Generator Size - No BS

[Skippy38]

Ok so I just went through Hurricane Irma and was out of power for 114 hours. Generator for my house is an older Troy Bilt 3550w/20 amp output that ran enough to get me by in the house. I tried to power my 29RLI with it and it would barely cycle the compressor on the single Dometic Brisk Air II 15k a/c but it would. It would not run anything else without tripping the breaker on the generator.

So, my question is: How many watts/amps do I really need? I am thinking about getting one of the new Harbor Freight 3500w inverter generators that has a 30 amp output, but if the 3550 Troy Bilt didn't work would the HF? Is it a matter of watts or amps? Or both? The Dometic specs for my model say minimum generator size is 3.5kw. Am I over thinking this?

[B-O-B'03]

I have a Champion 3100, inverter, generator and it will run the 15K AC unit + converter & both fridges in my camper just fine.

I also use it during power outages to run the fridge & deep freeze in the garage, fridge and internet & cable boxes in the house plus a few lights.

Maybe the breaker, on the generator is bad or a problem with the generator itself?

-Brian

[Outback 325BH]

Something you need to realize is a lot/most open frame generators are 240/120 volts. That means a 3500 watt 240/120 volt generator outputs 14.5 amps on each leg. This means you only have 14.5 amps max for your camper ac unit.

Most inverter generators are just 120 volt so ALL of their rated output is available on a (the only one) leg of power. That means it is all available for your camper ac unit.


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[Skippy38]

Originally Posted by Outback 325BH

Something you need to realize is a lot/most open frame generators are 240/120 volts. That means a 3500 watt 240/120 volt generator outputs 14.5 amps on each leg. This means you only have 14.5 amps max for your camper ac unit.

Most inverter generators are just 120 volt so ALL of their rated output is available on a (the only one) leg of power. That means it is all available for your camper ac unit.


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Thanks. I was trying to step it up from one 120v 20amp regular outlet so I should have had the entire 20 amps available, correct?

[Javi]

There is a reason they put 6.5 KW gen sets in motorhomes and big 5th wheels

[notanlines]

Skippy, you are wanting a generator that won't fail you in an emergency.....and you have been through what we would all call an emergency. Please don't tell me that you would lay that at the hands of Harbor Freight. This needs to be a piece of equipment that WON'T FAIL! Step it up a couple notches.....

[Skippy38]

Originally Posted by notanlines

Skippy, you are wanting a generator that won't fail you in an emergency.....and you have been through what we would all call an emergency. Please don't tell me that you would lay that at the hands of Harbor Freight. This needs to be a piece of equipment that WON'T FAIL! Step it up a couple notches.....

Agreed. Now I just need to be certain the size that I need to power my rig.

[Racebug]

I know I can run three 15,000 BTU air conditioners with my 5500 watt onnan. I guess if all the planets align and all 3 cycle at the same time, it would trip...

[Canonman]

According to Dometic, the start up requirement for the 15k unit is between 3300 and 3500 watts hence the the 3.5 kw requirement from Dometic.
Is your XLite wired for 30 or 50 amp service? 3.5 KW @ 120v= 29 or so amps. Doesn't leave much headroom beyond starting the A/C with a 30 amp service.
Two of the 2000 watt units (pick your brand) wired together would do the job for you but I'm guessing you'd still have problems starting the A/C with any other significant loads running i.e. the microwave.

[Skippy38]

Originally Posted by Canonman

According to Dometic, the start up requirement for the 15k unit is between 3300 and 3500 watts hence the the 3.5 kw requirement from Dometic.
Is your XLite wired for 30 or 50 amp service? 3.5 KW @ 120v= 29 or so amps. Doesn't leave much headroom beyond starting the A/C with a 30 amp service.
Two of the 2000 watt units (pick your brand) wired together would do the job for you but I'm guessing you'd still have problems starting the A/C with any other significant loads running i.e. the microwave.

My 29RLI is wired for 50 amp. I am totally good with turning all coach breakers off and starting the a/c, then gradually adding circuits. I am guessing a 3500w/30amp generator in my 50 amp service coach would do the trick. I run shore power through a 15 amp breaker in my house and it never trips....

[JRTJH]

Harbor Freight Inverter Generator Warranty: "We guarantee the emissions control system on your engine will be free from defects in material and workmanship for two (2) years, provided there has been no improper maintenance, misuse, or abuse of your engine. We guarantee this product to be free from defects in materials and workmanship for 90 days from the date of purchase. Limitations apply."

