Having a generator inquiry

[chessimprov]

I know nothing about having an electric generator.

I live in a community association that does not allow for a permanent generator (unless doctor's orders and that a portable generator would not suffice.)

How would I go about buying a portable generator? What do I have to be aware of for usage, cost, maintenance, accessibility to call for repairs without it interfering with my job if at all possible?

Thank you.

 

[Stuff]

First is to determine why you want one and what it would be used for. Permanent unit with automatic transfer panel is great for healthcare needs. Just worrying about your refrigerator means running an extension cord to a properly sized unit.

 

[Sponsor]

 

[LLigetfa]

You could always go with batteries and an inverter. Are you on time of use billing where you pay more for power on-peak? Maybe a Tesla Powerwall that charges during off-peak and supplements on-peak could pay for itself over time.
http://large.stanford.edu/courses/2016/ph240/furrer1/

 

[chessimprov]

I don't think I'm on an on-peak cycle currently.
A generator would be helpful for my usage of a cpap machine mainly, but could be useful for the refrigerator, cell phone, and less importantly, using the TV or computer.

I've heard from a friend that the generator she has produces carbon monoxide. But, that is a permanent one and it is outdoors.
I'm guessing this battery powered one and an inverter would not produce something like that?

 

[FullySprinklered]

I just set up a portable unit at my place. It would be for ice storms and tornados taking out the electric. Scroll down to "Generator Grounding Question". It should run the fridge, a small heater, some lamps, microwave, and electronics. I skipped the extension cord option and hard wired a small panel in the unfinished basement and branched out from there. The unit has an RV plug, a 30a twist-lock receptacle, and a regular duplex receptacle. Runs on propane and/or gasoline. It needs to stay outdoors unless you want the heaven option.

 

[Stuff]

For CPAP the best would be a point of use UPS as you want it to kick in when the power goes when you are asleep. Get a UPS that you can turn the audible alarm off. This will get you through power outages up to several hours.

Almost all portable generators run on gasoline so you can't run them in the garage. So when you have an outage you have to drag it outdoors and run a cable. A electrical panel transfer switch can then connect to your whole house. Problem is you need to turn everything off or you will trip the breaker on the generator.

 

[FullySprinklered]

My little subpanel is generator-only, no transfer switch necessary. Nothing automatically comes on, it's all by hand when the outage occurs. My generator is outside on the deck covered with a fitted waterproof cover. The 20# propane tank has it's own cover.

 

[FullySprinklered]

I may get a solar unit for a back-up if the fossils run out.

 

[Jadnashua]

How much power does the cpap machine use? I looked at one, and it only used 18W. Most probably do not use all that much. IF so, the suggestion of running it off of a UPS is probably your cheapest and easiest way forward. YOu can buy UPS devices in all sorts of sizes and you'd need to decide how long you want the things plugged into it must run. I wouldn't try to run a refrigerator off of one, but the cpap and maybe charge your cellphone, should be doable. With such a small load, you could easily run a cpap machine for several nights off of one. Eventually, it would discharge its batteries if you can't get power back, though.

Any engine driven generator will produce some CO, so needs to be outside. Many of the small ones don't have that big of a gas tank, and depending on the load, may only run a few hours before you have to refuel it. They don't automatically start, and if you needed to run outside to refill it a few times a night, wouldn't be all that useful if you're trying to sleep through the night.

An automatically starting/switching generator will cost you thousands. You can buy them that run off of natural gas, so you don't have to worry about gasoline, propane, or diesel. Those can be sized to power your whole house, or only switch certain critical loads (say the furnace, refrigerator/freezer, and some lights).

 

[FullySprinklered]

Natural gas is absolutely the best option. Don't have it here, unfortunately. You get nine hours from a 20# propane tank, and a little more from the 3.5 gallon gasoline tank. You can switch between the two, but a constant flow from a natural gas connection is as good as it gets.

 

[Cacher_Chick]

How do you isolate the generator-powered circuits from the main panel if you don't have a transfer switch? What protects the utility worker from getting shocked by your generator when they have disconnected their feed while they are doing maintenance or repairs?

 

[FullySprinklered]

How do you isolate the generator-powered circuits from the main panel if you don't have a transfer switch? What protects the utility worker from getting shocked by your generator when they have disconnected their feed while they are doing maintenance or repairs?

They don't connect at all. I have an unfinished basement with access to every room in the main floor from below. I ran my circuits (actually all dedicated circuits) from the little panel straight to new outlets where needed. The ground lug on the generator is connected to a bare copper wire outside for lightning protection, but the power and neutral are totally separate from the service. What happens in generator, stays in generator. Puzzled me for a while, also.

All this is really easy, especially if you're just using extension cords. Hook it up like a gas grill, put it on choke, push the button and it fires right up. Turn the choke off and plug stuff in.

 

[Cacher_Chick]

They don't connect at all. I have an unfinished basement with access to every room in the main floor from below. I ran my circuits (actually all dedicated circuits) from the little panel straight to new outlets where needed. The ground lug on the generator is connected to a bare copper wire outside for lightning protection, but the power and neutral are totally separate from the service. What happens in generator, stays in generator. Puzzled me for a while, also.

All this is really easy, especially if you're just using extension cords. Hook it up like a gas grill, put it on choke, push the button and it fires right up. Turn the choke off and plug stuff in.

