Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Dirty power "Filter"

Options
kcopp
kcopp Member Posts: 4,448
Some emergency power generators emit a less that great power supply w/ a hertz rating that will mess up some more sophisticated boiler controls. What UPC can you wire in line to clean up the power supply to allow the boiler to run w/o issue?
ty,kcopp

Comments

  • Jamie Hall
    Jamie Hall Member Posts: 23,657
    edited November 2016
    Options
    There are any number of true sine wave UPS systems -- Tripplite, APC to name two manufacturers. Being UPS units, they give you a little time to hustle out into the blizzard to start the generator.

    They are also expensive. The price you pay for fancy electronic controls on the boiler...

    If you don't need the UPS function, there are also power supply filters made for high end high fidelity equipment which can also tidy things up. They are also expensive...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    kcopp
  • ChrisJ
    ChrisJ Member Posts: 15,923
    Options

    There are any number of true sine wave UPS systems -- Tripplite, APC to name two manufacturers. Being UPS units, they give you a little time to hustle out into the blizzard to start the generator.

    They are also expensive. The price you pay for fancy electronic controls on the boiler...

    If you don't need the UPS function, there are also power supply filters made for high end high fidelity equipment which can also tidy things up. They are also expensive...


    This was something I always got a good laugh out of, also had many arguments over it over years.

    Cleaning up AC power for equipment that runs on DC.
    I don't know about anyone else, but all of the audio equipment I've restored, and the stuff I've designed my self all couldn't care less what went in the AC mains input as long as it was alternating and around 100-130 volts. Square wave, sine wave, didn't matter because it was rectified and very well filtered. Or, in the case of some of the stuff I built, even regulated.

    But yeah, HUGE market for ripping audiophiles off. That and special "directional" wires and moon rocks. It goes on and on and on.


    When it comes to boiler controls, I don't know which ones wouldn't tolerate the lousy output from cheap generators, but I do know some equipment does genuinely complain. My stuff doesn't care luckily.

    Jamie, do you know if it's reasonable to assume one could take a fairly small UPS and connect it to a large deep cycle lead acid battery to extend run times?
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • BobC
    BobC Member Posts: 5,481
    Options
    Buy garbage, get garbage. If someone buys a generator on price alone without knowing what the specs are they deserve what they get.

    You could try running the output of the generator through a large isolation transformer, the inductance might help. A variac would probably help because a rectifier only cares about the peak voltage so you could boost the voltage a bit to see if you can get the resulting dc voltage high enough so the regulator in the boilers electronics can do it's job.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • kcopp
    kcopp Member Posts: 4,448
    edited November 2016
    Options
    The unit in question Laars Endurance... Not sure of the brand generator but it is supposed to be a reputable unit. It is wired into the home through a transfer switch.
    Runs fine on regular power but when transferred to the generator after an hour it quits.
  • ChrisJ
    ChrisJ Member Posts: 15,923
    Options
    BobC said:

    Buy garbage, get garbage. If someone buys a generator on price alone without knowing what the specs are they deserve what they get.

    You could try running the output of the generator through a large isolation transformer, the inductance might help. A variac would probably help because a rectifier only cares about the peak voltage so you could boost the voltage a bit to see if you can get the resulting dc voltage high enough so the regulator in the boilers electronics can do it's job.

    Bob

    Might have to be careful with that depending on the generator.

    My early 90s Coleman outputs 130Vac or so unloaded and around 128Vac fully loaded @ 60Hz. This is one of the reasons I always connect it using 100ft extension cords.

    So far nothing has ever had an issue running on it though. I've considered dropping the RPMs some as I doubt anything I own cares about 60Hz. Would likely be just as happy running at 50Hz.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • Jamie Hall
    Jamie Hall Member Posts: 23,657
    Options
    I didn't say I recommended using the high end audio power filters! If the amps (particularly preamps) are properly designed and shielded, you can run them on square waves at more or less the right frequency and it makes no difference at all. But the filters do exist, and they are sold to the golden eared types. Along with monster cables all gold plate and such like extravagances!

