Fedders 5000 BTU A/C test

techntrek

Re: Fedders 5000 BTU A/C test

2manytoyz wrote: »

...Warning, contains nerd content.

I believe that is true of this entire forum!

ywhic

Re: Fedders 5000 BTU A/C test

Nice video.. I like how the KW meter just shut down from overload..

2manytoyz

Re: Fedders 5000 BTU A/C test

ywhic wrote: »

Nice video.. I like how the KW meter just shut down from overload..

It actually has a switch to select what limit (2A, 5A, 10A or 15A) you'd like to set on the power strip. As long as the power surge is fast (normally is), it won't trip. But if you restart a compressor too quickly as I did, the surge is long enough to cause a trip. That's a good thing, it works!

I will mount the power strip to the small cart I built for my Yamaha generator. Sure would have been nice if these expensive generators had a digital display to see how many watts or amps they're supplying at any point. The only downside is the outlet sockets on the strip are a bit flimsy. Not sure they'll last many seasons, but will probably last a while with careful use.

http://www.p3international.com/products/consumer/p4320.html

ywhic

Re: Fedders 5000 BTU A/C test

Well Samlex tech support is abit stubborn being safe and said a 3000w inverter or a MSW inverter.. see this email..: (last message 1st)

Albert,

Unless we have the actual oscilloscope waveform of the current draw by an air conditioners / refrigerators / well pumps etc, we recommend a higher rated inverter to be on the safer side. We provide a long 2 yr warranty on our products and we would like to ensure that they do not fail prematurely due to unknown overload conditions. Further, as a Rule of Thumb, any power source should be sized at least 30% higher than the maximum power drawn

For your information, we tested “Danby” AC unit (6500 BTU) with a continuous rating of ~ 4.58 Amps. On startup, it drew over 50 Amps Peak during its start up surge and continued to draw over 40 Amps for more than 180 msec!.

Best regards

Vijay Sharma

Manager Engineering


From: A. Zeller
Sent: Friday, July 06, 2012 1:45 PM
To: Vijay Sharma
Subject: Re: Samlex/Cotek ST1500-124 Questions

Vijay,

I don't understand..

A 2000 watt inverter such as your SA-2000K-124 is rated for 2000 w continuous and 4000 w surge..

I know the A/C unit will work on a unit that is 2000 w rated as a friend of mine has done the testing..

How can the extra 2 amps for a milli-second cause a 2000 rated inverted to not make it work when its rated for 4000 w surge..

The normal running wattage for the A/C is just 500-550 watts..

Do you have a picture of the modified sine wave output from the PSE-24275A ??

Albert

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Original Message

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From: Vijay Sharma

To: 'A. Zeller'

Sent: Friday, July 06, 2012 4:08 PM

Subject: RE: Samlex/Cotek ST1500-124 Questions

Hi Albert

We do not recommend 2000 W inverter.

You may consider our cheaper 2750 W, modified Sine Wave Inverter Model PSE-24275A. Please confirm from the air conditioner manufacturer if the air-conditioner can be operated on modified sine wave

Best regards



Vijay Sharma

Manager Engineering

Samlex America, Inc.


From: A. Zeller
Sent: Friday, July 06, 2012 12:54 PM
To: Vijay Sharma
Subject: Re: Samlex/Cotek ST1500-124 Questions

Vijay,

Yes the 22.4 A is the peak amount captured on my FLUKE clamp-on meter.

Would you say a SA-2000K-124 (2000w / 4000w) model be better suited then the SA-1500-124 or PST-150S-24 model then??

Again I only want to buy once though the 3000 watt models are not within my price range.


Albert

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Original Message

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From: Vijay Sharma

To: 'A. Zeller '

Cc: 'Ken Schwantje'

Sent: Friday, July 06, 2012 3:36 PM

Subject: RE: Samlex/Cotek ST1500-124 Questions

Hi Albert

Air conditioner compressor requires very high starting surge current that may reach up to 10 times the running current depending upon the design of the compressor motor and back pressure in the condenser. The surge current will be highest as soon as the motor starts and hence, the value can be correctly recorded by oscilloscope or a meter that captures and records peak / inrush current. Please confirm if 22.4 A is the peak inrush current lasting for 1 msec. The inrush current in motor will be peak at start and will taper down to the running current in few hundred ms. Hence, an oscilloscope current graph will indicate the actual span of the inrush current.

