Updates on surge protectors?

[Scott J-24]

I have been looking at past threads on surge protectors and whether they are worth the money or not. These past threads appear to be at least 5 years old (but I could be wrong). Opinions were split but many felt they were a wast of money that could be better spent somewhere else. Is this still the case or has the technology / systems in recent AS TTs no benefit from a good quality (expensive?) surge protection device? I am leaning towards purchasing one, but being a rookie, I thought I should ask the experts first.

[mistermcfrug]

I won't claim to be an expert but I bought one based on common sense. You've got a 2009 27' International that probably cost, what, $70,000. A high end surge protector can be used to protect on the converter, inverter and other wiring. I bought a high end model (I can't remember the name) but it shuts off power to the trailer not just in case of high voltage but also if volts drops below 90 or something. It does other checks like for polarity and others. I think you want that wide ranging protection because you never know where you'll be staying and what the RV park screwed up. Bottom line to me: it is very cheap protection compared to your initial investment. There are various brands. Mine cost $280.

[smhx4]

I'm not expert either. But low voltage broke our AC in our 07 AS. We have a surge protector, surge guard 50A, ready to go when we get our international. We have two ACs in this unit. It also protects from both low and high voltage.

It cost 330$ on eBay, 420$ at the AS dealer. We needed a 50 amp model which raised the price some.

[Gene]

I ordered one from Camping World. They had a coupon deal—it expired several days ago—and got an inline version. It was about $205, about 30% off list price. Those cost less than the ones that plug into the electrical pedestal at a campground. You do have to do some electrical wiring, but just what, I am unsure of because I haven't seen it yet except on a picture on the internet. I expect it will require a junction box and cover, Romex connectors, some large wire nuts, lots of electrical tape and #10 wire (for 30 amp; for 50 amp, #8 or 6). No one can steal it unless they steal the whole trailer. There are locking devices available for extra $ for those.

'Mcfrug said it well—the risk for wholesale replacement of appliances, converter, solar controller, vs. the price of the surge protector weighs in favor of getting one, something I have avoided for years. But after spending a bunch on a new solar system and converter, I want to protect my investment.

Surges always occur in power systems and lightning may make it a lot worse. You never know just what quality of electricity you have and whether the campground has sufficient grounding to prevent major surges from lightning.

I'm not sure wire nuts are appropriate for an RV because they can loosen and are subject to shaking. I can use tape to stabilize them, but something like split bolt connectors are a stronger splice. They have to be insulated and I don't like using tape on them. I am going to a Home Depot today to see what kind of insulating devices they may have.

Gene

[sailorii]

I'm like the original poster. Know I need something given where we frequently have the trailer. Is there anyone with any experience with a Hughes RV Autoformer? This device evidently boosts low voltage up to 10% with the existing service when required. Not sure if it will disconnect to protect AC, etc. with too low voltage or not? Or, do you need a surge protector too. If so, the solution get quite pricy.

[Gene]

Sailer', I never heard of this device, but the formula for volts, amps and watts is to be respected. You say it only operates when needed, but what is the effect on amps and watts?

If you boost volts by 10%, you will probably have fewer watts and amps—10% less. On a 20 amp circuit that would be instead of 2,400 watts, you have 2,160—and that is if you have 120 v. Or 18 amps. An A/C likes to have all those watts and amps whenever the compressor starts, so I would be careful of just how this thing works. Total load on the system would be similarly affected. Instead of a 30 amp total capacity (again, if you have 120 v.), you would have 27 and a microwave + a toaster + lights + TV might be affected. Or, if the campground only has 90 volts, the most you can get is 99 volts, not enough for appliances and especially for electronics. I think it may be safer to have a shut off system for shore power and just use batteries and propane.

I admit to being skeptical and may be getting the formula wrong. We will probably see posts by those who know more soon enough.

Gene

[Air Apparent]

Scott:

I bought one (a 15amp) when I had my popup. I kept it when I purchased my Airstream. We keep our Airstream on an RV lot that we own and keep the power on at all times during the summer for our fridge. Several years ago during the week a lighting strike hit near our Airstream and fried out the surge protector as well as the 30 amp recepticle. I had no damage to the electronics in our Airstream. I replaced the 30 amp receptice and replaced my surge protector to a 30 amp protector. Based on this experience I will not be without one.

[davidz71]

I've had the 30 amp Hughes Autoformer for around 5 years and it has worked without a hitch. I feel comfortable that under/over voltage are controlled and the important electrical appliances such as the AC and converter are protected.

