Drier Startup Issue

[WildernessGuy]

Hello,

I have an off-grid home with a small generator and solar w/battery setup.

Recently, I bought a new Amana LP clothes dryer.

Issue: When I start the dryer the initial draw causes either the inverter to trip (when on battery power) or when on generator power it causes a low moan (for lack of a better word) and then turns off.

I brought in my portable jobsite Yamaha 7200 generator - and tested and the Amana fires right up. I noted from the sound of the portable that it revved up substantially as the dryer was started and then the generator went back into a normal rev.

The inverter is 3,200 watts - runs everything I need with the exception of my well. My normal generator is an old LP (which could be replaced but it runs the battery charger and LED lights, and an old washing machine just fine).

Since it seems the motor's starting is my problem, could a guy put a starting capacitor in to address the need for the initial boost?

 

[Delta Prime]

could a guy put a starting capacitor in to address the need for the initial boost?

How many guys does it take to screw in a lightbulb?
"0"because the light bulb works, it doesn't need replacing.
I think it's time for an upgrade to your battery backup and a beefier generator. Sounds to me like your system is it need of greater current capacity, that's why it's tripping breakers,

 

[Bluejets]

As quoted in another post today, motors draw 4 to 6 times full load current at startup.
You will not modify anything to avoid that.
Seems more than your "small generator" can handle.

 

[danadak]

Why not use a super cap battery bank on input side of inverter ?

Amazon.com : super capacitor board

Not a designer in this area, so I may be way off base.

Can you capture a graph of startup current and V when on Yamaha
gen ? Could do with Arduino to make a DAQ based logger. Then you
have design parameters to work with.

If system is 12V into inverter use a starter battery pack possibly, as
that will supply some serious power for 10+ secs. Note not sure
what its V looks like when doing that, eg. affect on inverter.

Amazon.com : battery jump starter

Regards, Dana.

 

[Bluejets]

It's the inverter itself with it's design "restrictions" that become the problem trying to start motors.
As the Op quoted, it may well be a 3200w rating while fine for resistive load (if the rating can be believed initially) but that means didly squat when trying to start a motor at 4 to 6 times it's full load current.
Simply will not work.

This "argument" if you like goes back yonk years to when construction site carpenters and the like would try to run 1.5hp compressors wound up to 130psi on 50ft long leads off 7kva generators and wonder why the gensets would cook and/or the compressor motors and blow motor start caps like you wouldn't believe..
A small degree of relief when "unloaders" came on the market but generally same problems.

 

[WildernessGuy]

I really appreciate everyone's input here. Of all my motors: washing machine, well pump, septic trash pump, and circular saws, it is just so weird to my layman's brain that a new, LP, drier's motor is the one that cannot start. The old rusted out 14 year old LP drier this new one replaced worked just fine as well. ~Thanks again for your thoughts on this.

 

[WildernessGuy]

Why not use a super cap battery bank on input side of inverter ?

Amazon.com : super capacitor board

Not a designer in this area, so I may be way off base.

Can you capture a graph of startup current and V when on Yamaha
gen ? Could do with Arduino to make a DAQ based logger. Then you
have design parameters to work with.

If system is 12V into inverter use a starter battery pack possibly, as
that will supply some serious power for 10+ secs. Note not sure
what its V looks like when doing that, eg. affect on inverter.

Amazon.com : battery jump starter

Regards, Dana.

I'll see if I can get a capture. Would be nice to know what the heck this thing is drawing.

 

[danadak]

For current and voltage you want isolation measurement for safety.

https://www.ti.com/lit/slyy154

Regards, Dana.