week later more than 7 RV's lost micro waves, refrigerators boards of all descriptions etc. My friend did not lose anything. his unit placed in front of his surge protector stopped the spike, reset and went on working. His power stays at 114 for some reason. When measured the power here is usually 129 and higher, tripping surge protectors daily.

A couple of things here. Voltage seen on meters or monitors from one rig to another can vary depending on any number of reasons.
First - it is is different device and they can vary - I can use two different meters plugged into the same outlet and see different numbers. Good professional multi-meters probably won't do this.

There can also be variations from an analog meter to a digital meter. I can put an analog and digital next to each other and see different numbers.

Depending on where the meter is and what circuit it comes through could cause different readings. In our rig all our outlets come through our inverter. It is a modified sine wave - not a pure sine wave - this will cause a digital meter to read differently - on the same exact circuit an analog might read 120 while a digital might read 108. There are electrical/electronic reasons why a modified sine wave and pure sine wave will be seen differently on some meters - usually digital. There could a be other reasons for seeing different readings from one rig to another - even from one pedestal to another.

A surge protector should always be used because you never know when some weird juice is going to come down the line and fry some of your equipment. I have had lightning strikes near a stick house blow out all my TV equipment. A surge protector is cheaper than a new TV or stereo or fridge. All of these things have sensitive electronic components and the right zap will kill them. A surge protector is a line of defense that can save your equipment. Nothing but a surge protector will protect from a real spike.

I have tried to point out a number of times on this forum that there are many RV parks in Mexico that are not properly wired. They do not wire to code. There are mathematical formulas for wire size and distance wire can go before larger gauge is required. There are incoming circuit factors - size of transformer - size of wire from transformer to circuit panel - breaker size - number of outlets on a circuit - the list goes on and is long. If the RV park circuits are not adequate there can be lots of variations seen with incoming voltage to a rig. When a neighbor turns on or off their air conditioner for example you could see serious changes in voltage from high to low - but you would have to be watching the meter for that couple of seconds when the power fluctuates due to changes in requirements somewhere in that circuit.

We were recently in an RV park that had never had a large caravan before. Lots of big rigs. There were already quite a few other rigs in the RV park. The demand on the power supply caused first the meter box to catch on fire. That was repaired. A day or so later the main breaker burned up - to be replaced by a larger breaker. Now the wires going from the main out to the park are at risk as the larger breaker is not going to trip when demand goes up and this could mean the wire is the weakest link and is going to burn. These older parks - and even some newer parks - were not built to meet the demands of today's big rigs.

You may be lucky and be in a park that is properly wired - there aren't many of them. In the US inspections are required to check for proper wiring. In Mexico - not so much. Much of the wiring we see is not even done by electricians. The problems for those of us who RV to travel can be endless. Those who stay in one place all season may not see the same problems. But as we wander all over Mexico we see variations in problems and causes too numerous to mention. We always check for proper polarity and for proper ground. We use our voltage regulator and surge guard no matter where we go. I always test circuits before I hook up. Our experiences of having to replace expensive electronic components has taught us you can't be too careful.