    I have an ancient Craftsman generator. Noisy. Not efficient. Hates 10% ethanol gas. But it generates something close to a sine wave at 61 hz, and everything works just fine, thank you -- except the older electric clocks and one of my high fidelity turntables (synchronous motor), which runs fast and sharp, and yes I can hear the difference.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    ChrisJ
  • ChrisJ
    ChrisJ Member Posts: 15,923
    Options
    @Jamie Hall
    I assume mine doesn't produce clean output, but I've never put a scope on it I don't think. If I did, I don't remember doing it.

    https://youtu.be/6diY0EG32wM

    https://youtu.be/Mz3-eE5pWQ8



    Those videos are from earlier this year when I pulled it out to exercise it some. Still considering converting it to natural gas, but I'm not sure how good the conversion kits I see really are. For $150 +- they just seem too good to be true.

    One place even has a picture of their kit installed on the engine I have.


    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • BobC
    BobC Member Posts: 5,481
    edited November 2016
    Options
    What I'm implying is if you don't know what the output of generator is your buying a pig in a poke. Generators that supply a decent sine wave cost more but they will usually power anything withing
    their power range. Maybe the generator needs work?

    If the boiler runs for an hour and then quits something is drifting. Put a decent meter on it (true RMS if possible) and see what the output is initially and then after an hours. I would also measure the frequency if I could. If you really want to know whats going on, looking at the output with a scope would tell the story.

    i suspect the regulators in the boiler electronics are dropping out and that is putting crap on the internal DC buss and that is driving it nuts.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
    kcoppSWEI
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,853
    Options
    I paid $50 for a APC UPS from Best Buy for the PC's I have in the mountain home which gets surges etc. Was told by my PC expert that they make great filters/surge supressors. Really not looking to carry the loads for long periods of time as much as I am trying to stop surges from taking out my electronics. Lightning strikes are very common. I don't remember the KWH capacity. PC's are programmed to reboot on power up, so not worried about carrying capacity. I lost about $500 worth of electronics from a lightning strike this summer.... Saw it hit the pole, and felt the heat. Scary stuff.

    ME

    There was an error rendering this rich post.

    kcopp
  • ChrisJ
    ChrisJ Member Posts: 15,923
    edited November 2016
    Options
    I have to be honest.

    All quality PC power supplies already have plenty of good MOVs in them so I've never worried about it and have never even considered needing a good "surge protector, aka wallet emptier" on any of my PCs.

    There's not a single device you can buy that's going to protect against a lightning strike. 1 to 100 Terawatts?
    I want to see the MOV, or array of MOVs that can shunt that.

    You're talking 1,000,000,000,000VA minimum. It's not happening and no fuse or breaker will react fast enough nor will have a large enough gap to stop it anyway. If your line gets hit by lightning, everything on it is toast. 1,000,000+ volts will jump across a circuit breaker or fuse like it's not even there.



    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • Harvey Ramer
    Harvey Ramer Member Posts: 2,261
    Options
    There are lightening protectors that work, to some degree anyway. The current is faced with jumping a point and going directly to ground, or staying in the conducter and traveling through a heavy coil. The coil typically has enough resistance to make the lighting surge jump the points and go to ground, but not enough to impede the flow of normal current. This of course provides protection only against extremely high voltages. A standard surge suppressor is still needed for lower level surges.
    ChrisJ
  • BobC
    BobC Member Posts: 5,481
    Options
    It depends on the length of the line between your house and the strike. That length is an inductor at these risetimes and that inductor coupled with a really good whole house surge device can save you. The really good ones have a hocky puck sized MOV and points that will flash over if it gets hit with a real blast.

    If the strike is right next to the house your toast but you'll be too busy changing your shorts to really care.

    A coworker of mine lost a lot of his appliances when a 12kv line dropped across the 120 / 240 line on the next block because the power company screwed up. A guy across the street heard a load pop and found the 60a breaker and his 100a house main breaker tripped. When he reset them all was well. That little mishap cost the local power company big time.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
    ChrisJ
  • adambnyc
    adambnyc Member Posts: 260
    Options
    @ChrisJ I did the Trifuel conversion to my 7K BnS genny, works great! Of course, I invested all that money in the generator, conversion kit and piping and I've never used it a single time in 5 years or in any emergency at all, but that's another story all together.

