Generator testing!

[longview]

What wattage is the generator? Also is it a pure sine wave or modified sine wave? To put it simply most generators labelled pure sine wave are inverter generators, while most non inverter generators are modified sine wave. The sine wave makes a difference on what is used, for example an lcd tv or a desktop computer might work but act unpredictably, while a laptop might run fine on a modified sinewave as the battery and power inverter acts as a filter.

The more delicate the circuitry, the more the wave matters. If you have old incandescent bulbs in a light fixture, try it with a modified sine wave, the bulb flickers like crazy, on some electronics this can cause hell. The good news it however if you have something like computers modern tv sets and other modern gizmos you want to protect and run with a modified sine wave, an uninteruptable power supply or upc convertes the wave for you and they are fairly cheap so you can keep those if you do not have an inverter generator or are unsure. Things like light bulbs, refridgerators, microwaves electric space heaters etc do not care how pure the wave is, they do not need a pure wave.

Depending on the size of the house and how many are using electronics, 5-10k generator will run the entire house minus ac, electric heaters(house heaters not space heaters) dryers and electric stoves. For the rest it depends on how much juice you need to kickstart, and the running wattage. Some houses may run 5-6k watts continuous but need upwards of 20k watts to kick start multiple devices like ac and other not so soft start devices. This also depends on the size of the ac unit, or wattage of heaters and electric stove, as well as the wattage needed to start the fan for said heater/ac.

Many devices have capacitors to handle surge voltage, infact most do, however the capacitors reduce starting voltage requirement, but can not eliminate it short of a monster sized one as startup draws a lot of juice, it also depends on the charge and discharge rate of the capacitor, as a capacitor is basically a quick charge/discharge battery.

I have a 10,000 watt Fermen, and it is a sign wave, simply because the motor spins the generator.
My AC controller seems to be the most sensitive, but came up just fine.
I ended up running on generator for about 12 hours Yesterday, but power down when we went to bed.
I also test ran a small AC for a few hours to dehumidify my bedroom.
Fridge, Freezer, microwave, electric stove top all worked fine. Next time I run it, I will drag out the Oscilloscope and look at the quality of the sign wave.

 

[RAMOSS]

Well my Neighbor has one of the automatic ones, so I think I may hear when his goes off.

My local electric company let's me get text messages when there are power outages and restoration. i bet yours can do the same.

I log on to my electric company account to report it, and then they just text me when they think power is restored.

 

[fortune]

On my path to retirement, I have been doing projects that I would rather do while working.
One of those is a generator feeding the electrical panel of the house.
I had the new panel put in (Manual switch interlock) and rigged the natural gas generator to run inside a storage box,
but had not gotten around to testing the system.
Well about noon my time the power went off, on it's own.
I went out, plugged in the gas line, and the power cord, turned on the gas and fired the generator up.
At the breaker box, I switched off the mail, and the central AC, lifter the interlock, and engaged the generator.
not really surprised, but everything works.
My wife defrosted lunch in the microwave and then cooked with the electric range, everything normal.
I do not think my generator would start my 5 ton AC, so did not even bother, I have portables if the power outage continued for several days.
for now I am wondering how I will know when the power comes back on?

A few years back some dude with a high powered rifle took target practice at a main power transfer station 20 miles out in the boonies. Power was down for 36 hours for the whole town. Just the year before I installed a Genrac that can power my house with AC non stop fueled via propane tank. It checks itself by starting up once a week and "exercising" for 15 mins.

Last week we were 105 degrees F and the power in the town went down again for 90 minutes. No problem. It starts right up when it senses a power outage.

 

[beerftw]

I have a 10,000 watt Fermen, and it is a sign wave, simply because the motor spins the generator.
My AC controller seems to be the most sensitive, but came up just fine.
I ended up running on generator for about 12 hours Yesterday, but power down when we went to bed.
I also test ran a small AC for a few hours to dehumidify my bedroom.
Fridge, Freezer, microwave, electric stove top all worked fine. Next time I run it, I will drag out the Oscilloscope and look at the quality of the sign wave.

10k will run everything in a normal size house just fine, the ac is iffy because it depends on the size and startuo draw, but 10 is a good number to have.

Most electronics work fine with modified sine wave, it is just the sensative ones you need a filter for too easy to use a ups as a filter for the few sensative electronics.

Oh man an oscilloscope, I use those to test computer commands, ignition waveforms, and alternator testing, it is rare to see anyone use them, whether automotive tech or electrician. It is so bad when I started doing automotive sun scopes were the rage, now scopes are needed more than ever but the vast majority of mechanics will not touch them, same with electricians. Electronics have become more complex over the years and it saddens me techs in all fields have avoided using proper test equipment and have cornered themselves into parts cannons.

