Wattage Formula

Thank you...as usual.

I have found that the initial a/c startup takes a lot more power than the run. this initial load will pop the breaker that is on the generator and you will not be running your a/c unit.

excellent video....

This is handy: Amps Volts Watts Calculator and Converter | Electricity Calculator

Well that would make me the smartest guy on this lonely country road....thank you.

OK I kind of understand.

I have a 110V , 7.7 amp 10000 BTU window unit we use only for power outages and hurricanes. The most we would run the back up AC is approximately 14 days ( CAT 1- CAT-3) . A CAT 4 will be much longer..... A CAT 5 and there will be nothing to cool off except a few pillars where the house used to be.

So, I prepare for the CAT 1-3 as those are the most common....14 days x 24 hours a day. Stopping as fuel runs out and restarting after fill up. My Honda 2500 gets 8 hours per fill up, so 4 start/stops per day x 4x14 worse case scenario.

What are your thoughts on that kind of usage?

I have two concerns that occur to me, the first is adequate wire size, you should have a #12 wire size extension cord min size, and for a long run (100ft) I would use a #10....second,

I agree with having a spare run/start capacitor and probably would even install a start kit....

...this gives a voltage boost to the compressor at start up....

....and I would check the existing capacitor with a capacitor tester to make sure it was at full strength, I've seen them weak even when new, so even check the new ones....

https://www.homedepot.com/p/Packard-440-Volt-30-5-MFD-Dual-Rated-Motor-Run-Round-Capacitor-TRCFD305/204415845?cm_mmc=Shopping%7CG%7CBase%7CAll-Products%7CAll%7CAll%7CPLA%7c71700000014585962%7c58700001236285396%7c92700010802552403&gclid=CjwKCAjw4NrpBRBsEiwAUcLcDO9-EcGmRiTKOC-962TvaC8xNhSni2kWKEieEupiTPW10cxxmK0BHxoCQFwQAvD_BwE&gclsrc=aw.ds

Slightly off-topic but... there are systems for adding an extra gasoline container to your existing generator tank. The original cap is modified or replaced with one which has no vent but has a tube which goes into another convenient fuel container. As the fuel level in the generator's tank drops, it makes a vacuum which sucks the fuel from the other tank. This way the generator could be ran non-stop by only refilling the aux. tank.

The Honda is a good little generator and well within it's limits in this application.However,if additional loads are added,the rpm and voltage and frequency will drop until the generator has time to recover.

Try to minimize starting under load.Switch off all connections until the speed has stabilized,such as after refueling,and start your heaviest load first.

This will minimize the sag in rpm and voltage/frequency.

All inductive motors are affected by voltage/frequency changes,including refrigerators,freezers,ceiling fans,etc.

It will be tempting to add additional loads,such as a refrigerator or freezer,and this can be done by staggering the usage.Let the freezer run alone for a while,then the refrigerator,ceiling fans,lights, etc.Try to minimize the total load at any given time.

Done this way,you can minimize damage to everything.

I wish you good luck and may the Lord protect you and yours in times of trouble.

AC would most probably use somewhere between 800 and 900 Watts (P = V*I = 885.5 VA)?

So, I would think you're 'good to go'.

You need to consider starting current as well. This can typically be up to 20 times full load current for the first instant and then up to 8 times FLC for a few seconds.

This could be higher if your compressor is starting with high head pressure.

The generator could struggle under those conditions.

Another point is the actual rated capacity of the generator - for instance the Honda EU20i is touted as being 2kVa and is indeed rated at 2000VA maximum, but is only 1600VA continuous. They do struggle when attempting to start non inverter type AC units on many RVs.

Gensets that have an econo cycle can also struggle if they are in that mode when the compressor attempts to start as they can't attain revs fast enough to compensate.

If you're drawing 8 times FLC for a few seconds, you have a problem, in fact your compressor is getting ready to seize...The compressor doesn't try to start against high head pressure unless it's been short-cycled, in which case it will go off on overload....Most generators have some surge capacity built in for starting motors...

A volt times an amp is a watt. So 7.7A * 115V = 885.5W. You should have no problem.

As a rule of thumb to start an induction motor the initial inrush current is 6 x the run current. Inverter air conditioners draw less current at start.

If you are starting an induction motor then the 2500W generator will struggle and may trip out or run slow on start thus dropping the frequency. If you use the 6 x current then you need a 4800va generator. I have a 5000W generator for storm damage to keep the fridge and freezer running along with water pumps and washing machines. When they all kick in together the generator loses some speed but rapidly recovers.

Check that the 2500W is not a peak load rating or that the 2500 is actually W not VA.

why don't you operate and let us know?

a 2500 watt generator is actually a 2000 watt generator, and a lot of times, that is actually split between two outlets so drop it to 1000 watts.

then there is a loss due to the cord length that you connect it to. Make sure you use the same length that you will be using during the emergency.

now there is the huge surge that the compressor start up will (my bet) pop the breaker since the amperage is split in half between the two outlets.

these generators are always overly stated as to the actual power. don't forget to ground the unit. buying a flex-pipe and using an auto muffler is a good idea too since there are people trolling down streets at night listening for generators. the best scam I have heard of: the perp takes the homeowners lawnmower, start it up and then steals the generator. homeowner hears the motor running during the night and thinks all is well only to find his generator gone and his mower running. very common after hurricanes.

my generator of choice is from army surplus: MEP003 10KV (actually 12.5KW), this baby also runs at only 1800 rpm so will use less fuel than the 2800-3000 rpm units.

oh and its EMP proof to boot!