A 1500 Watt inverter is designed to carry continuous current of 12.5 A for a resistive load and 10 A for inductive load with Power Factor of 0.8 (Motor loads normally have a Power Factor of around 0.8). The surge current rating of an inverter is normally used to size the inverter when powering Switched Mode Power Supplies that draw pulsing current of almost 3 times their RMS current. For reliability of the inverter when powering compressor based loads, we recommend that the maximum peak inrush current should be > the rated continuous current of the inverter. Hence, we recommend that our 3000 W inverter Model No. SA-3000K-124 be used for powering your air conditioner.

Please call me if you need further assistance

Best regards

Vijay Sharma

Manager Engineering

Samlex America, Inc.



From: A. Zeller
Sent: Friday, July 06, 2012 11:15 AM
To: tech@samlexamerica.com
Subject: Re: Samlex/Cotek ST1500-124 Questions

Hi,

I noticed the unit ST1500-124 is rated for 1500 watts continuous and upto 3000 surge..

Do you know if the unit could handle a 2400 watt surge for a few milliseconds??

I am trying to start an 5K BTU Air Unit and on the A/C side its giving me 22.4 amps for a mill-second (using a fluke meter) till it starts..

The running load is about 550 watts..

I also noticed the PST-150S-24 unit says 1500 and only 2000 watt surge is that correct?? It seems off..

I also noticed the SA-1500-124 unit has the same 1500 watts and 3000 watt surge as this ST1500-124 unit.. is it the same board and circuitry??

Let me know please.. I am trying to figure out which option to go with..


Al

niel

Re: Fedders 5000 BTU A/C test

yikes. either he doesn't fully know what he's talking about or it doesn't say much for their inverters.

2manytoyz

Re: Fedders 5000 BTU A/C test

Very cautious, or don't have great confidence in their product!

I've tested most of my power tools to verify if they'd work on inverter power, or on my small generator. Most everything works on either. One of the few exceptions is the air compressor. I emptied the tank to make it easier to start, and tried running it from the generator. Wouldn't start. Tried for 10 seconds before going into overload. I then plugged it into my older Xantrex Prosine 1800W inverter. It started and ran fine, albeit a little slower initially spinning up to speed than on grid power.





My generator easily starts, runs, and even restarts the 13,500 BTU A/C unit on my camper, and since my inverter has the ability to start things my generator can't, I have no doubt the inverter could easily run the RV A/C unit too. Yet they're worried about a 6500 BTU unit?

Maybe it's just me, but I'm surprised generator and inverter manufacturers don't have a huge database of the various products they've been able to run with their products... Then use that as part of the advertisement! I can't test it ALL myself!

Ralph Day

Re: Fedders 5000 BTU A/C test

"I can't test it ALL myself! "

But we all like to see you try:roll: And we all appreciate your efforts.

Ralph

ywhic

Re: Fedders 5000 BTU A/C test

It makes it hard on me as I'm the middle of the road guy at just about 2000 watts for a surge and then normal loads are all going to be way under 1500..

2-13W CFL's for 4 hours max
1-16W laptop for 3 hours max
1-50W ceiling fan for 5 hours
1-90W (max) Water pump on a pressure switch as well as a manual wall switch.
1-280w refridgerator (guessing).. and yes I know there is a surge every 20 minutes or so..

I plan on cooking via grill most summer days.. or a 700-800w microwave if needed.. I will have a hotplate rated at 1100 watts.. but I won't use that in the middle of the HOT days for sure..

2MANY.. I sent you a PM.. let me know what you think...

