Surge protector at home

[Butch63255]

Hello all, I just installed 30 amp service at home to plug the rv into. I have the plug in surge protector for the the campgrounds. I'm sure it cant hurt, but wondering if its necessary to use it as well at home knowing I have good connections,ground etc?

[valleyduo]

Originally Posted by Butch63255

Hello all, I just installed 30 amp service at home to plug the rv into. I have the plug in surge protector for the the campgrounds. I'm sure it cant hurt, but wondering if its necessary to use it as well at home knowing I have good connections,ground etc?

It would offer protection for the more sensitive elements of your rv in the event of a power surge. My thought is, if you own it, you may as well use it. Be a shame to miss some camping time because a converter or a/c was fried when it could have been prevented.

[Tx2Stepn]

We use ours just in case we are hit by lightning, which has happened several times where we live.

[HangDiver]

A few weeks ago the power went out at our house (which is a rare event). When it came back on there was a loud "POP". A couple of surge protectors in the house were toasted along with our wifi router (which was connected to one of the surge protectors).

Even though the voltage in your home may generally be stable, the EMS will protect your RV from those unlikely events that can still happen. I would use it.

[Tx2Stepn]

I forgot to mention that the last time lightning hit our transformer the electric co fixed it with it reading 140 volts. We didn't have a camper then, but the only way we figured it out was our toaster was burning the toast. With the EMS system we know exactly what we're getting.

[wmtire]

Originally Posted by Butch63255

Hello all, I just installed 30 amp service at home to plug the rv into. I have the plug in surge protector for the the campgrounds. I'm sure it cant hurt, but wondering if its necessary to use it as well at home knowing I have good connections,ground etc?

A surge can happen at home as well as a campground. Would use it "anywhere" you are plugged in at.

[Butch63255]

Thanks all. Fiqured I pretty much already knew the answer but thought it wouldnt hurt to get a few options.

[dbledan]

You would be suprised how many people come on here after having a 30A outlet installed only to find out it was wired for 220...not that this would happen to you but the EMS would catch it as well as the surges. I always use my EMS at home and I have a whole house surge guard as well. Just my opinion but always use it. Never know and you bought it for a reason. I even use it with my generator.

[whj77372]

I have 50 AMP at home and I wouldn't think of not using a surge protector/electric management system when I plug in.

[Cowracer]

Offering a contrary opinion...

I am a 25+ year experienced Electrical Engineer (specializing in Control, automation and power distribution systems) and I'd never waste my money on anything like a "surge protector". I've never had one on anything I own (Camper, household or industrial) and never had anything damaged by a surge. The only benefit they provide is telling you when your pedestal is wired incorrectly and a cheap, $20 tester will do that.

Lets look at what these things are supposed to do for you: (taken directly from a popular brands website)

Open Ground, Open Neutral & Reverse Polarity Detection

Miss wired Pedestal Indication

Surge Failure Indicator

Thermally Protected

Weather Resistant

Rugged Pull Handle

Brighter 3-Color LED Indicator

Designed for Outdoor Use

Lifetime Warranty

The first two are easily tested by that $20 tester. Surge failure indicator? OK we'll put that one aside for a moment. Thermally protected. You are already protected by the fuse or breaker in the pedestal. The rest are just fluff.

So what is a surge? Honestly I have no idea. I have never seen one in my life (and I got about $40k worth of monitoring equipment on my incoming lines at work). I have only rarely seen a voltage dip and those are usually not that long lasting and occur if a line breaks (like a car hits a pole and the line breaks and arcs across the air gap till the substation trips). I imagine that a substandard or poorly designed electrical system in a campground could possibly have a voltage problem, but I don't see how these things can correct that. They can't make up the low voltage.

Power companies work awfully hard to keep the mains within tolerance. ANSI C84.1-2016 standard allows up to +105% and -90% for class A Utilization and +105.8 and -86.67% on Class B Utilization. (B has a rated short-time withstand current, A does not). That means you can have down to 108 volts (RMS) on a nominal 120 outlet and still be in tolerance on a Class A system. A few voltage-sensative things might be impacted. Like an old CRT TV would have the picture shrink a bit and your microwave might hum differently, but it won't hurt anything. But all modern electronics use switching power supplies to make DC (usually far under 120volt) that actually powers the devices, and they are pretty tolerant to low voltage.

'Surges' for the sake of this discussion are (I suppose) to be high-voltage transients on the incoming lines. Again, I have never, not once seen a high voltage condition on my incoming at work. My main substation is set to actually trip off at 106% voltage and again, I have never seen it do that.

Now when some people speak of "surges" they actually mean lighting strikes on power lines. This is exceedingly rare. The power companies do not want their equipment destroyed by lightning strikes. The power lines are usually protected by "Static lines" that shunt lightning strikes to ground. A lightning bolt can travel thru 20 miles of air (a good insulator) so the 4 or 5 inches of plastic that is your "Surge suppressor" isn't going to do much good to stop it if lightning actually struck a power line. The one popular unit is rated at "3850" Joule. That is minuscule, or about one watt-hour. A typical lightning bolt has over 1000 megajoule (1 billion joules) of energy in it. Your little hunk of plastic would vaporize, and the ionized gasses from it would provide a conductive path thru it. Then again, you'd probably have bigger problems than your DVD player getting fried at this point. Look at it this way, how many times have you sat at home in a thunderstorm and watched the lights get brighter due to lightning? I bet its about zero.