[Silver Goose]

Originally Posted by CrawfordGene

... You do have to do some electrical wiring, but just what, I am unsure of because I haven't seen it yet except on a picture on the internet...Gene

I picked up a Surgeguard 30 with remote display at a Samboree a couple of years ago. I assume you purchased something like it. You may need to pickup a few feet of cable from your hardware store if there isn't enough slack in your trailer. With the power disconnected from the trailer of course, I pulled out my AC breaker box and disconnected the hot/neutral/ground leads from the box and reconnected them to the input side of the Surgeguard (black to brass, white to aluminum, green to green). The connections are the screw down clamps just like in your break box. Then did the same with a length of wire from the output side and back to the terminals on the breaker box. The remote display is connected with a cable similar to a telephone wire with the RJ16 connectors on each end. I surface mounted the display above the battery disconnect switch near the entry and threaded the cable behind the sink to the fuse box area and plugged it into the protector. I then mounted it where it had some air flow around it in the cabinet and pushed the breaker box back into place. You won't need any other parts

There was a jumper inside that could be changed to how long you want power to remain off after an outage. I think the choices were 15 seconds or 3 minutes. When you plug in the trailer, it will delay applying power to the breakers for the time set by the jumper. If the pedestal is wired incorrectly, or the voltage is too high or too low, it will post a code on the display and not apply power until the fault is corrected. As I recall, it kills power at 102 volts, which some feel is too low for the A/C and if it goes above 132 volts.

The display cycles through line voltage, current draw, frequency and last unreset fault code.

Several years ago I plugged into a pedestal that put the hot line to the trailer frame! Was kind of exciting when I touched the trailer. This device will prevent that.

[Silver Goose]

Originally Posted by CrawfordGene

...I admit to being skeptical and may be getting the formula wrong. We will probably see posts by those who know more soon enough....Gene

I too have been skeptical about these transformers having seen them advertised, but never really gave them too much thought until this discussion came up. The relationship between volts and amps should be well understood by anyone who has taken courses in basic AC and DC circuits.

In a nutshell if you have a transformer wound to boost voltage by 10% and you apply 105 VAC to the input, you will get about 115 VAC out of it. To keep numbers round, if your A/C requires 15A to operate at 115V, it will actually draw more amps at lower voltages and this is where the damage to the sealed motor/compressor comes in as higher current demand generates more heat within the motor. Some will experience the 20A breaker tripping on the A/C circuit when the voltage gets too low.

By boosting the voltage on the secondary side of transformer, the A/C will run it its comfort zone, but the transformer has to draw more amps from the pedestal to do this. If my thinking is correct, using a transformer will help with the low voltage problem for the A/C, but you have to keep in mind that additional electrical loads will also multiply the load on the primary and you may have to run the fridge on gas and turn off the TV while running the microwave to keep from tripping the pedestal's breaker.

[Silver Goose]

Originally Posted by davidz71

I've had the 30 amp Hughes Autoformer for around 5 years and it has worked without a hitch. I feel comfortable that under/over voltage are controlled and the important electrical appliances such as the AC and converter are protected.

How much heat does this transformer produce? Do you think it could be hardwired and mounted inside the trailer? Does it make any appreciable noise, hum? I've only seen them advertised as a portable unit that you sit outside. Never considered if it was just for convenience for the average user, or maybe they get too warm to put in a confined area.

[Gene]

Yankee, thanks for the info. I guess I got it backwards on the formula, but you confirm my skepticism.

My converter is under the bed, too far and complicated to run a telephone line anywhere that far away to the battery disconnect area. Aren't the 120 v. wires connected directly to the unit? Yes, I ordered the 30 amp Surgeguard.

Gene

[Frank&Mike]

I had posted a thread last year asking for input on surge protection devices as well. I took no action to purchase one based upon some of the feedback I received that these are not worth the money.

Well, wouldn't you know it, we attended a Rally at a City ran RV park that we had been warned it had "known" electrical issues. Guess what happened, our fridge stopped working after that Rally. Guess what happened to the people in the space next to us, their A/C unit quit working. We ended up having to spend $1300 to replace a fridge that I think could have been avoided had we made that small $300 investment.

I'm a believer now. I'm in process of shopping around for one and plan to purchase it for the Airstream that we have now and will be using it on our upcoming trip in a couple weeks.

[davidz71]

Originally Posted by YankeeDoodle

How much heat does this transformer produce? Do you think it could be hardwired and mounted inside the trailer? Does it make any appreciable noise, hum? I've only seen them advertised as a portable unit that you sit outside. Never considered if it was just for convenience for the average user, or maybe they get too warm to put in a confined area.

