Understanding RV Power
This page is here mainly for those planning to travel to Mexico, in caravans or on your own, but it is useful for the US & Canada as well.
I have been RVing in Mexico for 15 years and I have seen more than a few people with blown convertors, fridge boards, Satellite receivers, etc. Mexico generally has bad power in many areas. Low voltage, high voltage, you name it. That is not to say you are OK in the US and Canada. The same conditions can occur there, just not as frequently. There are more than a few RV parks with overloaded wiring, and wiring that is not up to snuff. Add the risk of brown-outs, and an American RV park can be hazardous to your rig as well. Do not get too tied up over this. Most people find it hard to get a handle on, unless you are an electrician. Feel free to discuss it with me by phone (604-852-1342 May-Oct). I don't care if you are a customer or not, I hate to see people stranded in a rig with a fried electrical system.
1) Electricity in Mexico is not reliable and also sometimes in the US and Canada
2) Voltages often range outside the acceptable values especially in Mexico
3) Low voltage is worse than high voltage
4) Appliances are rated at a certain wattage.
The formula is Watts = Voltage x Current (amps)
If the voltage is too low, the appliance draws more current to compensate. Current, in a roundabout way, translates into heat, and the appliance can burn out
5) In Mexico, a 15 watt outlet in Mexico may be coming off a 30 Amp breaker or no breaker. Hence if you try running stuff like A/C's, water heaters at the same time, your cord can overheat and burn, so can the outlet it is plugged into. A fused extension cord is not a bad idea if you can find one. It is a good idea to go out and feel your cords & plugs while running something with a high demand like an A/C, and make sure they are not getting hot. Other than that, just be careful not to run more than one high current appliance at a time. Do not stuff adapters (15 to 30, for eg) into a compartment in your rig, hang it outside. If it overheats, any fire is outside the rig. I have seen a rig burn where somebody has stuffed an adapter into the storage compartment. In the US and Canada, RV park wiring is more likely to be up to code.
So let's go over the 3 main types of protection.
These usually cost less than $100 and unless you happen to be in an area where the power supply is struck by lightening, they are in effect - well useless.
EMS Surge Protectors - Power Protectors:
For most people this is what you need, but you may find you end up with no power in some areas. They come in 30 and 50 amp flavors and run between $250 and $450. They are made principally by 3 companies: Surge Guard, Progressive Industries and Camco
You can find them in Portable (Steal-able) and built in versions. For the built-in you need to have some electrical know- how. For the portable, you need to find a way to make it less steal-able.
These will protect against a sudden surges like a lightning strike, but it may destroy them in the process, so putting cheap surge protector in front of them is not a bad idea. What they primarily do is block voltages outside of a safe range (High or Low) from entering your RV and doing damage. Get one that auto-resets if possible. It can take a couple of minutes for them to operate (or reset) as they check the voltages and wiring. They also protect against a miswired pedestal or the lack of a ground.
Please note that some newer RV's come pre-equiped with these. The higher end the unit, the more likely this is. However, this can be a problem in Mexico, as voltage a bit too high or a bit too low, but not dangerous, will still be blocked, meaning you have no power. In cases like this a regulator may be your best solution. Or both is actually better.
Here are some Amazon links to the 3 brands:
Hughes autoformer also makes one (Not to be confused with the actual Hughes Autoformer Voltage reglator)
A Voltage Regulator will actually modify the voltage to a correct level. In the US, this is usually the Hughes Autoformer. Don't waste your money, it is expensive. While it will raise low voltage up to 10%, it will not lower high voltage. In the US or Canada low voltage is the most likely issue, due to brownouts and an excess number of campers trying to run Air Conditioners. In that case the Hughes is OK. Low voltage is the most hazardous to your appliances as they will try to compensate by drawing more current. That can burn them out. Some RV parks ban these, but that is unlikely in Mexico. However in Mexico, high voltage is also an issue and the Hughes is useless for that..
The Cadillac of Voltage Regulators is the ISB Sola Basic, which is made and sold in Mexico. The weight of it screams quality, and unlike the 10% correction of the Hughes, it will correct up to 20% either low or high voltage. RV safe voltage is considered between 103 & 132 volts. The ISB will correct 85 to 147 Volts. Above 147 volts it will still correct, but to a bit higher than the safe range. It costs about $250 US and requires some electrical know how to wire it up. I have linked instructions below.
Home Depot in Mexico also sells a small 15 Amp regulator for about $80 that is ideal for a Class B with a small A/C. It cannot handle a standard 13.5 A/C, but will run a microwave. It comes in a Red & White Box. There are other similar models that cost a bit more. There are usually logos on the box that indicate what they are meant to power. Pick one that shows appliances. They are invariably made for15 Amp. They may well allow you to use your air conditioner, but don't try running a microwave or coffee maker at the same time.
If you want to use all 3, you hook them up in this order:
Power Pedestal - Surge protector - Regulator - EMS Power Protector - RV.
So if can get a hold of a USB Sola, you will need to butcher a 30 amp extension cord. You can carry the unit in a Milk crate, (you need 12 inch by 12 inch internal dimension). You can simply shove it under your rig to protect from dew & rain and throw it in the door for transit. There are 3 wires minimum to connect, the feed - male plug end (black) and the power out (also black) from the female socket end. You tie the 2 whites to the common (You will need a murette - see red one in photo below - to tie them together then take a 3rd short piece to the connector. The green, which is ground, you don't have to cut. You can just let it flow through, although it is a good idea to wire it to the case when you get home.
These come in 4 or 8 KV versions, 4 KV is sufficient for most RV's. The 8 KV is larger but it is not wired so it can handle an RV 50 Amp service, which is actually two 30 amps split between different zones in an RV. You are wasting your money with the 8000, buy the 4000 and use an adapter if your service is 30 or 50 Amp. 50 Amp hookups in Mexico are rare anyways. http://www.isbmex.com. You will have to bring your own 30 amp extension, you can not find them easily in Mexico. You can lock this unit using 2 locks and a cable. We will try to source these out at a spot close to the start of the caravan. Detailed instructions on wiring these may be found at https://www.mexicocaravans.com/Regulator.pdf .
You need to bring adapters to change 30 amp to 15 amp and vice versa. These are cheap and found in RV stores. We suggest you buy 2 of each. There are times when you may not be able to reach the pedestal. You may have to reduce a 30 amp pedestal plug to 15 amp, so you can use an extension cord then convert it back to 30 amp. Not all pedestals have 30 amp sockets, many are 15. If your plug is 50 amp, you will need an adapter. Bring a 25 ft extension cord, either a 30 amp or heavy duty outdoor 15 amp. There are only 3 parks in Mexico I know of with 50 amp sockets. One of them is Tres Amigos in Mazatlan, a stop on many caravans, so a 50 amp to 30 amp converter cord is a good idea. (15 amp is available there)