Those cheesy "Surge suppressors" that you used to get to plug in your PC or fax machine are simply MOV (Metal Oxide Varistors) that turn conductive at a set voltage. They usually set them a volt or two above nominal 120. Anytime you exceed that voltage (and mind you, you would still be in tolerance to the ANSI spec) would cause the MOV to conduct straight across the hot and neutral legs. It would blow apart, make some smoke and a flash, maybe melt the case a little and trip the breaker. When that happened, people would stare in astonishment on how that little plug-in device saved their PC from obliteration from a lightning strike. I imagine that anyone with an RV style surge protector feels the same way when it trips out in the middle of the night and takes down your whole AC system. Hell... If I designed them, I would make them nuisance trip every so often so people feel like it saved their electrical bacon, and that they got some worth for their money, other than a few blinky LEDs.

Anyway... I know I won't convince anyone to jettison their surge suppressor. But just remember, its like that travel insurance you get from the machine at the airport. It makes you feel better, but in the end, it really does nothing at all.

Tim

[bob213]

Cowracer...I have seen you post this before and you may be correct about a surge protector. Certain aspects may be true for an EMS unit as well. I can tell you from my own experience that my EMS has shut me down on at least 5 occasions for either high voltage or under voltage. Under voltage worries me more than a surge since we camp in extreme temps where everyone is running one to three A/C units. Most older RV parks are not set up for this draw on their system and voltage drops below what I consider safe for my unit. If that's all I get out of my EMS it's worth it to me.

[pdqparalegal1]

You're just trying to confuse me with facts


Good post.

[Cowracer]

Originally Posted by bob213

Cowracer...I have seen you post this before and you may be correct about a surge protector. Certain aspects may be true for an EMS unit as well. I can tell you from my own experience that my EMS has shut me down on at least 5 occasions for either high voltage or under voltage. Under voltage worries me more than a surge since we camp in extreme temps where everyone is running one to three A/C units. Most older RV parks are not set up for this draw on their system and voltage drops below what I consider safe for my unit. If that's all I get out of my EMS it's worth it to me.

So what do you do, then? Leave?

Some people seem to think that the surge protector or EMS (same thing to me) will CORRECT a low volt condition. It will not. It will just shut off your electricity (probably when i doesnt even need to) and leave you in the dark.

One would think that a system loaded up so bad to drop to 86% nominal voltage would be blowing branch circuit fuses like crazy.

Tim

[CurtPutnam]

I bought our Progressive EMS more for brownout control than for over voltage.

[Tx2Stepn]

Originally Posted by Cowracer

Offering a contrary opinion...

I am a 25+ year experienced Electrical Engineer (specializing in Control, automation and power distribution systems) and I'd never waste my money on anything like a "surge protector". I've never had one on anything I own (Camper, household or industrial) and never had anything damaged by a surge. The only benefit they provide is telling you when your pedestal is wired incorrectly and a cheap, $20 tester will do that.

Lets look at what these things are supposed to do for you: (taken directly from a popular brands website)



The first two are easily tested by that $20 tester. Surge failure indicator? OK we'll put that one aside for a moment. Thermally protected. You are already protected by the fuse or breaker in the pedestal. The rest are just fluff.

So what is a surge? Honestly I have no idea. I have never seen one in my life (and I got about $40k worth of monitoring equipment on my incoming lines at work). I have only rarely seen a voltage dip and those are usually not that long lasting and occur if a line breaks (like a car hits a pole and the line breaks and arcs across the air gap till the substation trips). I imagine that a substandard or poorly designed electrical system in a campground could possibly have a voltage problem, but I don't see how these things can correct that. They can't make up the low voltage.

Power companies work awfully hard to keep the mains within tolerance. ANSI C84.1-2016 standard allows up to +105% and -90% for class A Utilization and +105.8 and -86.67% on Class B Utilization. (B has a rated short-time withstand current, A does not). That means you can have down to 108 volts (RMS) on a nominal 120 outlet and still be in tolerance on a Class A system. A few voltage-sensative things might be impacted. Like an old CRT TV would have the picture shrink a bit and your microwave might hum differently, but it won't hurt anything. But all modern electronics use switching power supplies to make DC (usually far under 120volt) that actually powers the devices, and they are pretty tolerant to low voltage.

'Surges' for the sake of this discussion are (I suppose) to be high-voltage transients on the incoming lines. Again, I have never, not once seen a high voltage condition on my incoming at work. My main substation is set to actually trip off at 106% voltage and again, I have never seen it do that.

