58 replies to this topic

[Roll Me Away]

I've a class C RV and have a SurgeGuard 30 amp surge protector, however, recently experienced problems that the techs said came from low voltage. They replaced the "relay box" ... sorry, but I am totally learning about this electrical volts and surges, although someone kindly explained a few things on the forum. I'm trying to figure out if there is anything I can get and put in my coach or hook up to my coach that will prevent low voltage. The SurgeGuard and my breakers will hopefully stop anything surging. The RV parks, even the really nice ones, have drops and "brown outs" when the big 50 amp coaches come in, but there should be something to protect us 30 ampers. I have found a little volt meter that reads 120 before anything is turned on, and if the a/c is on goes to 110 and I don't turn anything else on just in case it would drain and drop too low...but what's too low? Below 110? Below 100? The little meter's needle goes from 120 to 110, and with a/c on med to high, swings a couple blips below 110 and sort of levels out. Not sure if that's good or bad, but this is full 30 amp park so the voltage perhaps is the only thing to worry about. I may get a digital volt meter to get a bit more accuracy. It's fascinating to see how much a small coffee pot takes and I'm nervous to use the microwave and hot water heater even separately on electric at some parks. Fortunately there's the propane for both, and I'm using that more.
Any input on voltage drop and how I might better prevent it is welcome. Thank you!
Roll Me Away

[Dennis M]

What you need is an EMS like this one from Progressive Industries or something similar.

It will protect you from high or low voltage, open grounds, etc.

[Roll Me Away]

Thanks, Dennis. I called Progressive and am getting the portable which does the same thing as the hardwired one voltage-wise. LIfetime warranty on it, so at least now I will have a way to protect my coach and wallet. Thanks again.

[Mark & Dale Bruss]

First off, the problem with low voltage usually comes from the park wiring.

And don't blame the 50 amp motorhomes. Quite often whenever we ran into low voltage it was on a 30 amp service.

One of the things that can cause intermittent low voltage is a bad neutral circuit. It is more obvious on a 50 amp service because you will see one leg drop and the other leg rises. With 30 amp services, it is common for two adjacent sites to be like a 50 amp service, not in amperage but in the fact that with a poor neutral, one site will drop while the other will rise.

What happens is that the current draw of devices like an AC unit will drag the neutral toward the leg with the current draw. That is indicated by a lower voltage reading. In the meantime, the other leg is farter away from the neutral electrically with a higher voltage reading.

A analog voltmeter is fine for this checking, in fact may even be better because you can see the needle swing as voltage changes.

This problem is one of the best for proving the need of an EMS. People who only meter power pole receptacles before plugging in will never see this condition as it exists only with a load. The EMS monitors conditions all the time, far safer.

Edited by Mark & Dale Bruss, 13 April 2012 - 02:20 PM.

[AFChap]

How much is too much/too little? ...I believe general agreement is 10% over/understandard 120v ...also believe that is what most systems with over/under voltage protection trips at ... ie 132v and 107v.

I use a digital line meter along with my SurgeGuard (model whch DOES have over/under voltage protection ...yours doesn't??) and am normally aware when we are on a troublesome circuit before the SurgeGuard trips.

Edited by AFChap, 13 April 2012 - 11:23 AM.

[Rif]

Roll Me Away,

The EMS you have ordered will work well to prevent power from reaching your rig when the voltage is low or high, as well as protect you from other situations like incorrectly wired or grounded power poles. It also offers protection from power surges or spikes. What it does in all situations is to stop the power from entering your rig. That may be fine in situations where the power is temporarily low, but it will quickly become frustrating when the power is constantly or frequently low, a condition seen often in older parks. When you need it the most, like during the summer when you want to run your air conditioner, the EMS will prevent you from doing so.

So, what do you do? Your choices include moving to another park, not using electricity, or turning off the EMS an letting the low voltage into your rig which will potentially cause damage to your appliances. None are good choices. There is an alternative however. You could purchase and use an Autoformer. These are devices that increase the voltage when needed. They monitor line voltage and automatically increase the voltage by about 10 percent when the voltage gets too low. They also provide some surge and spike protection. They do not provide protection from high voltage or mis-wired power poles, but they do provide a means of fixing the low voltage issue if that is the only problem.

I have and use both a Progressive EMS and a Hughes Autoformer when needed. Mine are both 50 amp models because that's what my rig is. However, I find most electrical problems when using 30 amp service. My 50 amp models work fine for either 30 or 50 amp service with the appropriate adapters. If you only have a 30 amp rig you would only need the 30 amp models of each.

