Locking portable surge protectors and insurance coverage

[Seann45]

Originally Posted by jdorant

A discussion I just had last night... I'm thinking of a surge protector but not sure if I want to shell out $300 for it right now when I have many other things that need to be bought for the new camper as well.

I would imagine I would be covered say I did not buy a surge protecter and something happened to my electronics in the camper because of it. There is no neglect as you are not required to buy this for your camper and they are not built with it. Theoretically, the fuses should protect you trailer from such surges. I realize it would be an aggravation say something did happen, but I'm thinking I want to put this mod off 1 season and spend my money elsewhere this year. Thoughts?

JD even if ins covers your loss of all your electronics how much is a ruined vacation worth? Mine has "saved" the RV twice in 10 years... it's paid for itself.

[tinlizzie23]

Right on, Seann. A good surge protector is a very good investment, and if it saves even one vacation by saving the camper electronics, it is well worth the cost, IMHO. Put another way, you may have dodged the bullet 99 times out of 99, but it's that 100th time that will make you learn the hard way.

[Barndog]

Jdorant: I have a 30amp portable ems from Progressive Industries and like Clubhouse i am more concerned with low voltage than experiencing a high voltage spike. I believe I paid $256.00 online at AdventureRV.net. With so many older campgrounds out there I want to have the added peace of mind knowing that I am protecting my rv. I also check polarity and voltage with a multimeter before I hook up.

[westom]

Originally Posted by Raugustin

What we must consider is that there are breakers that protect against over current which is caused by a short circuit or sustained ondervoltage. It is the under voltage or brown out condition that is the problem today, over voltage (not surge or transient voltage) is not common.

That is three completely different anomalies. a) Circuit breakers are for a current not previously discussed. For example, circuit breakers will disconnect AC power maybe as much as two hours later when 20 amps is flowing through a 15 amp breaker. Or faster when the current is even higher. That anomaly (called a surge) was not even mentioned in any previous discussion.

The expensive device typically located inside the is b) only for minor over and under voltages. It disconnects when the 120 volts might rise to 140 volts. Or the more common 120 volts dropping to 95 volts. Those surges or sags made irrelevant by disconnecting.

Another completely different device c) is ineffective if located in that same interior location. Designed for a third surge such as a 10,000 amps transient flowing for microseconds. Disconnecting will not protect from this anomaly. MOVs in the above second b) device do not even claim to protect from this anomaly. Price is also irrelevant those MOVs cost pennies. Only device for that third type anomaly requires the protector to be at the pedestal. Wire length determines how effective that protector.

Circuit breakers a) are for a surge known as an overcurrent. Breakers might disconnect power in seconds, minutes or even an hour. A protector located in an RV b) is for a surge more commonly known as voltage variations. It disconnects when voltage varies excessively. The c) protector attached to a pedestal typically addresses a maybe microsecond and thousands amp transient. These anomalies are rare (maybe once every so many years depending on geographic and geological conditions) and potentially destructive to everything inside an RV. Three completely different surges addressed by three different protectors.

Device b) addresses a common problem that is a threat mostly to motorized appliances (air conditioner, refrigerator).

[Raugustin]

Hi Westom,

a)Current is something that is drawn through the breaker from the load, it is not a surge. A surge is typically a spike on the sinusoidal waveform and is usually a result of transient switching of reactive loads or other anomalies on the line. When we talk about burn-outs of motors, specifically compressors, we talk about the effects of current and surges. Voltage surges caused by reactive loads being switched or transients will pass through a breakers and will weaken the insulation of motor windings...it may take many incident and may not effect the motors right away but they will, in time, effect the insulation of the windings. You may also have a catastrophic surge or spike created by lightning or a utility failure that could damage the units in a single event, however those are very rare. When voltage is reduce for a significant time in an induction motor, the current will increase and the slippage will also increase resulting in reduced speed and a significant increase in heat and the compressors in both the refrigerator and AC will rely on their internal thermal protection which is designed to shut down the motors when this happens. The increased current could also trip the dedicated breakers before the thermal protection is activated, breaker usually trip very quickly, a few milliseconds once the threshold is reached. So there is already protection provided for under-voltage and short circuit conditions and inadvertently, yes, circuit breakers and current have played a significant, but maybe indirect, part in this conversation.

b)If your voltage does not dip below 95V, as you indicated, then you are relying on the internal thermal protection of the compressors or the dedicated circuit breaker and the installed protection device will not help until conditions meet or exceed its threshold voltage. You could have a sustained under voltage whereby your protection is not effective, and under voltage of 5% use to be a concern but in the last decade the standards have been desensitized, due to excessive loading of the grid and reduction in generators, to be between 5 to 10 %.

