Transient Voltage Spike Protection Home Made Device

My Progessive unit also protects the electric units from low voltage which will burn out any appliance if left on with low voltage. So I have high and low and miswired connection protection. Some things are worth the cost.

Ava wrote:
My Progessive unit also protects the electric units from low voltage which will burn out any appliance if left on with low voltage. So I have high and low and miswired connection protection. Some things are worth the cost.

What he said.. :)

Perhaps I'm not so smart - BUT....I bought a progressive, installed it myself and it has saved every electrical thing in the rig - TWICE!!
I consider it an EXCELLENT investment!!

MEXICOWANDERER wrote:
I'm stubborn. When I found out how stupidly expensive adequate "Surge Protectors" cost, I hit the roof. Screw that. I ordered the components.

Designed for 180 volt peak-to-peak protection ((the standard down here is 127vac 60Hz.)

20 mm Metal Oxide Varistors
10 mm Metal Oxide Varistors (10 volts higher rating)
Transient Voltage Surge Protection bi-directional diodes 4ns reaction time
Gas Discharge Tube devices

L1-L0
L1-Earth Ground
LO-Earth Ground

(8) MOVS
(4) TVS
(2) GDT

I'll see about sending some images to NinerBikes.

If you can do basic soldering, you can do your own and end up with genuine protection and not a vastly overpriced fraud.

BTW: A fully functional grounded isolation transformer is 100,000 times better than my gizmo.

Mex,

I am not sure what you are looking at that is so expensive..

The parts you listed plus RFI/EMF suppression (IE RF choke/capacitive network), on/off switch AND a 12A-15A breaker are typically included in good brands of computer type surge protector/outlets.. Additionally good quality surge protectors will also have the surge (MOV and bidirectional diodes FUSED, when the diodes blow, the fuse opens and the surge protection fault indicator light will show that you no longer have surge protection..

You can get a Panamax protector for $33 HERE

APC makes a good one for $33 HERE

by the time you buy ALL of the parts PLUS outlets, pigtail wire and a pretty box to put it all in AND your time (my labor isn't cheap) you could have bought a ready made unit..

If you don't want RFI suppression you can get surge protection only for $8.99 which would have MOVs but not the diodes HERE

I would definitely not recommend using those bare parts without adding a fuse in series with the protection.. I HAVE seen those bidirectional diodes SHORT and if you don't fuse those things you will end up with more fireworks than the Fourth of July.. :E

Not a place to "cut corners"..

Hi Gde,

Do the ones you listed handle 30 amps and/or 50 amps?

Gdetrailer wrote:

I am not sure what you are looking at that is so expensive..

The parts you listed plus RFI/EMF suppression (IE RF choke/capacitive network), on/off switch AND a 12A-15A breaker are typically included in good brands of computer type surge protector/outlets.. Additionally good quality surge protectors will also have the surge (MOV and bidirectional diodes FUSED, when the diodes blow, the fuse opens and the surge protection fault indicator light will show that you no longer have surge protection..

You can get a Panamax protector for $33 HERE

APC makes a good one for $33 HERE

by the time you buy ALL of the parts PLUS outlets, pigtail wire and a pretty box to put it all in AND your time (my labor isn't cheap) you could have bought a ready made unit..

If you don't want RFI suppression you can get surge protection only for $8.99 which would have MOVs but not the diodes HERE

I would definitely not recommend using those bare parts without adding a fuse in series with the protection.. I HAVE seen those bidirectional diodes SHORT and if you don't fuse those things you will end up with more fireworks than the Fourth of July.. :E

Not a place to "cut corners"..

My opinion is that 104 volts cut out is about 3 volts too low. I.E. it should cut out at 107 volts, not 104.

Since I'm far more likely to find low voltage, an autoformer would be much better for me--with Mex's surge device between the autoformer and the pedestal.

Ava wrote:
My Progessive unit also protects the electric units from low voltage which will burn out any appliance if left on with low voltage. So I have high and low and miswired connection protection. Some things are worth the cost.

My unit has individual fuses*. Expensive high surge capable fuses.
My unit has QUADRUPLE MOVs backup. MOVs degrade and fail
I do NOT use 300 volt TVS diodes as they are USELESS. Double diode backups.
The Gas Tube Discharge Devices are lightning protection
Now do these Super Whammy thirty dollar specials use 20 mm MOVs? Hell no they don't. Try 10 mm.

Typical worn-out "surge protector" Typical empty fire extinguisher. Same protection.

Not born yesterday, kind sir. Born day before.