    I keep a pure sine wave UPS in my house. I have a few of em for various computer related reasons. I never tested it, but I'm really curious how long my boiler could run on a completely charged UPS.

    I also pondered the generator clean power issue to electronics. I got up to the point where I realized that a UPS is also a "sensitive electronic device" and might need a sine wave itself to recharge. I'm gonna test charging my UPS with my generator when I get around to kicking it over, but I would not be surprised if the UPS didn't charge, or at worst actually fried.
    ChrisJ
  • kcopp
    kcopp Member Posts: 4,448
    Options
    I'm hoping that just running the boiler through the UPS will allow the system to work. I have them asking for the generator to be tested.
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,853
    Options
    ChrisJ said:

    I have to be honest.

    All quality PC power supplies already have plenty of good MOVs in them so I've never worried about it and have never even considered needing a good "surge protector, aka wallet emptier" on any of my PCs.

    There's not a single device you can buy that's going to protect against a lightning strike. 1 to 100 Terawatts?
    I want to see the MOV, or array of MOVs that can shunt that.

    You're talking 1,000,000,000,000VA minimum. It's not happening and no fuse or breaker will react fast enough nor will have a large enough gap to stop it anyway. If your line gets hit by lightning, everything on it is toast. 1,000,000+ volts will jump across a circuit breaker or fuse like it's not even there.



    Chris, I will defer to your knowledge base. I can say tho, that the PC's (3 of them) all survived the strike. It was my low voltage controls (ENV) that took the hits and scrambled their little brains. They are now powered through the APC.

    I really don't think anyone understands lightning completely. Even the lightning labs are constantly finding new variables that they didn't know existed. I rolled the dice ($100 spent) to see if it could save me $500. May lose, may win, may never really know.

    BTW, the strike hit a power pole/transformer 2 houses away from mine, and I happened to be looking at it when it hit. Felt the heat from about 150 feet away. Glad I was using cordless tools at the time... When the power company showed up, the static line fuse to the transformer was vaporized. It took out a $2,000 oven in the house next to the pole.transformer. Awesome power there...

    ME

    There was an error rendering this rich post.

  • ChrisJ
    ChrisJ Member Posts: 15,923
    edited November 2016
    Options
    adambnyc said:
    Anyone else notice there's a screw missing in the picture of the back of the unit? :)

    On a serious note tho, why can't I find any actual energy ratings on these? 1500VA, ok, how about volt amp hours or watt hours, something.

    I'm curious how long one could run my boiler for consuming 12 watts or so. I'm thinking 4-5 hours worth of actual run time.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • Jamie Hall
    Jamie Hall Member Posts: 23,657
    edited November 2016
    Options
    The volt ampere rating is an energy rating, not a power rating. It gives you the product of the volts delivered times the amps delivered until the battery is flat. Thus 12 watts... if that's 120 volts, that's a tenth of an ampere. So for 1500 volt amperes, that would be a grand total of 13 amperes. If you are drawing a tenth of an amp you could do that for 130 hours. If my math is right...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • ChrisJ
    ChrisJ Member Posts: 15,923
    edited November 2016
    Options

    The volt ampere rating is an energy rating, not a power rating. It gives you the product of the volts delivered times the amps delivered until the battery is flat. Thus 12 watts... if that's 120 volts, that's a tenth of an ampere. So for 1500 volt amperes, that would be a grand total of 13 amperes. If you are drawing a tenth of an amp you could do that for 130 hours. If my math is right...

    Since when is volt-amps an energy rating? I'm confused :)
    It's no different than watts, other than it indicates apparent power in AC circuits. No?

    Ah would be an energy rating because it includes time. VA alone is meaningless.