Champion Inverter Generator Warranty: "CPE warrants to the original purchaser that the mechanical and
electrical components will be free of defects in material and
workmanship for a period of three years (parts and labor) from
the original date of purchase and 270 days (parts and labor) for
commercial and industrial use."

The price of the HF generator (with coupon) is $699.
The price of the Champion generator at a number of internet sites is $749.

Comparing a 90 day warranty and a 3 year warranty, I'd have to ask if the reliability of the HF generator is good enough to ignore 2.75 years of warranty???

[Skippy38]

Originally Posted by JRTJH

Harbor Freight Inverter Generator Warranty: "We guarantee the emissions control system on your engine will be free from defects in material and workmanship for two (2) years, provided there has been no improper maintenance, misuse, or abuse of your engine. We guarantee this product to be free from defects in materials and workmanship for 90 days from the date of purchase. Limitations apply."

Champion Inverter Generator Warranty: "CPE warrants to the original purchaser that the mechanical and
electrical components will be free of defects in material and
workmanship for a period of three years (parts and labor) from
the original date of purchase and 270 days (parts and labor) for
commercial and industrial use."

The price of the HF generator (with coupon) is $699.
The price of the Champion generator at a number of internet sites is $749.

Comparing a 90 day warranty and a 3 year warranty, I'd have to ask if the reliability of the HF generator is good enough to ignore 2.75 years of warranty???

I am actually just surfing around and checking out the Champion models. I think for the small price differential that Champion is the way I will go. Now how big? 3100? 3400?

[MarcS]

There's no replacement for displacement!

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[Dave W]

We have a Chinese made Boily which is rated 3600/3000. Seldom use it though it has powered the 15K Btu a/c several times on the 5er plus kept us in heat during a couple ice storms and kept the lights on during a couple nasty 'Tropical' storms like Irene and Sandy. If I were to buy a new one today, would start by considering a 3-4000 watt Yamaha or Honda then if the wallet was too thin, a Champion, all of which can easily be serviced by a local guy

[Skippy38]

Does anyone have any experience with the Northern Tool Powerhorse 3500/3000? Basically the same price as the Champion 3400/3100 and with a 2 year warranty vs the 3 year warranty from Champion...

[nellie1289]

Originally Posted by B-O-B'03

I have a Champion 3100, inverter, generator and it will run the 15K AC unit + converter & both fridges in my camper just fine.

I also use it during power outages to run the fridge & deep freeze in the garage, fridge and internet & cable boxes in the house plus a few lights.

Maybe the breaker, on the generator is bad or a problem with the generator itself?

-Brian

Same here. Great generator

[gearhead]

Generators I own:
Champion 3500.
Generac 5500 (just "sold" it to son).
B&S 3000? that I haven't even tried to start for 10+ years.

The good ones:
Two Honda 2000 inverters with IPI extended run tank.
Generac 20,000 watt whole house back up.

I chose the 2 Hondas mostly for the weight. They are less than 50# each. Before you go buy a 4,000 watt gen for your RV, make plans on how you will move it.

[skikrazee]

Originally Posted by Skippy38

My 29RLI is wired for 50 amp. I am totally good with turning all coach breakers off and starting the a/c, then gradually adding circuits.

Unless you set your A/C to the coldest setting the compressor will shut on and off based on the temperature, turning on all of the breakers after startup will only last as long as the next cycle.

FWIW, I have 2 of the Honda 2000i paralleled with a homemade 30 amp breaker even though I will only get 26.6 amps out of the gennys and I have no issues running my 15K AC, even with the econo switches turned on. I also do not turn any other breakers off.

[Dave W]

Just throwing this out as I don't have any experience yet with these - a hard start capacitor such as these, SUPCO SPP6 Relay/Capacitor Hard Start Kit. I have a couple but haven't installed them yet as we haven't had the need. Supposedly they work wonders and some reviews have reported that even 2-3K gen sets will run an a/c though I really wonder.

[Olsen29]

Micro-air easy start. I have one and run my 15000 Dometic with my 1 Honda eu2000i in eco mode.

https://youtu.be/p2K0ptvYb6Q

This explains it perfectly. The compressor can draw up to 70 amps when starting.

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