Generators..........

[D45]

Ok, need some info on generators..........

Gasoline?
Natural Gas?
Propane?

Portable is nice and affordable, and a whole house is a safe best........but expensive

I am looking in the used generator market......and propane and natural gas is really catching my eye.

How long would these run on a #20 tank?

Seems like most will run 8-12 hours on a full tank of gasoline

Seems like less to gum up/stick with NG or propane.......plug it in and go

Also, what is a minimum wattage I should be looking for? Obviously looking to use in an emergency situation, like a power outage

Main kitchen fridge is a concern, upright freezer in the basement, fridge in basement......and obvisously furnace for warmth (if need be). I have a NG fireplace also to help with heat

 

[kd3pc]

Ideally you would identify the actual appliances and calculate the needed run time and current draw (wattage) and so on...Given the information provided, not enough details to do that.

Most consider a 10K watt - "whole house"...but that may not be enough for larger HVAC/R needs. Especially start up and surge loads.

You need a large source of "gas" to run for hours on end...20 pound may only last a day or so at full load on a 10K unit.

Gasoline still provides the best compromise of fuel, run time, current, voltage, portability, etc, etc,

Buying used is a shot in the dark, unless you have run time and full maintenance records and so on...most are not consider continuous duty or for heavy loads over time.

bests on what you decide.

 

[TractorJeff]

Most on here state not long on a 20lb'er.
Freezers and Fridges don't draw as much as they use too.
Furnaces either for that matter.
5000 watt?
Its the well pump that is the after thought when she flushes and the toilet no longer fill that you wish for 7500 watts and 240 volt

 

[polizei1]

I really wouldn't consider one unless it's going to be a permanent mount with automatic switch over, and NG. I would be looking at 10-20kw depending on what you want to run off it and your budget. Pretty sure I'm going to go with a 16kw Generac.

 

[Kaizen]

If you have natural gas i'd go that route and go big as you can so its piped and solid. Propane in a post disaster area won't last long and even a big tank will run out. I wouldn't depend on a propane delivery.
I have a gas one and it *****. Never even use it and have to redo the carb again this year. However with 4 cars in the driveway and filled tanks I have about ten days of run time.

 

[mike93lx]

propane is 4.2#/gallon, so a 20 lb tank will have less than 5 gallons in it. propane contains less energy per gallon than gasoline, so gallon for gallon, it won't run as long on propane. on top of that, the tank will likely freeze up as it is drawn down, lowering the pressure and with it, the usable amount of propane.

20 lb tanks are ok for very small inverter generators, short term use, or for emergencies. If you want to run for several hrs straight or at all in the winter, step up to at least 40lb tanks.

I have an 8kw Ridgid/Honda that I added a propane kit to. Even with a 40lb tank, it was freezing up after about 8 hrs straight at ~25 degrees.

an automatic one hooked up to nat gas is very nice, but multiples more expensive than a portable unit. Sure, my generator is loud and requires effort to use, but i have needed it exactly zero times for backup power in the last 7 years that I have owned it. the only thing an automatic one would get me is a higher natural gas bill.

 

[Tim Kennedy]

D45: Check out --- www.hardydiesel.com --- good sight & info

 

[D45]

Most on here state not long on a 20lb'er.
Freezers and Fridges don't draw as much as they use too.
Furnaces either for that matter.
5000 watt?
Its the well pump that is the after thought when she flushes and the toilet no longer fill that you wish for 7500 watts and 240 volt

I have county supplied sewer, no well pump either.........well water, but its on a community subdivision well with backup power

 

[D45]

http://www.propane-generators.com/propane_usage.php

How long would a 5000 Watt Generator with a 10 HP engine at 50% load run on a 20# propane cylinder?

10hp at 50% load would be using 5 horse power to generate 2500 watts of energy.

5hp x 10,000 btu would consume 50,000 btu per hour.

Using a 20# cylinder that produces 441,600 total btu, the engine consuming 50,000 btu per hour would run for about 8.8 hours.