*Honorable GDT devices NOT FUSED. They are closest to the connectors to act as an ionization path for lightning. Do honorable garbage surge protectors have individual GDT devices from line to neutral and line to earth ground?

Why did I choose ONE DOLLAR EACH FUSES? Because they can absorb 5+ amperes for many milliseconds, right up to the limit of the TVS diode carry. TVS diodes usually fail shorted, MOVs usually fail open circuit. Would love to see a GDT device fail shorted.

I DO NOT LIKE LIGHTNING. I have seen first-hand what it can do. That's why I returned to Stanford and took a 10 day course from professor I. Ickles PhD who did his best to translate functionality of a lightning strike into meaningful terminology and mechanical functionality. Lightning is by far best handled as far away from service as a person can get it - but when push comes to shove a GDT serves as an ionization leader hopefully directing a strike out of the rig and utterly destroying everything in it's path on it's way up to the clouds. Ionization. The diodes take the brunt then the MOVs a few microseconds later. The GDT buys more time. Perhaps enough for the leader to establish a firm route. It's ugly. But it's better than allowing a leader to run amok. I've seen mobile homes with outside paneling peeled away from the frame. Melted. A huge fire usually ensues and it instantly involves the entire rig.

As pitiful as it may be, some form of diversion at the entrance panel is a hell of a lot better than buffalo chip MOVs and one or two TVSs.

Meanwhile institute a search for American-quarter size MOVs in one of those thirty dollar "surge protectors".

I tore into a FIFTY DOLLAR BELKIN surge protector a few months ago and found ZERO TVS diodes, no GDT protection and dime size MOVs. Yes, there are expensive ISOBAR Tripplite protectors, that probably have all three devices and a hundred dollar price tag and a disturbing inability to fit inside an RV main breaker box.

AND FOR GOD'S SAKE (some) PEOPLE, I beg you to LEARN the difference between voltage protection correctors, disconnects, and transient voltage protectors. This is an apples and Steinway piano comparison. Something that protects when voltage goes low may be the worst transient voltage protection (zero). A low voltage correction device does exactly that. I would LOVE to see one with MOVs, TVS, and GDT protection.

A TRUE protection system like I have at home is hideously expensive. A 5KW Sola ferroresonant line tamer with 6,000 watt isolation transformer costs about eleven thousand dollars. Mine is rated -40% - +40% 168 volts down to 72 vac, the unit outputs 120.0 volts exactly. No steps. Smooth as a baby's rear. The Triad Sola isolation transformer removes ALL harmonic distortion, and transient voltage events.

But it ain't free. That eleven thousand dollar three hundred+ pound monster eats 132 watts doing absolutely nothing. I made a knife switch, dual pole out of copper straps. When a thunderstorm threatens which is often the switch is opened. Exactly .060" from the shore power inlet (right from the service drop) are a pair of aluminum 1" rods, driven three feet into the soil. My discharge device protection. The knife switch is overhead to protect little fingers from having shortened lives. The shed door of K Monel is kept locked. I do not have fourteen thousand dollars to invest in another Tektronix scope. That room must have 20-30K worth of electronics, and it isn't all going to die by electrocution.

I'm going to try and cram the transient voltage protection board inside the BORG. Three thousand miles is a long way to drive for a replacement Megawatt.

Just for information - I use a Mexican made automatic 20% booster on the A/C and room interior (lights, receptacles). Then a 1,200 watt isolation transformer. When Frankenstein is in the lab the Sola and Triad get switched on.

I have another booster and another transformer protecting the three freezers and Viking. I purchased a PALLET of (48) isolation transformers from HALTEK Electronics in Rhonert Park. 2,300 lbs worth. Let's Make A Deal cost me 260 dollars. NOS.

But thanks for the head's up about the TVS. When a person buys four nanosecond response time, something has to be given up.

I put MOV's in Mom & Dad's panel box over 30 yrs ago. They were always have internal fuse's popping in microwaves and TV's in the hills of KY. I just fastened them into the circuit breaker and ground. Every now and then one would pop and trip the circuit breaker and I would replace it on my next visit. It seemed to reduce the frequency of problems. Whole house protection with a handful of blister packs.

Yep. Those "Soooooooge Protector" manufacturers have to have UL or ETL device certification. Try $50,000 + for the cert. THEN

They have to carry million dollar product liability insurance.

I do not feel like feeding the yacht sailing Yuppie executives at Underwriters Laboratories, or some chauffered limousine Wall Street insurance firm. Paying forty dollars for six dollars worth of parts ain't my bag.

Power strip "sooooooge protectors" are not fixable. Damned lucky to find one with 14 gauge wire. I have opened up too many and damaged a rib laughing myself sick.

