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Old 04-18-2015, 05:07 PM   #1
ke0me
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Default Surge Guard - dead

got into camp today, trailer has been at the shop for various maintenance stuff.

Plugged in surge guard and power cable as always, it counted to 128 seconds, then said I was good with 120 vac.

However, no power inside trailer.
Pulled surge guard off power cable, plugged cable into pedestal, power in trailer.

So, any ideas on anything I can do to test the unit?

It was sitting inside a storage compartment for 3 days here in Ft Myers, FL.

Possible heat soaked and needed to cool off?

its about 1 year old , and being full time, its been in use every day.
model number is 34730, the 30 amp unit.

just not comfortable without the protection, but not ready to drop another
$ 250-300 just yet.
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Old 04-18-2015, 08:40 PM   #2
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Model 34730, OK. Does it also have a brand name?
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Old 04-18-2015, 09:02 PM   #3
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Surge Guard actually is the brand name.

Yours is like this one? They'll sell a new one here for $179.

http://tweetys.com/portable-surge-gu...VVfxoCUzXw_wcB

You can find a .pdf manual on this page:

http://trci.net/products/surge-guard...e-wlcd-display

What, if anything, are the lights on the unit doing?
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Old 04-19-2015, 12:52 AM   #4
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Do you need it? What do you expect it to protect you from?

There are three possible conditions from which you may need protection: (1) overvoltage; (2) undervoltage; (3) lightning-induced spikes.

Overvoltage
This will not occur on the power lines. Trust me, I'm an electrical engineer. It can occur in your RV, but only because of an open ground (neutral) that, in effect, places your 120v sockets across the 240v lines. This is more likely to occur in your RV's wiring than in the shore-power supply, but it can occur in the pedestal and sometimes does.

Undervoltage
This may occur anywhere, and is not rare in RV parks that have inadequate wiring. It can also occur on one 120v leg when the other leg gets overvoltage because of an open ground (open neutral).

Lightning-induced spikes
These may occur anywhere during thunderstorms.

Now then: what equipment do you wish to protect from these dangers?
Nearly everything in any RV I ever saw runs on the house batteries (and converter). Nothing that runs at 12v can be hurt by a problem in the shore power. Take that as gospel.

What runs on the shore power, then?

Only a few things: Air conditioners, the converter/charger, microwave, electric space heaters, most TVs, desktop PCs, and any electronics that runs from a wall wart. Let's look at each.

Air conditioners: These can be damaged by extreme overvoltage or undervoltage, but it has to be pretty extreme. Incorrect voltage may cause the compressor motor and fan motors to overheat, but typically they have thermal breakers that shut them off when they get hot. An undervoltage so great that the motor doesn't spin up enough to trip the centrifugal switch can burn up the starting capacitor and maybe even the starting windings -- the compressor is usually a capacitor-start, induction-run motor. Not really much danger there because it doesn't happen instantaneously, but you can avoid that by simple tests when first hooking up. I'll discuss this below. Lightning transients are not going to hurt them at all, being very short, unless the lightning is so close that nothing can stop it. In that case the surge protector won't do any good either.

Microwave oven: This can be hurt by overvoltage, but not by undervoltage, which will simply cause it not to work, or not work very well. Lightning transients, if very strong, might damage a microwave, so see below.

Electric space heaters: can be hurt by large overvoltage that continues for a long time, but not by undervoltage. Immune to lightning surges.

TVs: impossible to hurt by undervoltage, but large overvoltages can hurt them. Lightning can hurt them, too; see below.

Desktop PCs: Typically these won't be hurt by either overvoltage or undervoltage, because the power supply will protect itself by shutting down. Very little danger there. Can be hurt by lightning; see below.

Converter/charger: some are poorly designed and may be susceptible to overvoltage damage.

Anything that runs on a wall wart: Overvoltage may fry the wall wart, but typically won't hurt whatever the wall wart is feeding. Undervoltage won't hurt them. Lightning can fry the wall wart but usually not whatever it's feeding, but with lightning there are no guarantees for anything electronic.

My electric beard trimmer and Water Pik run on 120v too, but I can't imagine any damage to these from overvoltage, undervoltage, or any lightning hit that doesn't burn down the motor home.

What do I do? I certainly won't spend hundreds for a fancy device whose sales pitch, like IBM's in the early days, is based on inducing what is known in the mainframe industry as FUD for Fear, Uncertainty and Doubt.

For the few things that are in danger from lightning, I use small, inexpensive throw-away surge protectors from Lowe's or Home Depot.