 

[D45]

I have a NG line buried and running into the enclosed patio, for my grill

There is a quick disconnect fitting on the stub, that can be quickly removed from the grill

I was thinking NG would be a good source also, that could easily be hooked up into a line for the generator

 

[theoldwizard1]

I have county supplied sewer, no well pump either...

Sump pump ?

A couple of refrigerators, freezer, furnace a few lights and a TV your could squeak by with a 3500 watt unit (I did it). 5000 watt and you would be comfortable. With 5000 watts, you could run a coffee make or a microwave if you turn off one of the refrigerators for a short period.

Portable units, in that size range, are LOUD and can use a lot of fuel. Even if you find a good used gasoline model it can be converted to natural gas or propane. Natural gas is probably the easiest. You can have a quick connected mounted outside your house and then a hose run the the generator. You don't want the generator parked too close your house because of carbon monoxide and the noise.

You don't want to use gasoline, diesel or 20# BBQ tanks of propane. Storing enough to get you through a 24-48 hour blackout is a pain.

The quickest and, IMHO, the easiest way to wire a portable generator into an existing breaker panel is a generator interlock kit and an external male plug. With this setup, you can have the power back on in your house in about 10 minutes.

 

[thool]

Take a look at gasoline powered units that you can hook into your house using a 30A pigtail and transfer box. I feed 6 15A circuits with mine (8k watts) and it doesn't bat an eye, so I could have gotten away with a smaller unit.

I feed: sump pump, gas furnace, power vent water heater, 2 fridges, basement lighting, some exterior and interior lighting. The gas stove lights with a match, and I have to run a cord to it to make the hot surface igniter work for the oven.

Maintenance is important no matter what generator you get. Every year, I run mine with a heavy load for about 10 minutes. Then drain the gas, run it dry, and fog it. After running it following a recent outage, the oil got changed.

 

[matt_i]

If you get an older stationary one, check out the natural gas pressure it requires. I almost bought one from my neighbor when he upgraded, but he had to have a different (2nd) meter installed which had regulation to a higher pressure to supply the proper flow of fuel to achieve full HP. After I asked some more questions he paid a $25 monthly meter fee for the 2nd meter. He eventually sold it to a coworker which turned out better in the long run I think. I've only had 2 significant power outages in ~7 years so I've given up on my generator ambitions.

The gaseous fuel (NG, LPG) solves all of your "gumming" issues with gasoline. Also fueling with 89 or 91 octane has less ethanol in it which from my reading is the biggest contributor to "gum". Potentially one could run an "E zero" marine fuel of 87 octane but its tough to find inland and always costs like mad at a marina.

 

[mike93lx]

http://www.propane-generators.com/propane_usage.php

How long would a 5000 Watt Generator with a 10 HP engine at 50% load run on a 20# propane cylinder?

10hp at 50% load would be using 5 horse power to generate 2500 watts of energy.

5hp x 10,000 btu would consume 50,000 btu per hour.

Using a 20# cylinder that produces 441,600 total btu, the engine consuming 50,000 btu per hour would run for about 8.8 hours.

In a perfect world, sure. Realistically, you won't have it balanced ideally and you won't empty the tank due to freezing/pressure drop. Continuous running really needs bigger tanks

 

[Firebrand]

Just another side of the equation is diesel.

I run a military surplus unit, MEP-803A, which can handle my house easily. Look them up as they easily located around the USA at several auction sites.

Dependable, quiet, EMP proof, safe, and did I mention quiet and long lasting?

Yes, they are affordable and portable. Small and lightweight, not exactly.

Just another viewpoint and opinion.

 

[theoldwizard1]

Just another side of the equation is diesel.

I run a military surplus unit, MEP-803A, which can handle my house easily.

How many gallons of diesel fuel do you estimate to run your whole household for 24 hrs ?

 

[Leaflessshadetree]

The smallest stationary units I looked at required more propane than a 20lb cylinder could supply. I believe a 250gal was the minimum recommended tank.
A coworker had to increase the size of his natural gas line when he had a generator installed. Then had to upsize again when he wanted a loarger generator.

 

[D45]

Sump pump ?