I always use the EMS when I first plug into the power pole. It will check for everything, and as long as the power is OK, that is all I use. However, if I subsequently encounter a low voltage situation, which often does not occur until hours or days later, I will install the Autoformer. Since I have already satisfied myself that things are fine except for the low voltage, and since the Autoformer will also provide me with spike and surge protection while boosting the voltage, I turn off the EMS. While I would prefer to leave both on, the EMS is much faster reacting than the Autoformer, and shuts off the power before the Autoformer can boost the voltage. The time delay is milliseconds and does not last long enough to harm my appliances, but it will be very disruptive as it cuts off the power temporarily. Shutting off the EMS in this situation prevents this from happening.

I am a strong proponent of EMS systems, and they work well to prevent damage to my rig and appliances. But I have also become a fan of Autoformers since they allow me to actually do something about the common issue of low voltage.

[Kirk]

surge protectors

I've a class C RV and have a SurgeGuard 30 amp surge protector, however, recently experienced problems that the techs said came from low voltage.

What product do you have from Surge Guard? Is it this 34730, which will protect you and your RV from low or high voltages by simply turning off all power until it recovers, or do you have one of the less expensive surge protectors which do nothing more that stop large power surges? While both items come from TRC and sell under the brand name Surge Guard, they are very different things and have completely different characteristics.

Whether you get a line protection device from Surge Guard or one from Progressive, either one will protect your equipment from too high or too low of power line voltages as well as a host of other things, but neither of them will solve the problem, they simply turn off the power when it sags too low for safety or if it should rise too high. If you want something that will allow you to continue to operate your electrical loads safely, even when the park power voltage sags to dangerous levels, then what you need to get is an Autoformer by Hughes. This product will in fact boost poor voltage to where you can safely continue to use your air conditioner and other electrical equipment. It has somewhat less monitoring capability than either of the other two, but it probably is what you need where you are, unless you are willing to move.

Electrical power requirements are not a simple thing and to really understand the problems takes more than a little electrical training, but you can protect yourself and your equipment without a great deal of difficulty, but not cheaply. Based upon your note that you have ordered the Progressive EMS it is important that you realize that it will not boost your power line voltage at all, but simply removes power when the voltage sags to dangerous levels. If this happens a great deal you will probably not be very happy as you will be without any electrical power for as long as that voltage stays below 108V. What you ordered is protection, but not a power boost.

[Walkerl]

I always use the EMS when I first plug into the power pole. It will check for everything, and as long as the power is OK, that is all I use. However, if I subsequently encounter a low voltage situation, which often does not occur until hours or days later, I will install the Autoformer. Since I have already satisfied myself that things are fine except for the low voltage, and since the Autoformer will also provide me with spike and surge protection while boosting the voltage, I turn off the EMS. While I would prefer to leave both on, the EMS is much faster reacting than the Autoformer, and shuts off the power before the Autoformer can boost the voltage. The time delay is milliseconds and does not last long enough to harm my appliances, but it will be very disruptive as it cuts off the power temporarily. Shutting off the EMS in this situation prevents this from happening.

I am a strong proponent of EMS systems, and they work well to prevent damage to my rig and appliances. But I have also become a fan of Autoformers since they allow me to actually do something about the common issue of low voltage.

Rif,

We put our Autoformer upstream from the EMS so it boosts the power before the EMS. We leave both online and they work well together. Our EMS has never tripped for low voltage with the Autoformer inline.

Walkerl

[Rif]

Rif,

We put our Autoformer upstream from the EMS so it boosts the power before the EMS. We leave both online and they work well together. Our EMS has never tripped for low voltage with the Autoformer inline.

Walkerl

Mine is always installed the same way. If the incoming power is always low, the Autoformer will continuously boost it and everything is fine. I can leave the EMS on and it won't trip. However, in my situation the power was acceptable most of the time so the Autoformer was in standby non-boosting mode. When a heavy load like an air conditioner was turned on, that would cause the voltage to dip and trip the EMS a few milliseconds before the Autoformer could boost it. Of course, that removed the load and the Autoformer immediately went back to standby mode. When the EMS cycled and let power back into the rig again, all was well until a big load hit again. Then the cycle would repeat. I'm sure there are multiple factors involved, and I always try it without turning off the EMS first. Often it works, but sometimes I have to disable it when conditions are just right.

