We have a small tracking solar array that runs our meager electric system. We are off grid here in San Felipe Baja. Tried to replace our old water and probably electrically inefficient washing machine with a new one. Both failed to work with the 97 volts coming out of our inverter. Is this something common to all new electronic devices-they won't run without a minimum voltage. Old one ran fine but we tested the amount of water it used (70 gals per load) and that is unacceptable both for water consumption and the load on the old septic system.
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Hedges
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Electronics is getting cheaper. You should be able to get a sine wave inverter for not too much money. Look one with wattage rating (or at least surge rating) 5x greater than nameplate of washer, to start the motor.
"tracking solar array"
These days PV panels are so cheap it make more sense to put in more panels and orient some East, some West.
But maybe the new washer will use fewer watts than the older one.
"new water"
Do you mean water heater? If so, don't run at same time as washer, to reduce load.
"tracking solar array"
These days PV panels are so cheap it make more sense to put in more panels and orient some East, some West.
But maybe the new washer will use fewer watts than the older one.
"new water"
Do you mean water heater? If so, don't run at same time as washer, to reduce load.
Good question, it is an old Freedom 20 inverter paired to 4 Duracell 6 volt batteries (all from previous owner). I pulled up a different site that suggested modern washing machines need pure sine wave inverters and the Freedom series are all modified sine waves. Thanks
chrisski
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When I lived in Japan, it had 100 volts, 50 hz, so perhaps a washer designed for that will work on your system, if your inverter truly is supposed to put out 100 volts.
Most times, any American device you plugged in worked fine, but for American washing machines, you needed a transformer or it would run "noisy."
Most times, any American device you plugged in worked fine, but for American washing machines, you needed a transformer or it would run "noisy."
"Old water" was an awkward attempt to string together the water use inefficiency and the presumed electrical inefficiency. Too clever by half. We will be talking to our solar guy about a pure sine wave inverter tomorrow. Tracking panels are remnant (along with everything else in the system) of previous owner but will leave until it stops working. Thanks
thanks for that. I think I will be upgrading to a pure sine inverter. Our solar guy installed a system next door and they are running a washing machine from the same place we tried to buy one yesterday so presumably we can get and install the same inverter but we are in MX and there are issues with obtaining some components-we can't get batteries right now.
Hedges
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Some old but not dead car batteries should get the system running. So long as things are operated during hours when PV generates enough power for them, batteries just supply motor starting surge for a second.
I like an over-paneled system where PV panels make more power than I need and it is just wasted, rather than large battery bank to store the power. Batteries cost several times as much as PV panels. Set up relays to turn on loads when batteries are full. The batteries just need to accept as much charge current as could be produced. I think car batteries can take a high initial current, but gel-cell is limited.
I like an over-paneled system where PV panels make more power than I need and it is just wasted, rather than large battery bank to store the power. Batteries cost several times as much as PV panels. Set up relays to turn on loads when batteries are full. The batteries just need to accept as much charge current as could be produced. I think car batteries can take a high initial current, but gel-cell is limited.
T
Turns out that the harbor freight multimeter I was using was a non-RMF multimeter and does not give reliable readings off an inverter. I happened to have another multimeter and that one gave a higher reading (105)
Hedges
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I was thinking exactly that, did some Googling but didn't find the correction factor and dropped it.
Is the other meter "true RMS" or not? Sometimes those actually measure the heating of a resistor to determine voltage. (cheaper than a high speed ADC). I'm thinking actual RMS may be closer to 110 or 120V. "Modified sine wave" (Which I call "modified square wave") goes from zero to <a higher voltage> but has some dead time at zero before reversing polarity. (not "120V or whatever the RMS is supposed to be", which is the case for square wave)
Don't know your budget, but we've seen some great deals on products in the US, used and surplus. Some may be a larger scale (more expensive) system than you want.
Is the other meter "true RMS" or not? Sometimes those actually measure the heating of a resistor to determine voltage. (cheaper than a high speed ADC). I'm thinking actual RMS may be closer to 110 or 120V. "Modified sine wave" (Which I call "modified square wave") goes from zero to <a higher voltage> but has some dead time at zero before reversing polarity. (not "120V or whatever the RMS is supposed to be", which is the case for square wave)
Don't know your budget, but we've seen some great deals on products in the US, used and surplus. Some may be a larger scale (more expensive) system than you want.
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Ironic that when I talked to my solar contractor just now he reported that somebody else in the same part of our development (we are all off grid) had exactly the same issue and reported the same result (getting a low reading on a non RMS -I was using RMF off what I heard in the You Tube video). I do not know whether the other multimeter is RMS or not-I bought it here in MX last year so thinking not but having a different reading gives a little credence to the theory that it is the multimeter and not the inverter? We made a deal to install a 24v pure sine wave inverter using the same set up that we were going to use for the 12v system. Should be here about the same time as the new batteries so theoretically things should be good.
chrisski
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I have not heard about the RMF multim
If you’re talking about root mean square, that should be 120 volts x .7= 84 volts or 96 x 1.4 = 134 volts, neither of which adds up.
The .7 and 1.4 is the coefficient for a pure sine wave, so since you’re isn’t a pure sine wave could be different coefficient
Learned about RMS in electronics school, but never in the six years I worked as an electronics technician use it or ever see an RMS multimeter. That was 25 years ago.
Your coefficient is exactly .8 If your volts really are 120 and maybe that’s Because of the modified sine wave gives you a little extra RMS power.
If you’re talking about root mean square, that should be 120 volts x .7= 84 volts or 96 x 1.4 = 134 volts, neither of which adds up.
The .7 and 1.4 is the coefficient for a pure sine wave, so since you’re isn’t a pure sine wave could be different coefficient
Learned about RMS in electronics school, but never in the six years I worked as an electronics technician use it or ever see an RMS multimeter. That was 25 years ago.
Your coefficient is exactly .8 If your volts really are 120 and maybe that’s Because of the modified sine wave gives you a little extra RMS power.
Hedges
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"Modified sine wave" has the same RMS value as true sine wave.
I incorrectly said it's peak was 120V. A square wave of 120V peak would be 120V RMS.
Modified sine wave goes higher, but has 120V RMS so light bulbs and resistive loads run at he correct power. Harmonics are less ugly than square wave, but still an issue for some loads.
The good stuff is available. A picture on the following page shows some waveforms, but not modified sine wave.
www.fluke.com
I incorrectly said it's peak was 120V. A square wave of 120V peak would be 120V RMS.
Modified sine wave goes higher, but has 120V RMS so light bulbs and resistive loads run at he correct power. Harmonics are less ugly than square wave, but still an issue for some loads.
The good stuff is available. A picture on the following page shows some waveforms, but not modified sine wave.
What is true-RMS?
The need for true-RMS meters has grown as the possibility of non-sinusoidal waves in circuits has greatly increased in recent years. Some examples include variable speed motor drives, electronic ballasts, computers, HVAC, and solid-state environments.
www.fluke.com