A couple of refrigerators, freezer, furnace a few lights and a TV your could squeak by with a 3500 watt unit (I did it). 5000 watt and you would be comfortable. With 5000 watts, you could run a coffee make or a microwave if you turn off one of the refrigerators for a short period.

Portable units, in that size range, are LOUD and can use a lot of fuel.

Good call, yes I forgot about basement sump pump

Knock on wood, we have never lost power for more than a few hours......but I would also like to be prepared

The noise won't be an issue, not a concern for me

There are a ton of used generators all over Craigslist in my area, as well as pawn shops

 

[CJ7VFR]

There are also portable generators that can run on all three types of fuel, called tri-fuel generators. Basically the carbs on them are set up to run on all three types of fuel. You can look into that if you want to be able to use any fuel you want.

For reference, I have a portable 5500/8250 watt, 120/240 volt, 30A generator that runs on just regular gasoline. It has a 7.5 gallon gas tank. When the power goes out, I hook the generator up to a power inlet box on the back of the house that feeds a 10 circuit manual transfer switch inside.

I have it hooked up to run my well pump (240V), septic pump, oil furnace, sump pump, two refrigerators, the circuit that powers my downstairs bathroom light and exhaust fan, one kitchen receptacle to run a coffee maker and a toaster oven (one at a time), the Fios box so I have phone/internet/tv, and the circuit for our living room tv and the my computer.

During hurricane Sandy, the power was out for 11 days! We ran the generator 16 hours a day, and let it rest 8 hours when we were at work and were not home. Doing this kept the refrigerators cold, the heat on when we were home, we could take hot showers, flush the toilets, and make simple, basic food to eat, and drink hot coffee!!

The generator used about 4 gallons of gasoline a day doing this, as it never really ran at 100 percent capacity. If I had to do it over again, I would have looked into the tri-fuel models of portable generators. As it is, I think there is a kit that you can install on a gasoline generator to make it tri-fuel. I am going to look into it more and see if there is a unit for my generator.

Good luck in whichever way you go. Having a generator, even a portable one, to be able to help keep you and your family in your home during a power outage, is a HUGE plus!!! In my case, if we had to go to a hotel for 11 days during hurricane Sandy, it would have cost way more than the $220 worth of gasoline we used over the course of those 11 days, not to mention all the food in the two refrigerators that would have been spoiled. And we were able to stay in our own home.

Jim

 

[D45]

Good information, thanks.........

Looks like a power inlet box on the back of the house with a manual transfer switch might be a good idea to also consider. I would most likely need to hire someone to do this......how much could I expect this to cost?

A portable is still so much cheaper that a permanent "whole house" style........the permanent whole house styles are great, but are $5000 installed

Again, there are so many used generators on Craigslist and pawn shops in my area, that really are more than 50% off new

Gasoline is nice, because it runs for along time......but it runs out. I am still leaning towards a NG setup, because it would be very easy for me with the additional line going into my enclosed patio......and it would never run out

 

[mike93lx]

Easiest and cheapest is to use an interlock on your existing panel. It allows you to power up all circuits and eliminates the need for a separate transfer switch. Add a reliance controls inlet box, a L15-30 cord, and some 10/3 romex and you can be up and running for $250 plus the generator

 

[Falcon67]

http://www.propane-generators.com/propane_usage.php

How long would a 5000 Watt Generator with a 10 HP engine at 50% load run on a 20# propane cylinder?

10hp at 50% load would be using 5 horse power to generate 2500 watts of energy.

5hp x 10,000 btu would consume 50,000 btu per hour.

Using a 20# cylinder that produces 441,600 total btu, the engine consuming 50,000 btu per hour would run for about 8.8 hours.

Our 6500 at 1/2 load uses 5 gallons of gasoline over 7 hours. Propane will do about 1/2 the run time per gallon which is why I went with gas. Hard enough to take enough 91 to run over a 3 day race weekend, ain't hauling around a massive propane tank. And gas is cheaper too.

As for "gum up" - YMMV sure, but our old Champion 3500 sat in the shop for 8 months with some pump gas in it. I used it to test some things in the new trailer, started on the 3rd pull and ran fine. Everything here is 10% ethanol and I never put stabilizer in anything.