[whj]

You are getting the best advice there is, pay attention to Kirk as he is very knowledgeble. Expect to pay lots, the one I just got was $380 for the fifty amp. Hard wired ones are much less>

[richfaa]

rif said " I have and use both a Progressive EMS and a Hughes Autoformer when needed. Mine are both 50 amp models because that's what my rig is. However, I find most electrical problems when using 30 amp service. My 50 amp models work fine for either 30 or 50 amp service with the appropriate adapters. If you only have a 30 amp rig you would only need the 30 amp models of each. "

We also have both.With upgrades in park power we find less and less use for the autoformer but do use it when we are in a older campground and there are still plenty of them. The progressive EMS is always in use. We let the EMS check out the power at the pedestal before we plug in the RV and in many cases a low voltage condition may be revealed..

[Roll Me Away]

Kirk, thanks for the information(thanks to others as well). I wish I understood how the autoformer works. Does it produce more voltage? From where if voltage is low? I will definitely check it out and see if I can find a place to put it in my rather limited space (27 feet is not a lot of room in the little cubbyholes around the area of electrical input). The SurgeGuard is the big one, 30 amp, and it does have indicators of line problems, but nothing definitive. It has a delay mechanism when it shuts down and comes on again. Nothing in the packet said anything about voltage, just that it protects from surges. I called the Progressive because I've read a lot of good info on it, the forum member guided me to look into it, and the Progressive fellow called me right back and had a lot of apparently good information on it. Evidently it will block surges and also shuts off voltage over 132v and under 104v, thus hopefully saving equipment. He suggested the exterior portable as it does the same thing as the hardwired and my space is limited. The autoformer appears to be good to use with the {EMS?) if I'm reading the posts here correctly.
Thing is, in this universe of information not all of it is correct and much is in gray areas, partially correct and partially incorrect, so one has to process it, ask questions, and try to make correct choices. I have looked to members of the forum, those who are experienced and knowledgeable for advice and ideas. Maybe there's a forum where people share the electrical adequacy of the parks they've enjoyed most and safest. Anyway, I will read all posts on this subject and the autoformer and appreciate whatever I learn.
Roll Me Away

surge protectors
What product do you have from Surge Guard? Is it this 34730, which will protect you and your RV from low or high voltages by simply turning off all power until it recovers, or do you have one of the less expensive surge protectors which do nothing more that stop large power surges? While both items come from TRC and sell under the brand name Surge Guard, they are very different things and have completely different characteristics.

Whether you get a line protection device from Surge Guard or one from Progressive, either one will protect your equipment from too high or too low of power line voltages as well as a host of other things, but neither of them will solve the problem, they simply turn off the power when it sags too low for safety or if it should rise too high. If you want something that will allow you to continue to operate your electrical loads safely, even when the park power voltage sags to dangerous levels, then what you need to get is an Autoformer by Hughes. This product will in fact boost poor voltage to where you can safely continue to use your air conditioner and other electrical equipment. It has somewhat less monitoring capability than either of the other two, but it probably is what you need where you are, unless you are willing to move.

Electrical power requirements are not a simple thing and to really understand the problems takes more than a little electrical training, but you can protect yourself and your equipment without a great deal of difficulty, but not cheaply. Based upon your note that you have ordered the Progressive EMS it is important that you realize that it will not boost your power line voltage at all, but simply removes power when the voltage sags to dangerous levels. If this happens a great deal you will probably not be very happy as you will be without any electrical power for as long as that voltage stays below 108V. What you ordered is protection, but not a power boost.

[RBH]

Kirk, thanks for the information(thanks to others as well). I wish I understood how the autoformer works. Does it produce more voltage? From where if voltage is low? I will definitely check it out and see if I can find a place to put it in my rather limited space (27 feet is not a lot of room in the little cubbyholes around the area of electrical input). The SurgeGuard is the big one, 30 amp, and it does have indicators of line problems, but nothing definitive. It has a delay mechanism when it shuts down and comes on again. Nothing in the packet said anything about voltage, just that it protects from surges. I called the Progressive because I've read a lot of good info on it, the forum member guided me to look into it, and the Progressive fellow called me right back and had a lot of apparently good information on it. Evidently it will block surges and also shuts off voltage over 132v and under 104v, thus hopefully saving equipment. He suggested the exterior portable as it does the same thing as the hardwired and my space is limited. The autoformer appears to be good to use with the {EMS?) if I'm reading the posts here correctly.
Thing is, in this universe of information not all of it is correct and much is in gray areas, partially correct and partially incorrect, so one has to process it, ask questions, and try to make correct choices. I have looked to members of the forum, those who are experienced and knowledgeable for advice and ideas. Maybe there's a forum where people share the electrical adequacy of the parks they've enjoyed most and safest. Anyway, I will read all posts on this subject and the autoformer and appreciate whatever I learn.
Roll Me Away

The hardwire EMS unit is quite compact and can be installed in a very small space. It has the advantage of being theft proof.