That is the way to do it. I have heard of many people plugging the generator into the existing service with no regard to the neutral, which does not have a disconnect except in a proper transfer switch, or by pulling the meter. Lineman have died because of this practice.

 

[Jadnashua]

First thing you need to decide is what item(s) are critical to you to have operating if the power goes off. Then, you must determine if it is critical for them to operate with either no or a short delay, or if a manual connection made after you notice the power outage is acceptable.

An automatic, whole house generator backup is certainly the most convenient, but also the most expensive.

If you only want to power a single, critical item like your CPAP machine, put it on a UPS. If you can wait, unplug then run extension cords to a few things, a small generator will work. Anything larger, you'd probably want to put in a transfer switch (either manual or automatic) to enable those selected circuits to operate off of the generator. Some generators have 'dirty' power - the frequency and voltage level may not be well controlled. Some things won't like it, and may not run properly. Some won't care.

Until you decide what's important to you, and how much you're willing to pay, the number of options is just too high to really narrow things down.

 

[WorthFlorida]

I know nothing about having an electric generator............How would I go about buying a portable generator? What do I have to be aware of for usage, cost, maintenance, accessibility to call for repairs without it interfering with my job if at all possible?Thank you.

Portable generators are not as easy as most might think and all fuel power generators do produce carbon monoxide. Anytime you run it it must be well away from any windows and not in or near the garage. A light breeze can pull CO into the home.

I have two of them I bought over the years, mainly for power outages after hurricanes. Depending on size they do get quite heavy. A typical 5KW gas unit will weight over 150lbs. Sure they have wheels but most are pneumatic and they always lose air after few months of storage. Try to pull one out with no air is quite a chore. After use you do not want store it with gasoline in the tank. You can use Fuel Saver but that is only good for about six months since gas can go bad. 5KW units will have 3.5 to 5 gallon tanks so depending what left in the tank, draining it can be challenging. If you want to run it until it runs out of gas, with no load it can take eight hours.

The next challenge is gasoline. I have five 5 gallons cans. If I a hurricane is a possibility, I'll fill all of them up and add a fuel saver additive. At the end of the hurricane season I put this gas in my truck but during storage you do not want to store this amount of gas inside a garage. Why so much? When power is out there is no gas anywhere. Most stations do not have power so no one is pumping gas. Those that do have AUX power (Florida requirement for new gas stations) there be 100 cars in line for gas. You're in Philly area and a ice storm unexpectedly hits more severe than forecasted, power is out, streets or slick, now you need gas, but how much and where do you get some?

With a portable you need a good supply of extension cords and you need to run then throught a window or door. Maintenance wise there is little to do with them. Once a year you pull it out and pull in a little gas, maybe a quart, and run the machine. Oil and air filter changes, if rarely used, will not be needed. Usually the every fifty hours of use.

Since you asked many questions about generators the small portable units may be your best choice. Honda has a 1800 watt unit for about $1100 and weights 50 lbs. This will easily handle your electronic needs, some lights and the CPAC machine but probably the refrigerator. They do not use much gas, easy to handle and fairly quiet compared to much larger units. Just remember that you use your CPAC at night, a generator running all night your neighbors may not like to hear the roar of it, unless to hand them an extension cord connected to the generator.

 

[FullySprinklered]

One question I have concerns electronics. Is it safe to run/charge my laptop and phones from the generator?

 

[WorthFlorida]

One question I have concerns electronics. Is it safe to run/charge my laptop and phones from the generator?

Just about everything electronic that plugs in has a power supply input from 120v-240v 50-60hz. The manfactures only have to package the correct power cord for the country the product is being shipped to. Unless your running heavy power tools like hammer drills that can cause good spikes and noise on the line you’d be ok. During one hurricane I ran two refrigerators, a fan and a flat screen TV and had no problems. Just had to use an indoor antenna since cable tv was knocked out. It was on a 2500 watt Craftsmen generator.

Those nice little Honda units that state “inverter” are DC generators with an inverter for AC output. They claim very clean output for sensitive electronics.

 

[Reach4]

I agree. These wide input voltage chargers are going to be tolerant of a generator. I would add that I like to keep a spare charger for each. They can be cheap when ordered in advance. A charger can fail due to a flexed wire, or you can leave it somewhere. If you have a spare, a broken or left-behind charger is not a big deal.

 

[LLigetfa]

Often it is the HZ more so than the volts that can cause problems with some power supplies. With inverters, it is often the waveform that some power supplies don't like. Standby UPS systems just feed through the AC until there is a power failure and then turn on their inverters and switch over to them. Many of them have a really bad waveform that might not work on all loads.

I have setup power systems for datacentres that included UPS systems and automatic backup generators that ran on natural gas. I used online UPS systems that ran the inverters all the time (AC-to-DC-to-AC).

 

[Jadnashua]

Some power supplies will have problems with a non-true sinewave acv signal. Many pseudo sinewave outputs are raggedly stepped square waves. FWIW, a square wave has HORRIBLE noise characteristics...a true sinewave has no harmonics - it is a single tone. As was mentioned, some things really are also fussy about the frequency of that input wave. There are some things that don't care at all (an incandescent light bulb doesn't care if it's a sinewave or continuous DCV, as long as the level is okay).

Some circuits will pass an ac voltage, but will block a DC one. When a pseudo sinewave is stepping, it goes from conducting to blocking to conducting as the cycle steps up then holds a bit then steps again.