    I read 1500VA as being it can supply a 1500VA load, but it doesn't say for how long. 10 seconds? 5 seconds?
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • ChrisJ
    ChrisJ Member Posts: 15,923
    edited November 2016
    Options



    Based on this, I would assume it could run my 12W boiler for around 4 hours. But even that seems wrong.




    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • SWEI
    SWEI Member Posts: 7,356
    edited November 2016
    Options
    Surge suppressors work by diverting energy to ground, so a surge suppressor is only as good as its ground. Anything you plug into an outlet is connected to the building ground by its cord, the plug, and the wire that serves the outlet.

    The lowest impedance ground in a building will be at or near the service entrance panel, which also happens to be the most likely point of ingress for unwanted energy. A properly rated SPD installed at the service entrance panel is the best protection you can get once you've verified (and upgraded, if necessary) the grounding electrode system itself.
  • ChrisJ
    ChrisJ Member Posts: 15,923
    edited November 2016
    Options
    SWEI said:

    Surge suppressors work by diverting energy to ground, so a surge suppressor is only as good as its ground. Anything you plug into an outlet is connected to the building ground by its cord, the plug, and the wire that serves the outlet.

    The lowest impedance ground in a building will be at or near the service entrance panel, which also happens to be the most likely point of ingress for unwanted energy. A properly rated SPD installed at the service entrance panel is the best protection you can get once you've verified (and upgraded, if necessary) the grounding electrode system itself.

    Hi SWEI,

    I thought any normal surge would be shunted to neutral, not ground? I wouldn't think any device is legally allowed to intentionally divert current to ground. Just seems dangerous from a safety point of view.

    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • sunlight33
    sunlight33 Member Posts: 378
    Options
    VA is numerically equal to Watt if the power factor is 1.
    ChrisJ
  • BobC
    BobC Member Posts: 5,481
    edited November 2016
    Options
    Most designs have MOV's between hot and ground, neutral and ground and hot to neutral. That tries to clamp any surge to the MOV's rating which is usually 300v.

    We used to test military supplies by discharging a 0.5uf 10,000v cap onto a power supplies input line. The resulting current was enough to fuse the #12 copper wire on the input occasionally.

    The best protection a homeowner can have is a whole house surge protector in the circuit breaker box, it should be mounted right next to the main circuit breaker. The service ground system has to be up to snuff also. This will protect you from most surges but not all.


    UPS run time is proportional to the batteries used. The good ones use 4ea 12v 17AH batteries in series and that kind of UPS is not cheap.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • jumper
    jumper Member Posts: 2,333
    Options
    Some industrial facilities had motor-generators for total isolation. Critical medical facilities should have them but do not. Codes require back up generators for hospitals even when they generate their own electricity. I often think there's a conspiracy to drive me crazy.
    Solid_Fuel_Man
  • SWEI
    SWEI Member Posts: 7,356
    edited November 2016
    Options
    ChrisJ said:

    I thought any normal surge would be shunted to neutral, not ground? I wouldn't think any device is legally allowed to intentionally divert current to ground. Just seems dangerous from a safety point of view.

    If the SPD fires, it's already an out-of bounds condition. @BobC described the typical layout above. Neutral is ground once it hits the main bonding jumper and the intent is to divert as much energy as possible back the earth rather than sending it down the line. The busbar spacing on low voltage (600V or less rated) panels in North America is intended to allow flashover (around 4kV IIRC) as a kind of ultimate fail-safe. An SPD creates a path for lower voltages in order to limit the voltage rise even further.
  • ChrisJ
    ChrisJ Member Posts: 15,923
    edited November 2016
    Options
    SWEI said:

    ChrisJ said:

    I thought any normal surge would be shunted to neutral, not ground? I wouldn't think any device is legally allowed to intentionally divert current to ground. Just seems dangerous from a safety point of view.

    If the SPD fires, it's already an out-of bounds condition. @BobC described the typical layout above. Neutral is ground once it hits the main bonding jumper and the intent is to divert as much energy as possible back the earth rather than sending it down the line. The busbar spacing on low voltage (600V or less rated) panels in North America is intended to allow flashover (around 4kV IIRC) as a kind of ultimate fail-safe. An SPD creates a path for lower voltages in order to limit the voltage rise even further.
    Wouldn't the current be sent up the neutral back to the transformer?
    I thought the ground rod and or water pipe just kept the neutral at the same potential as the earth around the building?