[Stanley P. Miller]

I wish I understood how the autoformer works. Does it produce more voltage? From where if voltage is low?

The autoformer is short for automatic transformer. It increases the voltage it puts out by drawing a bit more current from the shore power and converting that into more volts for resistive loads. For motor loads it will often put the motor into a more efficient voltage range reducing the current it needs so the result is less current pulled from the shore power.

[Kirk]

I wish I understood how the autoformer works. Does it produce more voltage? From where if voltage is low?

As Stanley said, it uses a device that is called an autotransformer. Electrical power is all about the relationship between volts(which is the driving force) and amps(which is the measure of volume as gallons of water). When you multiply the two you get watts, which is the amount of work done.

A transformer changes voltage either up or down, depending upon the design. If that transformer takes 100V and boosts it up to 120V, an increase of 20%, it does so by drawing more amps of current into the primary side by an increase of current of 20%. If the output was supplying 10A at 100V without the step up from the transformer, then to boost that power to 10A at 120V the primary side will require a 20% increase, or 12A into it to send out the same 10A as before but at the higher voltage. The design of an autotransformer is such that when the input is at the same voltage that it is designed to supply, it simply passes the voltage and current through, with no effect at all, but if the voltage into it begins to sag it will send out the designed voltage, but in doing so it requires more amps to do this. One can get very technical in the explanation of what actually happens and have all kinds of very technical discussions, but in simple layman's terms, it is that simple. If you priced the Autoformer, you have probably figured out that this has a lot of design and hardware involved, but this is basically what happens.

The SurgeGuard is the big one, 30 amp, and it does have indicators of line problems, but nothing definitive. It has a delay mechanism when it shuts down and comes on again. Nothing in the packet said anything about voltage, just that it protects from surges.

If you have not yet bought the progressive, you need to check to see what model of Surge Guard you have. I have used one for 10 years and I do know that if you have the model 34730, it is a 30A model with complete line monitor capability and you do not need to buy more. If you have a model 34750 it is the same but a 50A model. Those are both portables that attach to the power pedestal, if permanently installed the model numbers would be 34520 for 30A and 34560 for the 50A version. It you have a simple surge suppressor from Surge Guard, then the model is 44740. You need to first determine what you have before you spend any more money!

I called the Progressive because I've read a lot of good info on it, the forum member guided me to look into it, and the Progressive fellow called me right back and had a lot of apparently good information on it. Evidently it will block surges and also shuts off voltage over 132v and under 104v, thus hopefully saving equipment. He suggested the exterior portable as it does the same thing as the hardwired and my space is limited. The autoformer appears to be good to use with the {EMS?) if I'm reading the posts here correctly.

Progressive is a competing company to TRC who is the parent of the Surge Guard line and they do not make some of the things that TRC does. You can get a voltage boost system from TRC which will do the same things as you get with the Autoformer.

I strongly suggest that we need to determine exactly what you have now, before you buy something else. You may spend a lot more money that is needed. If you click on the links that I have provided, each one will show you a picture of the device mentioned.

Edited by Kirk, 13 April 2012 - 06:21 PM.

[Great Horned Owl]

The autoformer is short for automatic transformer. It increases the voltage it puts out by drawing a bit more current from the shore power and converting that into more volts for resistive loads. For motor loads it will often put the motor into a more efficient voltage range reducing the current it needs so the result is less current pulled from the shore power.

Actually autoformer means self transformer. It is so named because the single winding is both primary and secondary. See an explanation here Autoformer explanation

[Kirk]

Actually autoformer means self transformer. It is so named because the single winding is both primary and secondary. See an explanation here Autoformer explanation

The name Autoformer is a registered trademark of the Hughes Corporation. The explanation you link to is for an auto-transformer, which is the main part inside of an Autoformer.

[Stanley P. Miller]

Yep, silly and confusing names.

[Roll Me Away]

