Inverter not delivering within specs: It is a surprise?

[djm45]

I have a GoWISE Power 1500W Pure Sine Wave Power Inverter (with peak 2000W draw). I assumed that with a 1500W continuous draw specification that I would be able to use a 10 amp device at 125V on the inverter. However, the moment I turn on the device, the inverter shuts down. Actually, I am using a DeWalt 10 amp vacuum for tidy up my shed space. Well, that's my intent. Is this one of those devices that cannot be powered by solar? I assume the expected 1250 amp draw would work since the peak draw was at 2000W. Am I overlooking something obvious? Is the 10 amp label on the DeWalt not accurate?

Thanks for any insights!

 

[HighTechLab]

What size battery cables are you using and what batteries?

 

[Mattb4]

Vacuum cleaners have a very high start current. You likely could not power it with a 2000w rated inverter. When I start my Ridgid 8.3a vacuum off my 3kw AIO inverter it handles it but I can see the surge current jumping above the 3000w briefly.

I would guess you need a low frequency inverter or a much higher rated HF inverter if you intend to run the Vac.

 

[djm45]

Two BougeRV 100Ah 12v LiFePO4 batteries with 2AWG cables (less than 12 inches total length to inverter).

 

[djm45]

Vacuum cleaners have a very high start current. You likely could not power it with a 2000w rated inverter. When I start my Ridgid 8.3a vacuum off my 3kw AIO inverter it handles it but I can see the surge current jumping above the 3000w briefly.

I would guess you need a low frequency inverter or a much higher rated HF inverter if you intend to run the Vac.

I wondered if the start up drain was a problem, but I couldn't measure the watt draw before. I now have a watt meter so I can check out if a surge is more than (I) expected.

 

[Solar Guppy]

All motors that are not variable speed have a significant surge when first turned on, typically 3-4x the nameplate rating, this is also known as locked rotor amps.

 

[djm45]

I just measured the watt draw on the vacuum. It runs continuously just over 1000W. The startup surge is about 1700W which flashes once and then drops down. However, I do not know the response time of my watt meter. But the surge could be enough to disturb my inverters. But if the surge is actually 3 - 4X, it's clearly out of the ballpark. That's a new term for me: "locked rotor amps". Good to know. Thanks!

 

[MrM1]

I wondered if the start up drain was a problem, but I couldn't measure the watt draw before. I now have a watt meter so I can check out if a surge is more than (I) expected.

A watts meter will not be fast enough to to pick up motor surge. It's measured in milliseconds.

You need a good digital volt meter with In-Rush function.

 

[MrM1]

My 3/4 horse power well pump runs on 8 amps (4 amps on L1 and 4 on L2),. But my measured start up is 42 amps per leg.

 

[pollenface]

The inverter is not big enough. If you multiply the continuous rating by 5-6x it will give you a better idea of the surge capacity required.

A watts meter will not be fast enough to to pick up motor surge. It's measured in milliseconds.

You need a good digital volt meter with In-Rush function.

What he said

 

[JRH]

A watts meter will not be fast enough to to pick up motor surge. It's measured in milliseconds.

You need a good digital volt meter with In-Rush function.

Your correct…I bought a volt meter device that was inrush rated to 2000 amps ac/dc…+ a lot of other stuff…while I have no idea how or why to use most of its functions beyond the normal simple things ya need in life , I did test out the inrush feature …WOW. It’s amazing how much and how quick so many things draw wayyy more power than is reflected by my other testing stuff or display panels…try your ac unit or a good sized pump… haaaa…no wonder things trip …. Most stuff never even show the surge/ drop that occurs …
its pretty cool to play with……
One day I’m Gona study the manual and figure out what it can really do..

 

[HighTechLab]

I would double check that you get a solid 12 or more volts on the DC input terminals of the inverter when you start the load and the inverter shuts down.

Far too often budget batteries from overseas suppliers give the impression that they are working but then fall flat on their face when presented with a real load. Before changing any parts, it's a very good idea to double check that the ones you have are doing what they should be. There is a very good chance that only one battery is working and the moment you go over 1200w (the limit of the one working battery), the BMS shuts down on overcurrent protection.

 

[MrM1]

I would double check that you get a solid 12 or more volts on the DC input terminals of the inverter when you start the load and the inverter shuts down.

Far too often budget batteries from overseas suppliers give the impression that they are working but then fall flat on their face when presented with a real load. Before changing any parts, it's a very good idea to double check that the ones you have are doing what they should be. There is a very good chance that only one battery is working and the moment you go over 1200w (the limit of the one working battery), the BMS shuts down on overcurrent protection.

Or This ^^

 

[Mattb4]

I would double check that you get a solid 12 or more volts on the DC input terminals of the inverter when you start the load and the inverter shuts down.

Far too often budget batteries from overseas suppliers give the impression that they are working but then fall flat on their face when presented with a real load. Before changing any parts, it's a very good idea to double check that the ones you have are doing what they should be. There is a very good chance that only one battery is working and the moment you go over 1200w (the limit of the one working battery), the BMS shuts down on overcurrent protection.

If the inverter has any display it might give a fault indication for overload or if it is low voltage. Overload would be due to excessive start up current. Low voltage would indicate a problem with battery.

 

[mdkhairulanwar86]

I have a GoWISE Power 1500W Pure Sine Wave Power Inverter (with peak 2000W draw). I assumed that with a 1500W continuous draw specification that I would be able to use a 10 amp device at 125V on the inverter. However, the moment I turn on the device, the inverter shuts down. Actually, I am using a DeWalt 10 amp vacuum for tidy up my shed space. Well, that's my intent. Is this one of those devices that cannot be powered by solar? I assume the expected 1250 amp draw would work since the peak draw was at 2000W. Am I overlooking something obvious? Is the 10 amp label on the DeWalt not accurate?

Thanks for any insights!

you must check efficency also. if 1500w x 95% via battery mean max 1425w / 11.4A (125V). obviously more than rated. 2000W peak only few miliseconds.

 

[Whats-n-Watts]

Millisecond amp draw (surge) could be 3 time that much. Older appliances are the worst about that among other negatives. I size mine by multiply sticker amp x volts then multiply that by 1.75 and round to the upper side of that.

10a x 120v = 1200 x 1.75 = 2100 therefore 2,500 watt inverter to know I am covered.

 

[Rocketman]

There is a chance that the inverter is dropping because of low voltage- you could try either double up the cables 2x#2 for positive and negative or go with much thicker cables like a 2/0. That may help - and may not.

The other issue is your inverter is a high frequency inverter. They do not have much - if any - surge. A low frequency inverter is much better - but they are heavier and cost more.

 

[Whats-n-Watts]

There is a chance that the inverter is dropping because of low voltage- you could try either double up the cables 2x#2 for positive and negative or go with much thicker cables like a 2/0. That may help - and may not.

The other issue is your inverter is a high frequency inverter. They do not have much - if any - surge. A low frequency inverter is much better - but they are heavier and cost more.

That too!

 

[time2roll]

Generally the shutdown error will be overload or low input voltage. Check the input voltage right on the inverter terminals at start up.
Any chance the inverter indicates the shutdown error?

 

[HighTechLab]

Hope you guys realize this thread was started in May and was dead until yesterday. The original poster has not been active on this forum in over a month. I'm certain the original poster has solved their problem by now.