C) Metal Oxide Varistors (MOV) have been used for many decades to protect circuits against excessive transients or voltage spikes. I am not saying that they are the be-all and end-all for protection. But the are found in most if not all surge suppressors used today and you will find them in the protective devices that have been discussed in this forum. They can be purchased independently and installed for penny's and will provide protection against voltage spikes and catastrophic transients. The only problem is they may wear out over time and you will not have any indication that they are not working. They will also not protect against open neutrals and sustain over-voltage...but are certainly better than nothing and are very cheap and can be replaced annually.

D) I also mentioned the 80% factor and protection that is already built into ever electrical component today through the different codes/standards and regulations in North America. Someone said, in a posting, that the wanted to make sure that their main cable was protected. Knowing that it is rated at 125% of it's maximum current and is tested at voltages far in excess to what you will experience should buy some comfort level, it should not be a deal breaker for internal vs external protective devices.

Don't get me wrong, I am in favor of more protection but we should be able to check the power at a pedestal to ensure that the neutrals and grounds are connected and that the voltage is correct before we simply plug in the trailer, some due diligence is required on our part even if you have the extra protection. Secondly, your trailer already comes with protection for many of the problems you'll encounter and many more can be addressed with a simple multi-meter before you connect and for those that don't want to spend an additional $300 - $500 adding simple MOV's may be an option for them.
Ron

[clubhouse]

Raugustin,

Let me in on the secret on how you are using and installing, even suggesting, MOV discrete components to provide home made protection?

I have an electronics background, spent 10 years selling semiconductors (both IC and discrete components) so I am familiar with MOV (and other TVS type components) and what they do. Are you suggesting someone gets MOVs in a axial package of some type, cut into there power supply somewhere near the converter and solder them in place? Discrete components operate on DC power...we are plugging our TT into AC power, which means that a someone has to be sophisticated enough to create AC - DC converter, add the MOV, the convert it back so that the down stream components AC-DC convertors get the correct current type. That seems like a recipe for disaster and not really relevant to the average RV user.

[David472]

Raugustin, very well said.
Clubhouse, if a person has sufficient working knowledge of electrical-electronic circuits, installing MOV's is a snap. They install on the AC power feed, at a convenient screw terminal on that feed. On the axial leads of the MOV, crimp and solder a spade connector to each of the two leads which will then slide into the screw terminals. Install one each between live and neutral, live and ground, and neutral and ground. Three in total for a 120 VAC feed. The choice then becomes which part number of MOV to select. Number V130LA20 would be a good place to start.

[clubhouse]

Originally Posted by David472

Raugustin, very well said.
Clubhouse, if a person has sufficient working knowledge of electrical-electronic circuits, installing MOV's is a snap. They install on the AC power feed, at a convenient screw terminal on that feed. On the axial leads of the MOV, crimp and solder a spade connector to each of the two leads which will then slide into the screw terminals. Install one each between live and neutral, live and ground, and neutral and ground. Three in total for a 120 VAC feed. The choice then becomes which part number of MOV to select. Number V130LA20 would be a good place to start.

Thank you for the information. Although I have and am happy with my SurgeGuard 30A portable EMS...I'll admit am curious about adding MOVs. Next time I am at the TT I am going to take a look to see if I can locate the screw terminals you mentioned. Again, thank you.