Overvoltage can occur only as a result of an open neutral. There are many inexpensive testers that can detect open neutrals. By inexpensive, I mean less than ten bucks. Buy them at Lowe's, Home Depot, Northern Tool, Harbor Freight, or on eBay. You don't need a 240v device; a 120v device will work just fine, even on a 240v, 50a RV. Read on to see why.

Undervoltage can be caused by an open neutral, but only when it's also causing an overvoltage in some other circuit. Undervoltage can also be caused by inadequate wiring in the RV park.

Buy a cheap circuit tester that can detect open neutral by plugging into a 120v outlet. Also buy a little expanded-scale voltmeter that plugs into a 120v outlet.

Before plugging into the RV park's pedestal, test the voltage at a 120v outlet in the pedestal (the household-type outlet in the pedestal). If it's over 130v or under 100v, don't plug your RV into it. Then plug in the open-neutral tester there, and assure that the correct lights light up, so you're pretty sure (not yet certain) there's no open neutral.

Then, with all 120v appliances including the converter/charger turned off, hook up your shore power. Make the same checks inside the RV. If all is well, turn on one robust appliance such as a space heater, toaster, hot plate, or roof A/C, and quickly repeat the tests, especially the voltage tests. If within specs (about 100-125 volts this time), all is well and you can stop worrying.

Why does this work? Your cheap little throw-away surge protectors are protecting the few things that need lightning protection, and you've specifically tested the voltage, both at no-load and at single-load conditions.

Generalized undervoltage isn't rare in RV parks, but you've tested for it with the voltmeter. Open neutrals are a little rarer, but you tested for that too.

Let's discuss that open neutral a bit. The pedestal supplies a 120v/240v circuit. Each of the two legs supplies 120v (between the leg and the neutral), and there is 240v between the two legs. The neutral is maintained midway between. The 240v is always there in the pedestal, even if you have a 30a RV that connects only to one leg. If your shore-power connection is 50a, you're using both legs. (If you use an adapter to plug your 30a RV into a 50a pedestal, you're connecting both legs of your RV to a single 120v leg of the pedestal supply, which is fine because nothing in your RV requires 240v; your appliances are all 120v devices).

You tested at the pedestal and found 120v, close enough, with no load.

Then you tested inside your RV, same thing.

Then you turned on one fairly large load (space heater, toaster, etc) in your RV. If the neutral were open (or partly open), the voltage would drop on that leg and soar on the other leg (which has no load). Your voltage test would detect it either way, no matter which leg youre reading. If that single voltage test was OK, then you're safe from any problems with the shore power. Pop a cool one (I prefer root beer), and then take a nap.

Even if I had one of those god-awful-expensive devices the RV dealers want to sell you, Id do these checks anyway, because the god-awful-expensive device might itself have an open neutral or a defective connector; or my shore-power cable could have an open neutral.

You can do all this with ten or twenty bucks worth of equipment that you probably already own (should own!) anyway. Why spend hundreds for stuff whose whole sales pitch is based on inspiring fear of the unknown?
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Old 04-19-2015, 07:44 AM   #5
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There is an argument that a surge protector is superfluous. Maybe so.

I have my outlet checker I can check the pedestal with, and a voltmeter that plugs into any outlet to monitor voltage. And a real DVM if I ever doubt it's accuracy. So these help with miss-wiring and over/under voltage.

In case of thunderstorms I have (only once) disconnected from the pedestal.

On the other hand I didn't go out in the woods to sit and stare at a voltmeter or brush up on my engineering skills. I go out there to be unbothered. Un-worried. Un-concerned.

So if dirty power keeps you up at night, replace your protector. But don't pay more than you have to for one.
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Old 04-19-2015, 01:41 PM   #6
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You can open it up.. Odds are the solnoid (relay) is bad.. but try this

Before you open it up plug it in again, You can use a 30-15 adapter and do this inside if you like...128 seconds later you should hear a loud CLUNK..If you do then the electronics ar working,,The solonoid did not make contact..May just need cleaning.
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Old 04-19-2015, 07:02 PM   #7
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A two wire appliance will not work with an open neutral, RV panels are wired as a sub panel with an isolated neutral.
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Old 04-19-2015, 09:57 PM   #8
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Quote:
Originally Posted by N3LYT View Post
A two wire appliance will not work with an open neutral, ...
A bit simplistic, and not true on a three-wire or four-wire 120/240 supply.