 

[fortune]

10k will run everything in a normal size house just fine, the ac is iffy because it depends on the size and startuo draw, but 10 is a good number to have.

Most electronics work fine with modified sine wave, it is just the sensative ones you need a filter for too easy to use a ups as a filter for the few sensative electronics.

Oh man an oscilloscope, I use those to test computer commands, ignition waveforms, and alternator testing, it is rare to see anyone use them, whether automotive tech or electrician. It is so bad when I started doing automotive sun scopes were the rage, now scopes are needed more than ever but the vast majority of mechanics will not touch them, same with electricians. Electronics have become more complex over the years and it saddens me techs in all fields have avoided using proper test equipment and have cornered themselves into parts cannons.

BTW how does a "modfied" sine wave work? I mean I know what a sine wave is but I also know you cannot add your power to the sysyem unless it is in synk/

 

[beerftw]

BTW how does a "modfied" sine wave work? I mean I know what a sine wave is but I also know you cannot add your power to the sysyem unless it is in synk/

A sine wave looks like waves of a perfectly sloped nature, a modified sine wave looks like waves with jagged edges in them, On electronics that do not care both will work, on highly sensitive electronics an impure sine wave or modified sine wave will cause hell.

In automotive I deal with something similar, alternators produce ac current but it get's converted to dc current, while power lines deliver ac current and have the appliance convert it to dc.

In a car there is an acceptable amount of ac current allowed past the diodes and rectifier bridge, in older cars too much would cause lights to flicker, in modern cars computers go haywire.

To put it simply you can google modified sine wave, but a modified sine wave is a dirty signal while a pure one is a clean signal, both power things up but it depends on how sensative they are, for example using a modified sine wave generator a fridge will run fine, but lights might flicker a little, but running a digital tv it might cause serious issues due to the emi from the power source.

 

[Court Jester]

On my path to retirement, I have been doing projects that I would rather do while working.
One of those is a generator feeding the electrical panel of the house.
I had the new panel put in (Manual switch interlock) and rigged the natural gas generator to run inside a storage box,
but had not gotten around to testing the system.
Well about noon my time the power went off, on it's own.
I went out, plugged in the gas line, and the power cord, turned on the gas and fired the generator up.
At the breaker box, I switched off the mail, and the central AC, lifter the interlock, and engaged the generator.
not really surprised, but everything works.
My wife defrosted lunch in the microwave and then cooked with the electric range, everything normal.
I do not think my generator would start my 5 ton AC, so did not even bother, I have portables if the power outage continued for several days.
for now I am wondering how I will know when the power comes back on?

Does your neighborhood have streetlights? That is how I tell at night. That or just observe other houses in the neighborhood and when their lights come on.

They sell I believe a device that alerts you when power comes back to your line which you hook up to your panel.

 

[Court Jester]

A typical (4 to 5 ton) central A/C system has a 40 amp breaker - our small house (2.5 ton) central A/C unit only needs a 25 amp breaker. The problem is that when you subtract that 40 amps from your 50 amp total you are left with (essentially) nothing but enough to run a few light bulbs. Best to resign yourself to doing without the A/C during power outages or frequently fiddling with the breaker panel settings.

I agree. I have one 2000w portable propane powered INVERTER in case I need to quickly get a few lights, some fans, and the internet. But it is not enough to start up a refrigerator compressor, and I have two fridges. Then after that I have a 4500w inverter in case power will be out for more than a couple hours, or even a few days that I can roll out. This like an RV type, so it is pretty quiet, and as noted you really need inverters not just cheapo Home Depot open frame power generators that could damage electronics. The 4500w I have is just so not to lose all the food in the fridge, which is just a hassle. Otherwise I am fine with going without AC.


I also have the ability to parallel run the 2000w and the 4500w if needed, if the outage goes for days. Thus increasing start up wattage more efficiently with the appliances.

Automatic transfer set ups are great; I just didn't want to spend the money, and once you start fiddling with an electrical panel that at least 20 years old, you run into issues possibly and then need to replace that too.

 

[longview]

Does your neighborhood have streetlights? That is how I tell at night. That or just observe other houses in the neighborhood and when their lights come on.

They sell I believe a device that alerts you when power comes back to your line which you hook up to your panel.

I figured it out, when the power comes back on, the digital meter powers up, (It is right next to the generator.)