Cariboocoot

Re: Fedders 5000 BTU A/C test

Robert;

I find it interesting that your gen wouldn't start the compressor. What are the specs on that compressor? My Honda 2000 will start my 2 HP compressor, even on eco throttle with air in the tank. It starts slowly, then ramps up to speed.

And this, boys and girls, is why you get such non-committal answers: not all A/C, compressors, water pumps, whatever are alike, and neither are all inverters or generators! Even when they have the "same" specifications!

2manytoyz

Re: Fedders 5000 BTU A/C test

Cariboocoot wrote: »

Robert;

I find it interesting that your gen wouldn't start the compressor. What are the specs on that compressor? My Honda 2000 will start my 2 HP compressor, even on eco throttle with air in the tank. It starts slowly, then ramps up to speed.

And this, boys and girls, is why you get such non-committal answers: not all A/C, compressors, water pumps, whatever are alike, and neither are all inverters or generators! Even when they have the "same" specifications!

The Dewalt Emglo air compressor I had was rated at 15 Amp 2-3/4-Horsepower. I could have added a hard start capacitor to phase shift the power a bit, but my goal was to find the limits of my generator. I have a big DC air compressor in my truck, so making the Emglo work on portable AC power wasn't necessary.

My present generator is a Ridgid Tri-Stack. Lot more features, but even worse to start.







Not tried this one with the inverter yet. Might after I cool off a bit. HOT in my garage at the moment!

2manytoyz

Re: Fedders 5000 BTU A/C test

ywhic wrote: »

I just noticed you were testing the AC side for the surge..

Can you CLAMP the DC wire to the inverter and see what the spike was from the battery bank end of things??

[video=youtube_share;XrQzhofhnEM]http://youtu.be/XrQzhofhnEM[/video]

With a 21.5 Amp spike on the AC side, should see more than 10x that on the 12V side of the inverter. The Extech meter is obviously too slow to capture the actual peak spike. It did show 119 Amps. Didn't think that meter would be fast enough, but don't KNOW until ya try.

ywhic

Re: Fedders 5000 BTU A/C test

Thanks 2MANYTOYS..

RandomJoe

Re: Fedders 5000 BTU A/C test

ywhic wrote: »

Well Samlex tech support is abit stubborn being safe and said a 3000w inverter or a MSW inverter.. see this email..: (last message 1st)

I wonder if the issue here is that they don't *really* have a valid surge rating? I like my two Samlex inverters, but their surge ratings are just about useless - my 1500W Samlex says it's good for 3000W surge - for "less than one second". I looked at the specs and manual for the one you mentioned and they don't even have *that* line that I could find.

It was a really pleasant surprise to get my Morningstar Suresine and see its surge rating is for 15 MINUTES! :cool:

Anyway, my first Samlex was smaller and had sufficient surge rating to handle my fridge, but of course the "less than one second" wasn't enough - the inverter would trip before the fridge started. Thus why I got the 1500W one. (This before I went 48V and "real" inverters! )

ywhic

Re: Fedders 5000 BTU A/C test

At the end of the day Samlex CS is probably better than company X.. but company X's product seems to do what I intend.. run the A/C..

I don't know why they can't put out a stest sheet of different things.. or come up with max surge ratings that are real.. look at Magnum inverters.. they tell you like 1 sec, 5 sec, 1 min, 3 min, etc...

Heck even the PowerBright ones I've read about on Amz say the 2300 watt units are running A/C's...

BTW.. it happens that some of the PowerBright APS models looks just like the Samlex.. but with only 1 year warranty.. then the Go Power also mimics the numbers on the Pure Sine inverters.. someone mentioned on Amz saying the board inside says Cotek..



Vijay replied abut me asking about the Cotek, Samlex, & Go Power.... Sounds scared.. LoL..

Hi Albert

Please call me

Best regards

Vijay Sharma

Manager Engineering

Samlex America, Inc.


From: A. Zeller
Sent: Saturday, July 07, 2012 2:58 PM
To: Vijay Sharma
Subject: Re: Samlex/Cotek ST1500-124 Questions

Vijay,

I also noticed the SA-1500-124 unit has the same 1500 watts and 3000 watt surge as this ST1500-124 unit.. is it the same board and circuitry??