I found one for $350.

https://greenmountaingenerators.com/product/mep003a-10kw-military-diesel-generator/

$350 dollars!Wow!What a deal.I checked the link you provided,but nothing close to that price.

I realize this is not the best time of year to buy a generator,but at that price I will take a dozen.

The gov. surplus site used to be a good place to find surplus generators,but large companies like Green Mountain are apparently buying them up as soon as available.

No fault of theirs,but I do miss the opportunity of good deals that used to be available.

One thing I might add about the A/C.

Make sure the evaporator(inside)coil and the Condenser( outside ) coils are clean.

They may look clean,but have a film that will reduce efficiency.

Get some no rinse coil cleaner and follow directions.Also check for bent fins on the coils,and straighten them with a screwdriver, if possible.If there are a lot of them,buy a coil comb kit that has combs spaced for nearly all coil fins.

A good way to clean a portable window units is a pressure washer,but be careful to keep the stream in line with the coil fins or they will bend.Just don't direct the water directly at the motors or electrical controls.

https://www.amazon.com/HonsCreat-Conditioner-Radiator-Condenser-Straightener/dp/B077K2KCJ2/ref=sr_1_7?crid=335KAPNQDSUB5&keywords=coil+comb+for+air+conditioner&qid=1563981732&s=gateway&sprefix=coil+comb%2Caps%2C175&sr=8-7

Also buy a few evaporator filters for spares.If the filters are dirty,they can seriously lower efficiency.

These suggestions will give you more cooling for the same amount of energy,and make your unit last longer.

I can't think of a faster way to ruin the coils on an AC unit than to put a pressure sprayer to it....

As I stated,if not careful,you can bend the fins on the coils.

I have cleaned many units this way,and I have learned how to do it harmlessly.

It is not a steep learning curve.

In the event that some fins are bent,I use a coil comb to straighten them.

I use a Robinair 18403 Fin Straightener,but there are many other brands.

I have seldom seen a package unit,split system, or window unit without some bent fins.

Do not hold the nozzle too close to the coils and be careful of the direction of the water stream.

As for faster ways to destroy the coils:A lawn mower throwing projectiles at them, a kid bumping into them, an errant basketball or softball,careless handling during installation, a bicycle out of control, a BB gun or pellet gun,and my favorite slow-death of coils is dogs urinating on them.

Once one dog does it,they all stake their claim to the ice water dripping out,and every dog passing by has to try to outdo the previous one by aiming higher.

(Kinda like men,the first liar doesn't stand a chance)

A window unit is not usually subjected to those problems...Using a pressure sprayer on a coil is like driving a 1" finishing nail home with a sledgehammer....

The skill of the operator is the biggest factor.

Any tool can cause damage if improperly used.

And yes,window unit coils are sometimes damaged by mishandling during installation,stray BB's and lawn mower debris.I am describing incidents I have seen.

Window units are not subject to dog urine,(unless it is a very tall dog).

I feel comfortable using a pressure washer to clean coils, and have cleaned hundreds when I worked for an AC servicing company as a young man(Many moons ago) and have not destroyed one yet.I still clean my own that way.

Just lucky I guess.

A person should know his own skill set,and use common sense.

We must be talking about two different types of pressure washers....I'm talking about one of these...

If you subjected the soft aluminum fins on an AC coil to this kind of force it would probably rip the fins right off the tubing, no matter what the angle of attack....unless you were standing back about 10'...I have never seen anybody in my 40 years experience take a pressure washer to a coil...and I've been around...no AC service van even carries a pressure washer,, that I've ever seen...

A high pressure washer will also remove paint from a car if improperly used.

Use a tip that gives a flat pattern, not a round or oscillating one and use common sense with distance and angle.

No thanks, I'll stick with a hose and nozzle, much easier to set up and handle, and it works quite well...You can destroy a thousand dollar coil screwing around trying to prove something if you like, but not me...I was never that stupid....and that's saying something...haha

A/C is nice, but your refrigerator is a necessity. I doubt this genset can handle both. While the fridge doesn't draw as much, it can suffer the same failures as the folks above mentioned to the A/C. In addition, the fridge enters a defrost cycle approx every 8 hours. You might be able to get by using the A/C at night, while unplugging the fridge and then running the fridge during the day. A.A.R. these are not continuous duty units, running them 16 hrs a day is going to be tight. I would pick up another unit, this can be noisy and use it during the day. I've seen 4500 continuous watts units for under $400. My 3800 watt B&S burned an exhaust valve, took 5 wks to get a replacement. (I bought it in 2010, but it has a 2004 engine.) I now have a spare head and torque wrench, I can change it in under 90 minutes. You might wonder how I know all this interesting stuff. Irma and Maria. Couldn't even get to CR4 to ask for help.......no internet.

Just a reminder, Coffee Pots and Hair Dryers are surprisingly large loads.

WOW this is a lot of information.

The genset is 4 feet from the AC

I'm using NO. 12 wire x 8 feet of cord.

I will NOT run anything off this genset while the AC is running.

We can live on my double industrial fan set up as long as the humidity is reasonable .

I want to install a Hard Start on my 5 ton Central and my gen set.

Thank everybody....I'll run it and see what happens...and post the results, but first I want install the HARD STARTs.

That little Honda Generator will not run that 5ton unit. Of course you knew that.