    I see Square D has a QO surge protector, but it takes up two places.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • Fred
    Fred Member Posts: 8,542
    Options
    I think the Neutral from the pole is also jumpered to the Ground bar in the Breaker box.
    kcopp
  • SWEI
    SWEI Member Posts: 7,356
    edited November 2016
    Options
    The grounding electrode system is really there to dissipate dangerous stray currents to earth. There's a grounding electrode at every pole in the distribution system, tied to the PoCo neutral. This network of grounding electrodes references the whole grid to earth. When lightning strikes, the resulting ground wave radiates outward, raising the earth potential (imagine a rock hitting a pond.) Anything even moderately conductive in its path will have an induced current that's trying to find its way back to the earth (actually from, but it's easier to visualize as to.)

    Electricity does not follow the path of least resistance, it follows all available paths in proportion to their resistance (actually impedance, since lightning is really RF energy.) When a lightning strike hits in a spot located opposite the structure from the grounding electrode, some of that energy ends up passing through the building wiring en route to the electrode (since even wet soil is a relatively poor conductor of electricity.) This is why we install ground rods at the bottom of each downconductor in a lightning protection system and tie them together in a ring. That ring protects the wiring and equipment inside it from the ground wave.
    ChrisJ
  • BobC
    BobC Member Posts: 5,481
    Options
    There is a lot of confusion about how much you can get out of a UPS. The quote below gives you a little information about the batteries used in a UPS.

    =======
    Although exact values vary from one manufacturer and battery type to another, the data printed on the battery or on the manufacturer’s spec sheet may look like this:
    Battery type: Sterling H7-12
    12V 7Ah C20 to 1.75V/C, 25C/77F
    Float charge 13.60-13.8VDC; Cycle charge 14.50-14.90VDC; 77F/25C
    12V 7Ah
    12V battery rated for a maximum 7A discharge rate over 1 hour.
    C20 indicates a charge rate of 7A/20 or 0.35A (350ma) is recommended.
    to 1.75VDC indicates the minimum voltage for this battery is 1.75V per cell. This would work out to (1.75x6=) 10.5V for the battery.
    25C/77F indicates that these values are valid for a battery temperature of 25C/77F As the temperature increases above
    25C, the float voltage must be reduced
    Float charge in this case, 13.6-13.8V is the voltage the battery can be indefinitely float-charged at to keep it ready for use.
    Cycle charge the 14.5-14.9V value is the maximum charge voltage, the battery should only be charged for a short time at this voltage.
    77F/25C again, this is the battery temperature that these values are valid.
    This particular battery is a newer design which recommends higher float and cycle charge voltages than most gel cells you
    will find. A more typical recommended float voltage is 13.4 to
    13.5VDC and a maximum charge voltage of 14.1 to 14.4 VDC, also a minimum discharged voltage of 11VDC is more likely. As the battery temperature increases above (in this case) 25C, the float and cycle voltages must be reduced slightly. Likewise,
    as the battery temperature decreases below 25C, these two values can be increased slightly. You will have to refer to the
    manufacturer’s data to find the temperature/voltage curves for your battery.

    ========

    Note you can only use this particular battery from 13.6 down to 10.5v, if you charge it above the recommended charge level or discharge it below the recommended discharge level you are going to shorten it's life considerably.

    This means the usable range of that "12v" battery is only about 3 v, the rest of that voltage is not usable. This is why you really cannot get a lot of power out of a UPS it really is only good for so much before it shuts down on you.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
    ChrisJ
  • SWEI
    SWEI Member Posts: 7,356
    Options
    Single phase service here in North America has two ungrounded current-carrying conductors, so the breaker-style SPD's need two spaces in order to access both busbars in the panel.