Also I notice GoPower has similar items as Samlex.. are they your items under there name??

Albert

techntrek

Re: Fedders 5000 BTU A/C test

Will be interested to hear the result of that call.

Dill

Re: Fedders 5000 BTU A/C test

ditto to that!!

2manytoyz

Re: Fedders 5000 BTU A/C test

Cariboocoot wrote: »

Robert;

I find it interesting that your gen wouldn't start the compressor. What are the specs on that compressor? My Honda 2000 will start my 2 HP compressor, even on eco throttle with air in the tank. It starts slowly, then ramps up to speed.

And this, boys and girls, is why you get such non-committal answers: not all A/C, compressors, water pumps, whatever are alike, and neither are all inverters or generators! Even when they have the "same" specifications!

Here's a short video of the Xantrex inverter attempting to start my air compressor.

[video=youtube_share;PRuvGx1vVT4]http://youtu.be/PRuvGx1vVT4[/video]

FWIW, this is the only thing I've found so far that wouldn't run on my inverter.

inetdog

Re: Fedders 5000 BTU A/C test

2manytoyz wrote: »

Here's a short video of the Xantrex inverter attempting to start my air compressor.

FWIW, this is the only thing I've found so far that wouldn't run on my inverter.

Was that a 69Amp inrush I saw on the meter? Wow! No surprise that neither the generator nor the inverter could handle it. Maybe a VFD???
Was the pressure tank under pressure or empty when you did the experiment?

2manytoyz

Re: Fedders 5000 BTU A/C test

Empty tank to make the start as easy as possible. Yup, 69A startup current! The compressor gave a sad little squeak, that's all!

inetdog

Re: Fedders 5000 BTU A/C test

2manytoyz wrote: »

Empty tank to make the start as easy as possible. Yup, 69A startup current! The compressor gave a sad little squeak, that's all!

Depending on the exact type of motor and starter circuit used, it may be possible, for example, to change (tune) the size of the start capacitor and/or introduce additional reactance into the start winding and get it to work. There is a thread on one of the forums (not necessarily this one, I will look for it) which goes into great detail of what is involved. Properly done it can reduce the starting inrush by a factor of two or more. But you have to know what you are doing and be willing to experiment.
There are also soft-start circuits for several hundred dollars which are not full VFDs but could help start that motor.
Using a non-inverter generator with lots of rotational inertia is another way to go.
The most economical approach is probably a smaller compressor. :-)

2manytoyz

Re: Fedders 5000 BTU A/C test

inetdog wrote: »

Depending on the exact type of motor and starter circuit used, it may be possible, for example, to change (tune) the size of the start capacitor and/or introduce additional reactance into the start winding and get it to work. There is a thread on one of the forums (not necessarily this one, I will look for it) which goes into great detail of what is involved. Properly done it can reduce the starting inrush by a factor of two or more. But you have to know what you are doing and be willing to experiment.
There are also soft-start circuits for several hundred dollars which are not full VFDs but could help start that motor.
Using a non-inverter generator with lots of rotational inertia is another way to go.
The most economical approach is probably a smaller compressor. :-)

Induction motors are notoriously hard to start. I could add a capacitor to phase shift it a bit, and it "might" start. My goal is to test the limits of my inverters and generator. The big air compressor is nice, but not necessary. I installed a 12V dual piston Q89 (45A @ 12V) in the back of my truck. I modified it by adding a small air tank, and a pressure switch. I have air at home, on the road, off the road, etc.

One more example of me living up to my handle...

[video=youtube_share;i9jEB1u8eZc]http://youtu.be/i9jEB1u8eZc[/video]

Cariboocoot

Re: Fedders 5000 BTU A/C test

What I get when starting my "2 HP" compressor (partially aired tank).
Attachment not found.
That's 10.56 peak Amps (122 Volts).
This thing runs 1285 Watts, making it a strain for a 1600- Watt generator (high elevation = less power). The compressor starts slowly.

inetdog

Re: Fedders 5000 BTU A/C test

Cariboocoot wrote: »

What I get when starting my "2 HP" compressor (partially aired tank).
That's 10.56 peak Amps (122 Volts).
This thing runs 1285 Watts, making it a strain for a 1600- Watt generator (high elevation = less power). The compressor starts slowly.

