5,000btu AC unit will not run o 1,500 watt inverter. Why?

jungleexplorer wrote:

2oldman wrote:

jungleexplorer wrote:
There is some misunderstanding.

Yes, but I think we understand you. I looked up that inverter, and it's pretty cheap. Yes, cheap is not good for this application, nor is ONE battery.

This was the exact purpose of my test. To see if this inverter was up to snuff. I have done this with other inverters of the same rating with no problems. This inverter must be a piece of crapanese junk. I thought Tractor supply might have better products then Harbor Frieght. Guess not.

Buy junk at JUNK STORES for JUNK PRICES and expect BETTER JUNK?

Buy something like this..



Yeah, it can't be bought for JUNK prices but it WILL be the LAST inverter you will ever need to buy..

It is a Tripplite PV1250FC HERE for $290.

It is a INDUSTRIAL MSW 1250W inveter which IS specifically designed and built to deal with heavy INDUCTIVE loads like what a air conditioner or even a home fridge presents..

Here is some information on this inverter..

"Harness your vehicle's battery to efficiently power office equipment on the road or power tools at a work site.

Continuously supplies up to 1250 watts of 120V AC power to 2 AC outlets from any 12V battery or automotive DC source.

Frequency control locks AC output at 60Hz for operating stability of motor loads.

Includes a set of high current DC input terminals for simple, permanent installation.

Highly reliable large transformer design specializes in powering motors and other inductive loads with high-current startup needs. PowerVerter Plus Inverters accommodate "peak surge" demands by delivering more output power than their continuous rating.

Compare the "Continuous" and "Peak Surge" wattage ratings, and you'll find PowerVerter Plus Inverters supply up to double their output to easily handle equipment start up and motor cycling requirements.

A DoubleBoost feature provides up to 200% of the continuous output for up to 10 seconds, providing the extra power needed to cold start heavy-duty tools and equipment.

An OverPower feature delivers up to 150% of the continuous output for up to 1 hour. "

To sum it up, it can handle 1250W ALL DAY.

It can handle surges of 150% (1875W) for ONE HOUR!

It can handle 200% (2500W) of the rated wattage for TEN SECONDS!

None of the cheapy stuff you keep playing with will give TIME rating numbers.. Often cheap inverters will have the surge ratings of a couple of MICROSECONDS.. Which is why they are never listed.

To get a HF or a TS or any other cheapo inverter to fire your A/C unit you will need to DOUBLE the RUNNING WATTAGE..

Yeah, you will need one of those cheapo HF, TS or other import inverters that is rated around 3Kw-4KW in order to have enough snot to be able to support the start up LRA of the compressor.

2oldman wrote:

jungleexplorer wrote:
There is some misunderstanding.

Yes, but I think we understand you. I looked up that inverter, and it's pretty cheap. Yes, cheap is not good for this application, nor is ONE battery.

This was the exact purpose of my test. To see if this inverter was up to snuff. I have done this with other inverters of the same rating with no problems. This inverter must be a piece of crapanese junk. I thought Tractor supply might have better products then Harbor Frieght. Guess not.

jungleexplorer wrote:
There is some misunderstanding.

Yes, but I think we understand you. I looked up that inverter, and it's pretty cheap. Yes, cheap is not good for this application, nor is ONE battery.

jungleexplorer wrote:
There is some misunderstanding. The cables from the Batt to the inverter are 18 inch long, 2 gauge (standard automotive battery cable size). From the inverter to the TT I used a 30 foot 12/3 gauge extention cord. I have run this AC on a 100 foot 16 gauge cord before without problems.

It's not your cables, 2AWG is more than adequate for your load, the issue is the inverter, it's surge capacity is insufficient for that compressor. now, if you plug in a 1000 W toaster it will work just fine..

There is some misunderstanding. The cables from the Batt to the inverter are 18 inch long, 2 gauge (standard automotive battery cable size). From the inverter to the TT I used a 30 foot 12/3 gauge extention cord. I have run this AC on a 100 foot 16 gauge cord before without problems.

jungleexplorer wrote:
Since the unit is rated at only 515 watts and the inverter has a peak rating of 3000 watts, I find it hard to believe that the AC unit would have that steep of a start up curve..

If this is a cheap enough inverter, there's a good chance it isn't capable of the startup surge. You can try other appliances like a toaster to see what it can do.

You can read a sufficient voltage at the battery, but that doesn't mean it too cannot supply enough current. Hook it up to 4 6v batteries and some fatter cable and you'll have better chance at success.

If not, get a better inverter.

Did not see where OP was told to make sure the fridge is running op Propane or turned off.

350+ watts can make or break the deal.

Low house batteries will be another source of draw from that inverter... Would have to turn off the converter...

Run an extension cord from the inverter to the AC unit and see if it will run bypassing the TT 110vac system.

Jim

I agree not enough surge current.. But there may be a reason for that you can fix.

What size wire on the 12 volt side and how long is it.. How much batteries.

For that inverter I'd like to see at the MINIMUM one pair of GC-2, 2 pair would be better. Way better in fact.

And the wire zero gauge or bigger. 4/0 is better.

jungleexplorer wrote:
I hooked it up to my TV batter and ran a 12 gauge extention cord to my Jayco Swift TT.

As a test, will the A/C run with the same 12 gauge extension cord plugged into normal 120 volt S&B house electricity? If so you can disregard all discussion about the size of the extension cord.

If it was me the fact that the inverter did not send a "Screw This" message via smoke signals would have satisfied my curiosity. What would I gain if an FET transistor would have failed in the unit's finals? Maybe I just don't understand...