spike protection

I have a power inverter in my house that I use to run a water pump and couple of lights, outside of the house, but the inverter output is too hight. Output is

127 ac volt and I'm having some problems with lights burning out fricuenlly. What can I used to protect my pump and lights from this high spike voltage?
Reply to
junior1308
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"junior1308" wrote in message news:36e1b$55e3a1ae$43de0cc0$ snipped-for-privacy@news.flashnewsgroups.com...

Try something other than filament lamps, such as LED lamps.

Reply to
John Smith

Fix your unspecified model inverter to reduce the output voltage to

115 Vrms. Some inverters have programmable, adjustable, or jumperable output voltage settings. You can add a step down transformer to lower the voltage, but I think the heavily load of the pump will cause problems.

Also, check how your unspecified model inverter responds to drastic changes in load, such as when the pump starts and stops. If it's a cheap Chinese inverter, it's likely that it will respond quickly, but produce a dramatic overshoot in voltage when the load is removed (i.e. the pump motor stops). My guess(tm) is that it's this overshoot that's killing your lights, not the 127V (about 10% over nominal voltage).

Also, if you're on 2 phase power (most houses are), measure the voltage on both phases. If they're radically different, such as 127v on one phase and 105v on the other (i.e. +10% and -10%), you have a problem with the neutral wire. If you see this, put a clamp on ammeter around the neutral and see if there's any current flowing through the neutral. If so, you may need to move some breakers from one phase to the other to balance the two phases. It's also a possible indication of too much resistance in the house wiring (i.e. aluminum wiring), which might need to be addressed. If you get to this part, I suggest calling an electrician instead of trying to fix it yourself.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
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Reply to
Jeff Liebermann

127v ac doesn't sound like anything to do with spikes, just too high a voltage. Either get an invertor that works properly, or add a transformer on the output to reduce the voltage a bit.

I'm wondering why the invertor, presumably the house is off grid.

NT

Reply to
tabbypurr

There are other possibilities. He could have a broken volts guesser. The output waveform of the inverter might be full of harmonics, such as a "modified square wave" waveform. Perhaps some kind of bizarre wiring error where the meter is measuring a combination of grid voltage and inverter voltage. If grid tied, the inverter output voltage usually tracks the grid at slightly below the grid voltage, so that most of the load is being fed by the grid. If the grid voltage is too high, so will the inverter output voltage.

Perhaps it would be helpful if the OP supplied more clues as to what he's working with?

Rural wells are usually located away from the house to prevent contamination by the septic tank. Also, wells are drilled where there is water, not for the convenience of the owner. Therefore, the well house tends to be far away from the house, especially if the water is used for irrigation. Running power wires to the well house is often problematic. Therefore, the well house is often powered by a solar array charging local batteries. Lights are nice when the system craps out in the middle of the night. I included mention of house wiring and grid tied issues just in case my guesswork is off the mark.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
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Reply to
Jeff Liebermann

** Standard (non rms) multimeters tend to under read "modified square" waveforms which makes that 127V reading even more suspect.

Modified square wave inverters need to match both the peak and rms values of a 120V sine wave to work well with various loads, including incandescent lamps. This is achieved by making the duty cycle variable with no output for part of each half cycle.

The ideal situation is when the peak value is 170V with a duty cycle 0.5, then the rms value is exactly 120V and the peak value the same as sine wave. In this case, a non rms AC meter reads 94V.

If the battery sags and the peak voltage falls to say 150V, the duty cycle should increase to 0.64 to keep the rms voltage steady. In this case a non rms AC meter reads 107V.

.... Phil

Reply to
Phil Allison

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