If I understand correctly, that Honda generator is inverter based, so although you have the advantage of decoupling the motor speed from the output voltage, making for better noise and economy at low loads, the presence of the inverter with its protective circuitry removes the ability of a straight rotating generator to handle a very brief peak current on momentum as well as engine power.

I had an old McCullough generator (alternator) which was nothing but a governed engine attached to great heavy rotating permanent magnet/flywheel and the output taken from the stator coils directly. The voltage regulation was poor, the frequency regulation was not great, but if the surge load did not actually stop the engine, it would bravely try to drive it.

Looked a lot like this:
Attachment not found.

Cariboocoot

Re: Fedders 5000 BTU A/C test

The EU2000i supposedly has a surge rating of 2000 Watts. And it does start the compressor, rather than fault out. It will start the "1/3 HP" water pump too (you get a nasty shock looking at the numbers on that!). I wonder how they came up with the HP rating on the compressor. Probably locked shaft draw.

EDIT: I just looked at the compressor. The label says it is a 3.5 HP! Ha! In a pig's eye! :roll:

2manytoyz

Re: Fedders 5000 BTU A/C test

The Yamaha EF2400iS will handle a 3000 Watt surge for a full ten seconds per independent testing. My testing has shown it will reliably start and restart a 13,500 BTU A/C unit, with greater than a 50A surge. The engine on this generator is the same exact size as the one used on the 2800W and 3000W Yamahas. So not surprising it has a decent startup capability.

Peak HP is a foo-foo term manufacturers use to make a wimpy motor appear big on paper. A prime example is my shop-vac. It says 5 HP. Look close, see "peak"?



The actual motor is physically rather small. Consequently, my generator, and the 1800W inverter, start/run it easily.

Now take a look at the motor on the Ridgid Tri-Stack Air Compressor:



This thing is a beast. I have big paws and the motor make's them look small by comparison.

The running current ranges from 14-14.5 Amps.



Over 1500 Watts:



So not surprised the start up current was 69 Amps!

The reason I bought this compressor is because the top section can be uncoupled from the bottom. The upper half is a compressor motor, and a small 1/2 gallon tank. The lower section is a 4 1/2 gallon tank (two 2 1/4 tanks). The upper and lower sections have their own regulators. The lower section can be charged up, disconnected, and taken to a remote area to fill up tires. This was an important feature before I added the onboard DC air compressor to my truck.



Ridgid does not talk about the actual HP rating. It is rated at 4.9 SCFM @ 90 PSI, decent enough for my needs... but not starting it with my inverters or generator!

Cariboocoot

Re: Fedders 5000 BTU A/C test

Back to air conditioning.
Numbers for the Penguin (made by DeLonghi):
11,000 btu, 115 VAC 7.2 Amps 3230 Watts

Testing:
Peak current 6.56 Amps (at 115 VAC), running current (on high) 5.72 Amps
Peak Watts 745, running Watts (on high) 649 (averaged)
Switching off the "cool jet" function drops 50 Watts
Turning the fan down to low only reduces power consumption by 10 Watts

When you consider it has 2X the cooling capacity of the Fedders that is not bad (only a bit more power used).
It'd be a monster on an off-grid system, though.

Still have to test those other two freezers for the refrigerator thread.

CDN_VT

Re: Fedders 5000 BTU A/C test

Cariboocoot
Good read ,
wish it didn't get diluted

I would like to have the time to do such , but !!
VT

2manytoyz

Re: Fedders 5000 BTU A/C test

Cariboocoot,

Those numbers are very impressive for so much more cooling capacity. If I was looking to cool more than one room during an outage with alt-power, I'd have to give that make/model a serious look. Thanks for testing and posting your numbers!