    We stock these, which are Type I listed, meaning they can safely and legally be attached to the busbars without a breaker -- we often install them ahead of the main breaker on commercial panels. Most of the QO panels have removable main lugs which we can replace with special stacker lugs to allow this:

    ChrisJ
  • Harvey Ramer
    Harvey Ramer Member Posts: 2,261
    Options
    The sq-d Rep told me their whole house surge protectors absorb the surge and the dissipate it back into the line current.
    SWEI
  • ChrisJ
    ChrisJ Member Posts: 15,923
    Options
    @SWEI I didn't know lightning was oscillating?
    I always assumed it was DC. Not for any reason, really I guess.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • ratio
    ratio Member Posts: 3,701
    Options
    Hehehe! The marketingspeak is strong in that one!

    Reminds me of this. It removes the heatification of the compressifier, or something like that.

  • SWEI
    SWEI Member Posts: 7,356
    edited November 2016
    Options

    The sq-d Rep told me their whole house surge protectors absorb the surge and the dissipate it back into the line current.

    The energy has to go someplace. UL 1449 ratings for SPDs are based on a series of tests using 20µs pulses at thousands of volts and thousands of amps to determine their effectiveness and longevity. Imagine 6,000 Volts at 3,000 Amps (18 million VA, one of the standard tests) hitting an MOV less than an inch in diameter. If it didn't conduct that energy someplace, it would go supernova. If all the energy were conducted back into the line, it would vaporize the conductors in a fraction of a second. Then what? It finds another path to ground. Give it a short, straight path to ground and it won't destroy your stuff.

    Thanks to resistance, much of the energy of a strike is transformed into heat -- heating the air, then the building structure (especially the wires), heating the SPD itself, and ultimately boiling some of the water trapped in the soil. That's how it splits rocks, creates craters, etc.

    This PDF describes changes made in the 3rd edition of UL 1449, which took effect in 2009.
  • Harvey Ramer
    Harvey Ramer Member Posts: 2,261
    Options
    I'm not going to disagree with you. You obviously know a lot more about it than do I. Just repeating what I was told. Your explanation makes a great deal more sense than the rep's.
    SWEI
  • ChrisJ
    ChrisJ Member Posts: 15,923
    Options
    SWEI said:

    The sq-d Rep told me their whole house surge protectors absorb the surge and the dissipate it back into the line current.

    The energy has to go someplace. UL 1449 ratings for SPDs are based on a series of tests using 20µs pulses at thousands of volts and thousands of amps to determine their effectiveness and longevity. Imagine 6,000 Volts at 3,000 Amps (18 million VA, one of the standard tests) hitting an MOV less than an inch in diameter. If it didn't conduct that energy someplace, it would go supernova. If all the energy were conducted back into the line, it would vaporize the conductors in a fraction of a second. Then what? It finds another path to ground. Give it a short, straight path to ground and it won't destroy your stuff.

    Thanks to resistance, much of the energy of a strike is transformed into heat -- heating the air, then the building structure (especially the wires), heating the SPD itself, and ultimately boiling some of the water trapped in the soil. That's how it splits rocks, creates craters, etc.

    This PDF describes changes made in the 3rd edition of UL 1449, which took effect in 2009.
    If you have a device across the two phases I see no reason the current couldn't be shunted across the two rather into the neutral.

    I thought about this when Harvey said it, seemed plausible to me.

    Also, for now I'm going to have to respectfully disagree regarding lightning being RF.

    Best I can tell, lightning does produce RF, but it itself is not RF. The RF it produces is all over the spectrum.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • SWEI
    SWEI Member Posts: 7,356
    Options
    ChrisJ said:

    Best I can tell, lightning does produce RF, but it itself is not RF. The RF it produces is all over the spectrum.

    Call it a series of pulses if you want. Fourier explained this back in 1807. A square wave can be characterized as a series of harmonically-related sine waves. The sharper the corners on the square, the more (and higher) harmonics are required in the series to create it. NFPA 780, US Army TM 5-690, Motorola R56, and more specify minimum bend radii for lightning conductors precisely because of the spectral content of lightning energy. It can literally jump off sharp corners.