[Raugustin]

Hi clubhouse,

I also have an electronic/Industrial Instrumentation background and hold 2 Electrical (Red seal) licenses and a Master electrical license...I am not saying that everyone should do this...it can be an option for some....a description has already been posted in many forums which describes the process and identifies the components. As David indicated it is very easy for those with some technical know how and from what I see on this forum many people have the capability. The confusion that is happening is the name used as "surge protector" the device most people are referencing has more capabilities than surge suppression, it also protects against under/over voltage, checks that the wiring configuration/potential of the supply is correct, its resettable and has indicators that identify problems. IMHO I think they are far to expensive...duplicate safeties that are already in your trailers components and are not necessary. True surge suppression, however, is...even though it is a rare anomaly. Many failures to AC and refrigeration units are not the result of under voltage...the internal thermal protection already safeguards that equipment from this...it usually results from poor workmanship or operation. I have attached a posting below from another forum that shows how a home made surge suppressor is made including component numbers, David has also indicated an MOV that is useable. I'm sorry that the pictures did not copy over but basically the MOV's where positioned across the live-to-neutral, live-to-ground & neutral-to-ground. It's very simple and if you open the moderately priced or inexpensive units you will more than likely find a similar setup for surge suppression.
Regards,

Ron


Posted 24 July 2010 - 10:58 AM
I have been meaning to purchase a power line surge protector for our Casita. I am not the type that would dream of plugging a TV or home stereo system into a home plug without some sort of surge protector, but here I am three years into this new camper without any surge protection. Just think what a high voltage spike could damage: converter, refrigerator, AC, sound system etc. Enough to really ruin a trip!

What I wasn't prepared for was the cost of commercial surge suppressors for campers/RVs. It appears that a simple inline protector starts at about $80. Hard wired units that protect against low voltage or power line frequency problems quickly cross $300. These may well be worth the money for peace of mind, but I just want basic protection from over-voltage spikes. Three MOVs (Metal Oxide Varistors), a plug, socket and short section of chord shouldn't cost $80. I went to the shop and found the parts left over from past projects, but since I assume most readers of this Forum are not ham operators and pack rats, I tried to track down a source for these items.

Parts list:

Radio Shack MOVs (part 276-568) about $2 each X3
30 Amp 3 prong female receptacle (Camco) about $6 any RV store
Short 30 amp male molded plug/chord about $10 any RV store

Attached Image: KAMCO parts (Small).JPG


Male Plug and chord and Female receptacle


Attached Image: MOVs (Small).JPG


The three MOVs are mounted across the hot and neutral wire, The hot and ground terminal, and the neutral and ground terminal. All three are needed to protect against common mode spikes (typical of nearby lightning strikes). The Camco receptacle has enough room to hold all three MOVs without any modification.

Attached Image: Labled receptecal (Small).JPG


Finished labeled project


Why would you not want to do this? There is no liability or damage insurance that is typical of commercial products



I got the CAMCO receptical from Dixie RV in Newport News, VA. It was some years ago for a project I never completed so I guess prices have gone up (high price of plastic I guess).

You could do the same project with a short 30 amp extension cable and a simple 110 volt electrical junction box in the middle. Cut the cable in the middle and mount the MOV's in the box. I was just using what I had on hand.

Not much at drawing schematics, but I copied the installation diagram from the CAMCO unit.

In a perfect world, two MOVs would be enough, but is either the neutral or the ground lead are not functioning, a common mode spike could cause damage.

Attached Image: MOV Placement (Small).jpg

Originally Posted by clubhouse

Raugustin,

Let me in on the secret on how you are using and installing, even suggesting, MOV discrete components to provide home made protection?

I have an electronics background, spent 10 years selling semiconductors (both IC and discrete components) so I am familiar with MOV (and other TVS type components) and what they do. Are you suggesting someone gets MOVs in a axial package of some type, cut into there power supply somewhere near the converter and solder them in place? Discrete components operate on DC power...we are plugging our TT into AC power, which means that a someone has to be sophisticated enough to create AC - DC converter, add the MOV, the convert it back so that the down stream components AC-DC convertors get the correct current type. That seems like a recipe for disaster and not really relevant to the average RV user.