 

[D45]

Easiest and cheapest is to use an interlock on your existing panel. It allows you to power up all circuits and eliminates the need for a separate transfer switch. Add a reliance controls inlet box, a L15-30 cord, and some 10/3 romex and you can be up and running for $250 plus the generator

So basically I would buy the interlock for $150 and then add a 30amp circuit breaker ($20) to my current 200amp panel, run some 10/3 to the back of the house for the reliance controls inlet box ($50-$75)??????

Seems very simple

 

[mike93lx]

So basically I would buy the interlock for $150 and then add a 30amp circuit breaker ($20) to my current 200amp panel, run some 10/3 to the back of the house for the reliance controls inlet box ($50-$75)??????

Seems very simple

Yup that's it.

 

[slimcake]

Good information, thanks.........


Gasoline is nice, because it runs for along time......but it runs out. I am still leaning towards a NG setup, because it would be very easy for me with the additional line going into my enclosed patio......and it would never run out

There is no way the gas line that runs your grill is going to run a generator! Just built a house and explored these options. Even for a 7500 watt generator required a direct hookup to the high pressure line before the meter. Then bring on the monthly meter charge..... I put the plug on the back of the house. Then had my electrician wire up one of these awesome transfer switch deals. It can power the whole panel and then I can decide what to turn on or off. Up and running in seconds!! Just shut the main off, slide the plate up and flip the breaker on and it back feeds the panel. Inspection passed just fine. Really no way to screw it up with that sliding plate.

 

[mike93lx]

There is no way the gas line that runs your grill is going to run a generator! Just built a house and explored these options. Even for a 7500 watt generator required a direct hookup to the high pressure line before the meter. Then bring on the monthly meter charge..... I put the plug on the back of the house. Then had my electrician wire up one of these awesome transfer switch deals. It can power the whole panel and then I can decide what to turn on or off. Up and running in seconds!! Just shut the main off, slide the plate up and flip the breaker on and it back feeds the panel. Inspection passed just fine. Really no way to screw it up with that sliding plate.

Fyi, that is an interlock, not a transfer switch

 

[D45]

There is no way the gas line that runs your grill is going to run a generator.

A 3/4" yellow poly NG line wont supply the need flow?

The grill uses a flexible rubber line, with a quick disconnect line, which I would remove when/if the power is lost

I would like have a generator specific line to hook up to the 3/4" yellow poly line........

 

[Firebrick43]

Support your local Indiana economy and get one of these

 

[mike93lx]

A 3/4" yellow poly NG line wont supply the need flow?

The grill uses a flexible rubber line, with a quick disconnect line, which I would remove when/if the power is lost

I would like have a generator specific line to hook up to the 3/4" yellow poly line........

Your grill is probably 40-50k btu. A small engine is about 10k btu per hp. My 8kw generator has a 13hp motor, so you'd be talking 2-3x the consumption of a grill.

 

[mike93lx]

Support your local Indiana economy and get one of these

There's the Garage Journal overkill

 

[mm08822]

A 3/4" yellow poly NG line wont supply the need flow?

The grill uses a flexible rubber line, with a quick disconnect line, which I would remove when/if the power is lost

I would like have a generator specific line to hook up to the 3/4" yellow poly line........

Until you know the following you can not size the generator gas line and this assumes it is straight from the meter and no other loads sharing the line to the generator without additional considerations:

• generator btuh input
• gas delivery pressure
• min pressure required at gen
• length of equivalent pipe run to gen

and for the overall gas service:

• total existing load
• regulator CFM
• meter CFM

 

[theoldwizard1]

Good information, thanks.........

Looks like a power inlet box on the back of the house with a manual transfer switch might be a good idea to also consider. I would most likely need to hire someone to do this......how much could I expect this to cost?

A generator interlock kit is a type of a "manual transfer". Complete installation include the plug on the outside of the house is going to be >$500.

This is probably cheaper than those 6-8 circuit side panel generator transfer switches and it give you the flexibility to decide what circuits you want powered up. (For example, you can temporarily turn off the refrigerator and turn on the microwave.)