There is an installation kit on the Hughes site which allows you to mount the unit inside a compartment. Mine is mounted 4 ft. from the junction box where the 30 amp cord enters the trailer. This is underneath my streetside rear corner bed. The box was placed inside a small plastic crate similar to a milk crate but considerably smaller. This was to prevent it from tipping over and to allow ventilation on all sides if needed. The box stays cool so I guess ventilation wasn't an issue. I have never heard the box hum so it isn't an issue either. Check out the website under Products for the 30 amp install kit. Hughes Autoformers

[Silver Goose]

Originally Posted by CrawfordGene

...My converter is under the bed, too far and complicated to run a telephone line anywhere that far away to the battery disconnect area. Aren't the 120 v. wires connected directly to the unit? ...Gene

For me, there was space behind the converter/breaker box in the galley area and with my floor plan the battery disco switch is adjacent to the entry door so that was the logical location for me and I had to drill one small inconspicuous hole for the display cable. Do you have an accessible area where the 30A power enters the coach? The Surgeguard can go anywhere in the line between the breakers and the point where the 30A line enters. I think the cable for the display panel was about 50' long. I would choose a location for the unit so that it could be accessible for service if needed.

Here's a snapshot of the 50A model, the wiring is the same except the 30A uses one less wire.

[Silver Goose]

Originally Posted by davidz71

...Mine is mounted 4 ft. from the junction box where the 30 amp cord enters the trailer. This is underneath my streetside rear corner bed. The box was placed inside a small plastic crate similar to a milk crate but considerably smaller. This was to prevent it from tipping over and to allow ventilation on all sides if needed. The box stays cool so I guess ventilation wasn't an issue. I have never heard the box hum so it isn't an issue either...

Thanks for the additional info. That makes it more interesting.

[Scott J-24]

We went to CW this afternoon and purchased a 30 amp Surge Guard (model 34730). This is the plug-in unit not the hardwired unit. Glad we now have some protection from "sketchy" CG power posts. Thanks for all of the quick responses to my question, I feel much better about spending a relatively small amount of money to protect our AS.

[Gene]

Yankee, thanks for posting the instructions. Not enough bandwidth to get to see them here, so I'll have to wait until we get home tomorrow.

Gene

[Gene]

I came home and the box with the surge protector was here. This model is different than the one Yankee' described. It is one piece—no separate monitor. Wires connect at the top and bottom and they are not inside much protection against shocks. You have to strip back the outer insulation on the 120 v. wires to get the 3 wires (4 for 240 v.) into the clamps. I haven't looked on the box to see what organization approved this, but it certainly wouldn't pass most codes.

I could mount it below the bed or maybe on a nearby wall and using a lot of tape, make it safe. I want it somewhere where I can see the lights on it so I can tell what is happening, so it has to be easy to see.

I don't know of any other brand for RV's and don't want to go through the hassle of returning it, so I guess I'll figure out something. If I had known how it is designed, I would have looked harder for alternatives.

Gene

[Jammer]

Originally Posted by CrawfordGene

Sailer', I never heard of this device, but the formula for volts, amps and watts is to be respected. You say it only operates when needed, but what is the effect on amps and watts?

If you boost volts by 10%, you will probably have fewer watts and amps—10% less. On a 20 amp circuit that would be instead of 2,400 watts, you have 2,160—and that is if you have 120 v. Or 18 amps. An A/C likes to have all those watts and amps whenever the compressor starts, so I would be careful of just how this thing works. Total load on the system would be similarly affected. Instead of a 30 amp total capacity (again, if you have 120 v.), you would have 27 and a microwave + a toaster + lights + TV might be affected. Or, if the campground only has 90 volts, the most you can get is 99 volts, not enough for appliances and especially for electronics. I think it may be safer to have a shut off system for shore power and just use batteries and propane.

I admit to being skeptical and may be getting the formula wrong. We will probably see posts by those who know more soon enough.

Gene

THe Hughes Autoformer, and competing devices that operate on the same principle, are automatic buck-boost autotransformers. For the 30a units, electrically, they consist of a transformer with a 115 volt primary and a low-voltage secondary (Probably 18 or 24 volts, I've never had one apart) with several taps (probably every 6 volts). If the campground voltage is low the secondary windings are used to boost the voltage. So for example to get 12 more volts the 12 volt tap on the secondary would be used. If the campground voltage is high the phase of the secondary is reversed to lower the voltage. The tap selection is controlled electronically.

50a units are similar but have additional components to be able to work on both 120v legs.

The current draw of the primary winding of the transformer adds to the overall draw from the campground pedestal. So for example if the unit is providing an 18 volt boost at 20 amps to the trailer it will draw 23 amps from the campground ( (1+18/120) * 20).

The autoformers also have MOV (metal oxide varistor) surge protectors which provide some protection against voltage spikes. Spikes in the range they can protect against are rare in modern campgrounds because modern campgrounds use underground wiring that isn't as suspectible to large spikes from lightning as overhead wires used in the past.