Consider the first of two schematics. It represents 120/240 house (or RV) wiring with two appliances. One has 100 ohms resistance (maybe a 150 watt lamp) and the other has 1000 ohms (maybe a 15 watt lamp; the resistances are approximate). One lamp is on one leg of the 120/240 supply, and the other is on the opposite leg. Each lamp has 120v across it and all is well.

Now, in the second schematic, the neutral has opened, perhaps because of a dirty connector, or a broken wire, or a loose screw. The 240v is across the two resistors in series, 1100 ohms total. The current in both lamps is about 0.218 amperes. The voltage across the 100 ohm lamp is 21.8 volts, and the voltage across the 1000 ohm lamp is 218 volts. The 100 ohm (150 watt) lamp is dissipating 4.76 watts, not enough to light it up; but the 1000 ohm (15 watt) lamp is dissipating 47.6 watts and won't last very long.

Substitute your toaster and your soldering iron for the two lamps, and you'll soon need a new soldering iron.

So I guess your statement is almost true; a two-wire appliance won't work very long with an open neutral.

As for the isolated neutrals, they're isolated only from the service panel onward. There's only one neutral in the pedestal, and there's only one neutral in your shore-power cable, and most likely there's only one neutral all the way to that service panel (breaker panel) in your RV. Every neutral in the RV is connected to the one-and-only neutral in the shore-power cable and pedestal.
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Old 04-20-2015, 06:18 PM   #9
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Quote:
Originally Posted by NN5I View Post
A bit simplistic, and not true on a three-wire or four-wire 120/240 supply.

Consider the first of two schematics. It represents 120/240 house (or RV) wiring with two appliances. One has 100 ohms resistance (maybe a 150 watt lamp) and the other has 1000 ohms (maybe a 15 watt lamp; the resistances are approximate). One lamp is on one leg of the 120/240 supply, and the other is on the opposite leg. Each lamp has 120v across it and all is well.

Now, in the second schematic, the neutral has opened, perhaps because of a dirty connector, or a broken wire, or a loose screw. The 240v is across the two resistors in series, 1100 ohms total. The current in both lamps is about 0.218 amperes. The voltage across the 100 ohm lamp is 21.8 volts, and the voltage across the 1000 ohm lamp is 218 volts. The 100 ohm (150 watt) lamp is dissipating 4.76 watts, not enough to light it up; but the 1000 ohm (15 watt) lamp is dissipating 47.6 watts and won't last very long.

Substitute your toaster and your soldering iron for the two lamps, and you'll soon need a new soldering iron.

So I guess your statement is almost true; a two-wire appliance won't work very long with an open neutral.

As for the isolated neutrals, they're isolated only from the service panel onward. There's only one neutral in the pedestal, and there's only one neutral in your shore-power cable, and most likely there's only one neutral all the way to that service panel (breaker panel) in your RV. Every neutral in the RV is connected to the one-and-only neutral in the shore-power cable and pedestal.
Yes that could happen in a twin 120 volt 50 amp set up but not in a 30 amp. Some devices with a 3 pin plug could still work with out a neutral if they had a grounded frame common to the neutral but a two prong plug with an open neutral won't. The service panel is the source panel with the neutral and ground bonded together the camper is the sub panel with an isolated neutral.
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Old 04-20-2015, 06:46 PM   #10
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Default Surge Guard dead

I knew I came to the right place!!

10 replies in 1 day. That's phenomenal.

I posted essentially the same message on the rv owners website, no replies.

Now, down to business.

Thanks for the variety of answers. First I will do the clunk test. If that fails, then I can open it up and check the solenoid. If that's not the issue, then I might check and see if its under warranty.

The decision to replace it is one of risk and inconvenience. If a fault actually occurs and somehow damages electrical devices, I have insurance. However, that will be a hassle and I'm full time, so that can be expensive housing for a while.

I concur that if the lightning hits close enough, all bets are off.

Doing the checks described are well advised, but since I'm always in a bit of a hurry to set up camp, I just like to plug it in and check back in 2 minutes.

I will say it showed faults twice- which would have been found also with the testing method described.

---once at a relatives house, using 110VAC, he had an open neutral that the unit picked up.
---At a KOA in an undisclosed location, the wiring was so bad (old, undersized, whatever) that the surge guard tripped out on low voltage.

So, it looks like to me to be a " piece of mind versus piece of gold" issue.

Thanks again for the info, I'll keep u posted on what I find.
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Old 04-20-2015, 07:32 AM   #11
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Folks all this yammering about how 120/240 2/3/4 wire hookups is nice, and informative.

But has nothing to do with the O/P's problem

IT counted down,, IT said "POWER OK" (Green light)but NO power reached the coach.