With paralleled 20 mm MOVS their failure rate goes way down. With paralleled TVS diodes let's find out using reality if the bi-directional diodes "current hog". If transient positive and PIV spikes manage to overcome my authentic spike protection device they are going to have to work at it.

Should be able to tell from nearby curses and screams if a really bad series of events has hit line voltage.

Pianotuna and NinerBikes get theirs just as soon as I get access to the USPS. Yes and all but the Gas Discharge Tube devices have fuses. Fusing a device filled with gas and no conductor route would be an amateur's mistake.

Pianotuna writes “Hi Gde,

Do the ones you listed handle 30 amps and/or 50 amps?”


“Technically” in a “round about way” YES.

But not the way you would think of..

You are thinking of an external mystery box that you plug your RV into via the shore cord..

The devices I listed are power/surge strips in which you typically plug individual items into.. But the “protection” they offer actually EXTENDS to EVERYTHING on that power circuit provided the power strip is plugged into an outlet AND turned on AND the protection devices are functioning..

The devices which Mex mentioned are placed in PARALLEL to the “circuit” or power lines if you like.. They are not “In series” and therefore ALL the protection is available BEFORE AND AFTER where the protection devices are inserted into the circuit.

They work by SHUNTING voltages that exceed their breakdown voltage threshold TO GROUND, is also known as “clamping”.

To be very clear, NO “surge protection devices” can or will protect against a DIRECT LIGHTNING STRIKE even several miles down the power line!!! They only protect from lightning INDUCED surges (indirect lightning strikes)..

I am not aware of any device that would be reasonably priced that would handle a direct lightning strike, therefore the “best practice” of preventing damage during a strong thunderstorm is to physically disconnect your electronic devices from the power company (IE unplug shore power or TVs/entertainment items)..

A good explanation of MOVs can be found HERE

From the website above..

“The Metal Oxide Varistor or MOV is a voltage dependent, nonlinear device that provides excellent transient voltage suppression. The Metal Oxide Varistor is designed to protect various types of electronic devices and semiconductor elements from switching and induced lightning surges.

When exposed to high transient voltage, the MOV clamps voltage to a safe level. A metal oxide varistor absorbs potentially destructive energy and dissipates it as heat, thus protecting vulnerable circuit components and preventing system damage. Varistors can absorb part of a surge.
About the MOV – Metal Oxide Varistors

A MOV contains a ceramic mass of zinc oxide grains, in a matrix of other metal oxides (such as small amounts of bismuth, cobalt, manganese) sandwiched between two metal plates (the electrodes).

They can be connected in parallel for increased energy-handling capabilities.
MOVs can also be connected in series to provide higher voltage ratings or to provide voltage rating between the standard increments.

A Metal Oxide Varistor remains non-conductive as a shunt mode device during normal operation when voltage remains well below its “clamping voltage”. If a transient pulse (often measured in joules) is too high, the device may melt, burn, vaporize, or otherwise be damaged or destroyed.”

Typical simple in circuit usage (symbol with SIOV)..


Picture of MOV


Transit voltage bidirectional diodes and gas discharge tubes are also placed in parallel just the same as MOVs, they work similar to MOVs but with different speeds.

Cheap surge protection power strips ($8.99) typically only have MOVs and the more expensive versions ($30 and up) will have MOVs, Bidirectional diodes and gas discharge tubes.

When dealing with a 50A RV shore cord you simply need two surge strips and make sure that one of each is connected to L1 and L2..

One of the reasons as to why those external 30A and 50A “surge protectors” cost so much is the fact they ARE designed for the RV “industry” and they often offer other “protection” like OVER and UNDER voltage disconnect and or AVR (Automatic Voltage Regulation)..

To be clear Mexs idea does not address OVER/UNDER voltage nor does it address AVR..

If you dig around, you can find plug in surge/power strips which do have over/under voltage disconnect protection and if you want AVR many good UPS units actually provide surge AND AVR functions.. Just beware with these you must plug in items to be protected downstream to get the “protection”..

An additional way to add “surge protection” is to install a “whole house” surge protector in your RV breaker panel..

You can get a Leviton 51110-SRG Residential Surge protection Panel for as little as $43 from HERE

Looks like



Typical home installation requires the use of two 120V single pole breakers that go to the device.. In a RV you would need only one single pole 20A breaker for a 30A shore power connection and only need to wire L1 or L2 of the protector.. Or if no extra breaker spaces available you could simply wire to any of the breaker protected branch circuits in a pinch.

You can view the installation manual for the Leviton protector

HERE