Kirk, it is the 34730 that I have. However, the shut-offs increased in the late afternoon heat as the voltage evidently dropped and shut down the protector time and again and about 30 to 40 minutes later the power would come back on, although immediately when the shutdowns happened I would turn the a/c knob to OFF so it didn't hurt it when it came back on. The light on the microwave would come on when electric came back. I really should have moved when it burned up the first relay box, but had commitments to the area work-wise. The SurgeGuard worked but I think it got damaged as well. So now a new relay box is in and I'm parked where it is better, but I want to learn as much as possible to prevent this situation again. "If it ain't broke don't fix it" works fine for those willing to bleed green, but my granddad always said "an ounce of prevention is worth a pound of cure."
Now, the site's owner says he's putting in another line, a #10 to code(whatever that is) and a new 30 amp breaker box, and is quite defensive about it, I think it was because I asked for Romex, send me a bill from Lowe's. However, I've been driving to other areas and staying at other places and parks and the power troubles only happened at his site. I really need to get out of there and into a better situation. I've been on horse farms, fine ones, where the electric is 30 am or over and the lines are good and wired to handle the huge setups they have for their own coaches and units. Never happened there or any other park. Not saying it couldn't or wouldn't, but I keep notes. <G>
In light of the fact that perhaps the TRC Surgeguard got damaged in this little donnybrook, the new Progressive may be in order. I bought the SurgeGuard from Camping World and my President's Club membership was up in March, so they probably won't honor anything even if I could find the sales ticket.
The most positive thing coming out of this is the help and information from forum members. I have a better idea of what is happening and how to prevent problems. Thanks for the input. Oh, and I have a little volt meter plugged into the galley socket so I watch that little needle go to 110v under a/c full load and 120v when a/c is only on Fan. Felt the metal boxes and they are not hot nor is the line coming in. I'm horse sitting at a good place.
Roll Me Away

As Stanley said, it uses a device that is called an autotransformer. Electrical power is all about the relationship between volts(which is the driving force) and amps(which is the measure of volume as gallons of water). When you multiply the two you get watts, which is the amount of work done.

A transformer changes voltage either up or down, depending upon the design. If that transformer takes 100V and boosts it up to 120V, an increase of 20%, it does so by drawing more amps of current into the primary side by an increase of current of 20%. If the output was supplying 10A at 100V without the step up from the transformer, then to boost that power to 10A at 120V the primary side will require a 20% increase, or 12A into it to send out the same 10A as before but at the higher voltage. The design of an autotransformer is such that when the input is at the same voltage that it is designed to supply, it simply passes the voltage and current through, with no effect at all, but if the voltage into it begins to sag it will send out the designed voltage, but in doing so it requires more amps to do this. One can get very technical in the explanation of what actually happens and have all kinds of very technical discussions, but in simple layman's terms, it is that simple. If you priced the Autoformer, you have probably figured out that this has a lot of design and hardware involved, but this is basically what happens.
If you have not yet bought the progressive, you need to check to see what model of Surge Guard you have. I have used one for 10 years and I do know that if you have the model 34730, it is a 30A model with complete line monitor capability and you do not need to buy more. If you have a model 34750 it is the same but a 50A model. Those are both portables that attach to the power pedestal, if permanently installed the model numbers would be 34520 for 30A and 34560 for the 50A version. It you have a simple surge suppressor from Surge Guard, then the model is 44740. You need to first determine what you have before you spend any more money!
Progressive is a competing company to TRC who is the parent of the Surge Guard line and they do not make some of the things that TRC does. You can get a voltage boost system from TRC which will do the same things as you get with the Autoformer.

I strongly suggest that we need to determine exactly what you have now, before you buy something else. You may spend a lot more money that is needed. If you click on the links that I have provided, each one will show you a picture of the device mentioned.

Edited by Roll Me Away, 14 April 2012 - 06:55 AM.

[Roll Me Away]

Mark and Dale, I'm not blaming the 50 amp coaches only relaying what several park owners told me, probably erroneously. As I can find surgeguards and that sort of equipment, somehow a good "sh*t detector" has eluded me. And that was in good humor, not sarcasm. I have to sift through like anyone else except the experts. Personally, I think it is old wiring or damaged wiring, or something to do with delivery of the electrical current which includes I'm sure the neutral and ground faults and all the other stuff I'm learning about. Thank you for the information, for the other factors to research and adding to my knowledge of this.
Happy travels.
Roll Me Away

First off, the problem with low voltage usually comes from the park wiring.

And don't blame the 50 amp motorhomes. Quite often whenever we ran into low voltage it was on a 30 amp service.

One of the things that can cause intermittent low voltage is a bad neutral circuit. It is more obvious on a 50 amp service because you will see one leg drop and the other leg rises. With 30 amp services, it is common for two adjacent sites to be like a 50 amp service, not in amperage but in the fact that with a poor neutral, one site will drop while the other will rise.

What happens is that the current draw of devices like an AC unit will drag the neutral toward the leg with the current draw. That is indicated by a lower voltage reading. In the meantime, the other leg is farter away from the neutral electrically with a higher voltage reading.

A analog voltmeter is fine for this checking, in fact may even be better because you can see the needle swing as voltage changes.

This problem is one of the best for proving the need of an EMS. People who only meter power pole receptacles before plugging in will never see this condition as it exists only with a load. The EMS monitors conditions all the time, far safer.