Now when some people speak of "surges" they actually mean lighting strikes on power lines. This is exceedingly rare. The power companies do not want their equipment destroyed by lightning strikes. The power lines are usually protected by "Static lines" that shunt lightning strikes to ground. A lightning bolt can travel thru 20 miles of air (a good insulator) so the 4 or 5 inches of plastic that is your "Surge suppressor" isn't going to do much good to stop it if lightning actually struck a power line. The one popular unit is rated at "3850" Joule. That is minuscule, or about one watt-hour. A typical lightning bolt has over 1000 megajoule (1 billion joules) of energy in it. Your little hunk of plastic would vaporize, and the ionized gasses from it would provide a conductive path thru it. Then again, you'd probably have bigger problems than your DVD player getting fried at this point. Look at it this way, how many times have you sat at home in a thunderstorm and watched the lights get brighter due to lightning? I bet its about zero.

Those cheesy "Surge suppressors" that you used to get to plug in your PC or fax machine are simply MOV (Metal Oxide Varistors) that turn conductive at a set voltage. They usually set them a volt or two above nominal 120. Anytime you exceed that voltage (and mind you, you would still be in tolerance to the ANSI spec) would cause the MOV to conduct straight across the hot and neutral legs. It would blow apart, make some smoke and a flash, maybe melt the case a little and trip the breaker. When that happened, people would stare in astonishment on how that little plug-in device saved their PC from obliteration from a lightning strike. I imagine that anyone with an RV style surge protector feels the same way when it trips out in the middle of the night and takes down your whole AC system. Hell... If I designed them, I would make them nuisance trip every so often so people feel like it saved their electrical bacon, and that they got some worth for their money, other than a few blinky LEDs.

Anyway... I know I won't convince anyone to jettison their surge suppressor. But just remember, its like that travel insurance you get from the machine at the airport. It makes you feel better, but in the end, it really does nothing at all.

Tim

I think it must depend on where you live. As I stated we were hit by lightning and the electric company "fixed" the issue and left the voltage at 140. We figured out by how our toaster was burning the toast on lowest setting. We were hit by lightning 3xs that year and the only things we lost in the house was the router that the internet company said to not plug into a surge protector. I lost a router on 2 of the hits. If you dont use 1 I would unplug it during any storms just to be safe.

[67L48]

Originally Posted by Cowracer

[...] I am a 25+ year experienced Electrical Engineer (specializing in Control, automation and power distribution systems) [...]

Originally Posted by Cowracer

[...] surge protector or EMS (same thing to me) [...]

A guy with 25+ years of experience thinks a surge protector is the same thing as an EMS?

[Cowracer]

Originally Posted by Tx2Stepn

I think it must depend on where you live. As I stated we were hit by lightning and the electric company "fixed" the issue and left the voltage at 140. We figured out by how our toaster was burning the toast on lowest setting. We were hit by lightning 3xs that year and the only things we lost in the house was the router that the internet company said to not plug into a surge protector. I lost a router on 2 of the hits. If you dont use 1 I would unplug it during any storms just to be safe.

Not really sure how you can get 140 volt like that. Maybe they changed the xfmr and used the wrong tap??? Are you rural? If so, you might have a SWER (Single Wire Earth Return) distribution system. You see it in sparsely populated areas due to the fact that its cheap. Like the name says, you only need one wire to provide service. Your step-down xfmr has 2 secondarys, wound in opposite directions with the neutral tied directly to ground. That way you can get one half of the 240 off one secondary and the other half from the other one. They can be a little dicey as you are relying on a ground rod to provide neutral between the two. In real dry soil, the current flow in the ground rod may be insufficient, causing the ground rod to "float" at a higher voltage than true ground, effectively reducing voltage from hot to neutral. But I don't see how it can raise voltage...

My lake lot is SWER severed and despite me knowing what the hell I am doing (electrically speaking) , I still have issues running a GFCI in the cabin. My A/C units came with GFCI built into the cords and I had to cut them off and just go to straight plugs because they would trip from time to time. Its easy to tell if you are on a SWER. You will see only one xfmr on the pole, with a single wire going to it from the overhead lines.

If you are really worried about low voltage, an Auto-transformer would be ideal, however it will use more of the already limited power available in your branch circuit to raise your voltage, at the expense of possibly lowering voltage available to other campers on the same circuit. This has been know to create tense situations between campers with auto-transformers and guys with EMS systems that trip off because of the voltage drop. Guys like me without either don't seem to care.

Tim

[Cowracer]

Originally Posted by 67L48

A guy with 25+ years of experience thinks a surge protector is the same thing as an EMS?

No. I just lump them together as the same thing. (i.e. useless).

Tim

[cavie]

Originally Posted by 67L48

A guy with 25+ years of experience thinks a surge protector is the same thing as an EMS?

You'll need to excuse him. He is an electrical engineer. He can't help it.

[llr]

Cowracer, I tend to agree with you however I think there is one condition an EMS will help with, a poor connection in the campground wiring. A no load test will show good with very poor connections, live monitoring will find them.

I don't have an EMS but will probably get an internal one just for protection from a bad neutral on 50A service.