Hello to All. This is my first post.

In rural areas there are more likely significant voltage fluctuations with power from the grid, and more than average power outages, some of them quite long.

I'm trying to find the best approach to running computer equipment off a generator (non inverter type). As you all know, this type of energy is quite dirty and nowhere near a pure sine wave.

a) Can computers run safely off of dirty electricity from a generator if you have a Line-Interactive UPS system that has an AVR that will adjust for small line fluctuations and surge protection? I understand the current will not be a pure sine wave,
b) If not, is the only course of action to buy an OnLine UPS Double-Conversion type, much more expensive unfortunately,
c) Are there any other options, e.g. an inverter along with surge protection.

Thanks

BillXHere's a quick response.
Most modern gasoline powered generators have very clean outputs and you have little to worry about. But if you are in doubt, have a technician check it out with an oscilloscope and a dummy load to see what it looks like. I'm sure it'll be very close to 99% pure sine wave.

Now if you are talking about analog audio equipment, that is something else.
Some posts found elsewhere seem to be concerned about line noise, which is a big thing for analog audio recording work..

Now as to modern computers. Unlike some older analog electronic devices, modern computers and wide tolerance for power-line noise and trash. In fact, the computer itself uses a switching power supply which has the capability to produce more noise than you can imagine. Nevertheless, the DC output of the switching power supplies is very clean and state-of-the-art.
Some commercial operators prefer to have a UPS unit to ensure that the power is always extremely clean. However, in some cases the UPS is not as reliable as anything else. The UPS is more of a backup system and not really a guarantee that the power supply to your equipment will always be pure and STEADY.
If the generators well-maintained and used properly, it should provide steady clean power. One of the concerns is that the gas must be clean. And also the air intake manifold has to be checked regularly and you have to make sure no dust hits and. And of course, the gasoline generator must be well ventilated.
As I said, this is a quick answer based on my personal knowledge and experience.
Hope this is of some help.Gonna have to disagree on this one with Geek...1 of the best features of a UPS is clean steady power...it's the 2nd most important thing they do...after supplying backup power...Thanks for replying, Geek and patio.

@Geek:

The clean generators you are referring to must be the inverter type, which are costing less nowadays, but I don't have one of those. An oscilloscope would be ideal if nothing else but curiosity. My signal might be better than I think, but most refer to non-inverter types as dirty power.

When you are saying UPS, are you referring to StandBy or Line InterActive. I understand that the standby units don't have a AVR and are pretty much surge protection with battery back-up, which might be enough in normal situations (non generator use). Line InterActive ones seem a good idea controlling even slight fluctuations, and with an inverter generator would have to be enough for sure, making an OnLine UPS overkill.

@patio

The promos refer to the pure sine wave output of StandBy, Line-InterActive and OnLine UPS's as very clean. But the first 2 will have no say in sine wave pattern coming from the grid or a generator. I thought that what comes from a generator is what you get re sine pattern, unless an OnLine is used.

Much appreciated to you both. More to consider here.

I will stick to my statement until proven otherwise.
The people who make UPS devices say they are good. But my own experiences is the are more often the cause of trouble.
Unless you have real measurements, it is guess work.
Here is a quote:
Quote

This nagging "power quality problem" had nothing to do with power quality. Why? With the information provided by a power disturbance ANALYZER, the engineers determined the following vital information:

a) Can computers run safely off of dirty electricity from a generator if you have a Line-Interactive UPS system that has an AVR that will adjust for small line fluctuations and surge protection? I understand the current will not be a pure sine wave,
b) If not, is the only course of action to buy an OnLine UPS Double-Conversion type, much more expensive unfortunately,
c) Are there any other options, e.g. an inverter along with surge protection.

Biggest thing with a generator for your home is to make sure you have the proper switchgear to isolate your generator from the utility pole. I have to be really careful here about what i say because I dont want to list any methods people have used to power their home (backfeeding) their breaker box which can at all be suggestive.

Do you have a professionally installed generator? or just one of those portable gasoline ones like I have.

I live in an area of New England that loses power frequently. I have a Champion 6500 watt portable 120/240VAV with 7.7 gallon gas tank with a run time of about 11 hours on a full tank of gas.

I have learned with my generator that the standard off the shelf battery backups DO NOT LIKE being powered off of a generator. I even borrowed my brothers generator in which he has a better Honda brand generator and the battery backups in my home acted the same. They click about once click every second as it switches back and forth between passive mode sending the power to devices powered through it and then correcting for dirty sine wave in which it uses the battery. The last time we lost power for 7 hours and I had the generator going, the battery backup kept clicking as it was switching back and forth from passive to active power to the devices plugged into it. After about 4 hours the lead acid battery went dead in the 750VA battery backup as for all that compensating drained the sealed lead acid battery. The same battery backup without generator would keep all the same stuff going for about 20 minutes just off the battery only. So the problem with standard battery backups are that the use of the battery to compensate uses more power than is able to be stored back to the battery during the charge cycle when it switches back to passive.

You really should have a OnLine UPS Double-Conversion type as the solution.

Bare minimum protection from a generator is to have a surge protected power strip to protect from any spikes. Laptops are safer with generator power as for the power supply that charges the laptop battery has pretty good filtration as well as any dips the laptop battery if a healthy battery will keep the computer going without any problems. Desktop computers however really should be powered through the more expensive OnLine UPS Double-Conversion type.

I also have 12V Lead Acid Car Batteries and a 1000 watt inverter. I have been able to use a desktop computer drawing 165 watts for 2 hours on a 750 CCA battery that was recently charged. However during an outage its best to just use one of my laptops. The other benefit of laptop is that when the car battery dies I can swap out the car batteries to the next freshly charged battery and just keep going without having to shutdown the computer, while a desktop computer needs to be shutdown between each battery swap. I like using the car batteries if I need electric and need to be quiet. I have 2 truck batteries and a smaller battery from a Honda Civic that I use for silent power with my 1000 watt inverter.