[clubhouse]

What can I say, I am simply impressed with the knowledge shared in this thead. To bad in a few weeks it will be buried and likely won't be found by others searching Electrical Managment and Surge Protection because we took this discussion so far off course from the OPs intent and title. :-)

[westom]

Originally Posted by Raugustin

a)Current is something that is drawn through the breaker from the load, it is not a surge. A surge is typically a spike on the sinusoidal waveform and is usually a result of transient switching of reactive loads or other anomalies on the line. When we talk about burn-outs of motors, specifically compressors, we talk about the effects of current and surges. Voltage surges caused by reactive loads being switched or transients will pass through a breakers and will weaken the insulation of motor windings...it may take many incident and may not effect the motors right away but they will, in time, effect the insulation of the windings. You may also have a catastrophic surge or spike created by lightning or a utility failure that could damage the units in a single event, however those are very rare. When voltage is reduce for a significant time in an induction motor, the current will increase and the slippage will also increase resulting in reduced speed and a significant increase in heat and the compressors in both the refrigerator and AC will rely on their internal thermal protection which is designed to shut down the motors when this happens. The increased current could also trip the dedicated breakers before the thermal protection is activated, breaker usually trip very quickly, a few milliseconds once the threshold is reached. So there is already protection provided for under-voltage and short circuit conditions and inadvertently, yes, circuit breakers and current have played a significant, but maybe indirect, part in this conversation.

The term 'surge' has a defintion so varied that no more than two posters are using the same defintiion. For example, a highly regarded professional on this subject says: "The IEEE ... has adotped a wored surge to denote an overstress condition that has a duration of less than a few milliseconds". So even the Progressive that takes far longer to respond is not doing surge protecton.

Your computer declares a surge when a USB device draws too much current. Some motherboards declare a surge when its motherboard voltage varies too much while the computer continues working normally. Which 'surge' is everyone discussing?

Numerous anomalies exist including frequency variation, harmonics, EMC/EMI, compromised neutral, voltage variations, floating ground, sags, brownouts, RFI, etc. Even a sag and brownout are different anomalies.

Which ones are harmful? Nobody can say without numbers. Subjective claims are why both scams and contradictory claims exist. 'Surge' is so easily and intentionally subverted to even get the naive to promote myths.

MOVs are cited as a solution without first defining what the MOV actually does. In some devices, MOVs only protect from transients that typically cause no damage. In another device, MOVs work by connecting that anomaly to something completely different that does the protection. We know this. MOVs only degrade when grossly undersized. When used in situations that even violate specification numbers in MOV manufacturer datasheets.

A Progressive addresses one anomaly. A protector at the pedestal is for another and different anomaly that might even damage the Progressive. Which device is needed? First the anomaly must be defined by numbers. Including size of and frequency of each anomaly. The Progressive is for an anomaly too often found in campgrounds. And rarely seen in homes.

Some motors have that internal protection. Others do not. Utilities either provide voltage within a narrow range. Or disconnect power. To maintain voltage that might otherwise harm electric motors. Campgrounds sometimes do not do that (and may not even understand the problem). One reason why many use a Progressive to protect from a surge that really is not a surge.

[llerberg]

Just remember, if you have one stolen think long and hard about turning in a small claim to your insurance as they will likely raise your rates and it will cost you more than the loss was in the first place

[StringFellow]

Here is a simple solution to lock your surge protector and prevent theft.

Parts needed:

2 pad locks (keyed the same for connivence)
2 1 foot sections of heavy duty chain.

Step 1: Install one pad lock around the cable on the input side of the surge protector. Install it around the wire between female plug and surge protector control "box". Before locking pad lock connect chain and lock it. You can leave this lock always locked and attached to surge protector. If there is room on the pad lock shack, install additional section of chain for additional protection..

Step 2: Install second pad lock around the wire of your rv power cable. Before locking attach chain (choose the link in the chain with the least amount of slack) connected to pad lock in step 1.

This will allow someone to unplug the surge protector from your rv power cable but chains will prevent removal. The power plugs (male and female) prevent the pad locks from being slide off the wire. Pad locks need to be as small as possible yet can wrap around the wires and with enough height in the pad lock shank to connect the chains.

Theft would only be possible with a large set of bolt cutters. If someone has bolt cutters in a camp ground they will be interested in stealing more than a surge protector. I.e copper present in your rv power cable.

[neverenoftackle]

Hey StringFellow thank you for that,
I had already figured out using a chain from the SP to the post. As you said one lock tight to the wire between the plug and the the SP box/ with in the lock. The next wraped tight and locked to post. All keyed alike. I never visioned a short chain from SP to the RV's plug with locks.