Suspects are thus
1: Electronics...If this is the case there will be no CLUNK after 128 Seconds
2: Bad solenoid: Clunk,but no power to outlet
3: Bad outlet.

And the ever popular screw loose (Bad connection) Many RVers have a few screws loose.
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Old 04-20-2015, 07:53 AM   #12
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Quote:
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... has nothing to do with the O/P's problem ...

And the ever popular screw loose ... Many RVers have a few screws loose.
Of course you're absolutely right. Guilty as charged, your honor.
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Old 04-21-2015, 06:58 AM   #13
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Quote:
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Of course you're absolutely right. Guilty as charged, your honor.
Uh, I was refering to the kind that hold wires and stuff,,The ones you tighten with a screwdriver... But then on the other hand......

I see you read the line exactly as I intended it to be read.
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Old 04-21-2015, 05:33 PM   #14
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Default surge guard clunk

I tested the unit today.
plugged it in, counted to 128 seconds, and heard the clunk of the solenoid connecting. Green lights, 123V, 0 amps load.

No AC power at output.

So I guess next step is open it up and see if I see anything obvious.
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Old 04-20-2015, 06:36 PM   #15
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Actually it can happen to an RV with a 30-amp hookup. It depends upon where the neutral is open.

If the neutral is open, for example, at the camp's distribution panel, or somewhere between that panel and the pedestal, then the voltage at the pedestal can go wild. The reason is that the camp is wired for 120/240, with some 30-amp RVs on one side, some other 30-amp RVs on the other side, and 50-amp RVs on both. In that case, to understand it, look again at the two schematics and in your mind substitute RVs, instead of lamps, for the resistors.

Why is this worth understanding? Because, understanding it, someone may some day save his very own personal skin by testing for it before hooking up. Open neutrals in distribution panels are far from rare.
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Old 04-21-2015, 07:06 PM   #16
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Quote:
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Actually it can happen to an RV with a 30-amp hookup. It depends upon where the neutral is open.

If the neutral is open, for example, at the camp's distribution panel, or somewhere between that panel and the pedestal, then the voltage at the pedestal can go wild. The reason is that the camp is wired for 120/240, with some 30-amp RVs on one side, some other 30-amp RVs on the other side, and 50-amp RVs on both. In that case, to understand it, look again at the two schematics and in your mind substitute RVs, instead of lamps, for the resistors.

Why is this worth understanding? Because, understanding it, someone may some day save his very own personal skin by testing for it before hooking up. Open neutrals in distribution panels are far from rare.
That is true of the service but the camper is a sub panel and the neutral floats in a 30 amp box so the neutral at the site must have a neutral connection in order to cause an issue. You are right cheap insurance is a 3 light tester mine never gets unplugged.
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Old 04-23-2015, 07:54 PM   #17
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As an aside:

A fellow had a fine pocket watch he had inherited from his grandfather. One day it just quit working. He looks up a reputable watch repair shop in the yellow pages and takes it there.

The watch maker carefully examines the watch and has a lot of nice things to say about it. "let's get the back off and see what's going on in there."

Upon removal of the back a tiny bug falls out onto the counter. "Oh, I see. So sorry, it seems your engineer has died."

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Old 04-24-2015, 07:50 AM   #18
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IF the neutral was open the Surge Guard will detect and report it.

IF the solenoid is not closing properly (not making contact) or the outlet is wore out.. What you will get is exactly what he is seeing.. Normal operation right up to the CLUNK of the magnets pulling in the contactors.. BUT NO POWER.

Can also be caused by a screw loose inside the unit.
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Old 06-19-2015, 08:15 PM   #19
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Default Surge Guard Update

Ive been distracted for a few weeks with other issues (medical related), and finally called TRC, maker of the Surge Guard.

I talked to Cust Serv and they are going to replace it free, even though it's a month out of warranty.

A company that stands behind its product should be noted as providing exceptional customer service.

PS - for the last few days, temp has been in the 100 range, so the air cond runs constantly in the afternoon. I noticed that the voltage was getting low, but still over 108 volts.

As the voltage drops, the Amps increase so I was sure to unplug/turn off anything not needed just in case.
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Old 06-20-2015, 06:41 AM   #20
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Thanks for that Carl.. I was speaking of screws that hold wires to terminals, circuit breakers and other types of screws but yes.

I do phrase it that way for the laughs. So thanks.

(There are those who think that *I* prsonally (not the RV) have a few screws loose as well but hey.. Sanity is so boring)
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