 

[theoldwizard1]

Gasoline is nice, because it runs for along time......but it runs out. I am still leaning towards a NG setup, because it would be very easy for me with the additional line going into my enclosed patio......and it would never run out

You can easily convert most small single cylinder gasoline engines to run on NG.

 

[4 FN 27]

Something is better than nothing. Even if it is to keep a fridge running while you figure out a more permanent long term solution.

When I built my building I had a 5K Onan portable running 2 fans and LP Heater to keep the concrete from freezing. I was going through $50.00 in gas a day running around the clock.

I finally went and bought 800 feet in extension cords and ran 2 runs of 400 feet through the woods to the building from both sides of the Panel. That cut the fuel bill but the voltage drop was terrible. Had to "push start" the big fan.

Today I am grateful I built in a Generator when we built the house. We installed an Onan 40KW unit on LP. Last night a nasty storm went through and knocked the power out. Excel Energy says it could be up to 48 hours before we have service again. This is the first time it will run for more than a couple of hours in 8 years of living in the house.

Now I have power in the house and being on a well and septic system that makes for a happy wife.

I am thinking I need to put a stand-by Generator on my building. I am going to start looking at what it will take. I have to go the 3 phase route since all my Geothermal Pumps are 480 3 phase. I have a feeling the switch gear is going to be more expensive than the Generator.

Let us know what you decide.

 

[D45]

Your grill is probably 40-50k btu. A small engine is about 10k btu per hp. My 8kw generator has a 13hp motor, so you'd be talking 2-3x the consumption of a grill.

I would not be using the grill, I would be using the supply line for the grill and doing a temp re-route to supple fuel to the generator, when/if an emergency occurs

 

[D45]

Not saying I am dead set on using NG, but it looks like LP is out

Gas is still a cheap, viable option......long burn times, especially with larger gas tanks that a lot of larger portable generators have (8+ gallons)

 

[TractorJeff]

A couple of posts are trying to tell you that the yellow natural gas line maybe physically large enough to handle your generator BUT its the pressure and flow currently delivered through this line MAYBE too low! If the line was installed for a Gas Grill it MAY be regulated in pressure only for the gas grill!

Gasoline isn't a totally bad choice but the previous poster stated 48 hours in 8 years. How do you justify storing 48 hours worth of Gasoline for that long?

As far as the CAT, it looks like a Natural Gas powered 3512 if I am not mistaken? Gas inlet pressure is less than 3psi if I remember correctly?

 

[mm08822]

A couple of posts are trying to tell you that the yellow natural gas line maybe physically large enough to handle your generator BUT its the pressure and flow currently delivered through this line MAYBE too low! If the line was installed for a Gas Grill it MAY be regulated in pressure only for the gas grill!

Gasoline isn't a totally bad choice but the previous poster stated 48 hours in 8 years. How do you justify storing 48 hours worth of Gasoline for that long?

As far as the CAT, it looks like a Natural Gas powered 3512 if I am not mistaken? Gas inlet pressure is less than 3psi if I remember correctly?

Without knowing the details required in post 31, nobody knows if the existing line is big enough.

Problem with gasoline it has a short storage life even with stabilizer. You would need to purchase fresh gas immediately for the pending need. That is still hard to predict if you will need it. It's no problem if you can consume it quickly with car, tractor, etc.
Every time you use the gas gen, you have to run/drain all the gas out of it and last thru should be gas w/stabilizer.

 

[slimcake]

Not saying I am dead set on using NG, but it looks like LP is out

Gas is still a cheap, viable option......long burn times, especially with larger gas tanks that a lot of larger portable generators have (8+ gallons)

No gas line coming out of a residential gas meter is going to have the PRESSURE to run a 10+ hp motor. I just went through all this...

 

[mm08822]

No gas line coming out of a residential gas meter is going to have the PRESSURE to run a 10+ hp motor. I just went through all this...

Not so, 20 kw Generac units require 308 CFH to run @ 5" h2o pressure. That directly converts to 27 Hp before factoring in the conversion efficiency.

Typical gas meter/regulator sizing is 250 CFH. You need to upgrade your meter and regulator to 425 CFH. This is a typical upgrade required for a ng home standby gen install.