Large motors and powertools on hybrid inverter

[Pink7]

Is there any reason to not run power greedy applications like a rice machine and power tools on solar power from hybrid inverter? Im getting 7k watt or so middle of day and our rice machine uses 3kw or so (4hp)?

 

Pink

[KhunLA]

52 minutes ago, Pink7 said:

Is there any reason to not run power greedy applications like a rice machine and power tools on solar power from hybrid inverter? Im getting 7k watt or so middle of day and our rice machine uses 3kw or so (4hp)?

 

Pink

As long as you don't go over your inverter's output, should be fine.  Just make sure others know your running it.  Someone turns on AC, someone else hops in the shower, then someone in the kitchen turns on the oven or pops something in the microwave ... oops

 

And yes, I actually did it once.  Forgot car was charging.  ACs on, baking break, I think I'll take a shower (3.5) ... oops.  Took couple minutes to reset itself.

[impulse]

May work.  May not. 

 

Typical inrush (starting) current on electric motors can be 5-7 times the actual running current.  On an old timey diesel generator, you'd hear the generator lugging and slowing down just a bit, then back to normal after the motor is started.  Modern inverters just won't put out over their design amps.  And if you feed your rice machine less amps than required to start, it may not.  

 

Inrush only lasts a fraction of a second, and if the motor does start, it'll run fine.  But some motors just won't start.  Also depends on whether it's got a capacitor starting it, or just across the line and single vs 3 phase. 

 

If you posted the nameplate from the rice machine motor, it may have more info.  And the nameplate from your inverter.

 

[Pink7]

2 minutes ago, impulse said:

May work.  May not. 

 

Typical inrush (starting) current on electric motors can be 5-7 times the actual running current.  On an old timey diesel generator, you'd hear the generator lugging and slowing down just a bit, then back to normal after the motor is started.  Modern inverters just won't put out over their design amps.  And if you feed your rice machine less amps than required to start, it may not.  

 

Inrush only lasts a fraction of a second, and if the motor does start, it'll run fine.  But some motors just won't start.  Also depends on whether it's got a capacitor starting it, or just across the line and single vs 3 phase. 

 

If you posted the nameplate from the rice machine motor, it may have more info.  And the nameplate from your inverter.

 

Ok thanks for that info. My garage have grid supply so i just connect it there then to avoid any issues.

 

Pink

[Muhendis]

54 minutes ago, Pink7 said:

Ok thanks for that info. My garage have grid supply so i just connect it there then to avoid any issues.

 

Pink

That's the safest way.

I also have a rice mill but only a single phase 2.2 kW motor. That's 10 amps running.

My 8kW inverter is OK with that but, as has been said, startup current will see a short lived 50A or more burst which is 11kW or more.

That's ok if the motor starts off load. The inverter will handle it. Trouble is, there have been a few occasions when things go wrong and the motor stalls. In those conditions the current is limited only by the resistance of the motor winding and that current is really high.

I always switch over on my ATS to GEC (Greedy Electric Company) when milling.

Edited October 6, 2023 by Muhendis

[Crossy]

Check the manual of your inverter, many are actually grid-sync and will top up solar with the grid whilst still using what solar is available. Others will simply go into bypass mode.

 

Of course, both these modes have a limit.

 

 

[lom]

14 hours ago, Muhendis said:

I always switch over on my ATS to GEC (Greedy Electric Company) when milling.

That's my default ATS input position (A, grid) and there the inverter will produce as much as the house consumes up to the inverter limit after which any additional power needed is taken from the grid.

The other ATS input (B) is the backup load output from the inverter.

When there is power available on both A and B inputs then input A has priority.

 

Edited October 7, 2023 by lom

[Muhendis]

21 minutes ago, lom said:

That's my default ATS input position (A, grid) and there the inverter will produce as much as the house consumes up to the inverter limit after which any additional power needed is taken from the grid.

The other ATS input (B) is the backup load output from the inverter.

When there is power available on both A and B inputs then input A has priority.

 

I have my ATS set as follows.

 

N Primary = Solar inverter

R Backup = Grid

 

Reasoning is that my house is completely solar powered but if batteries are too low at night then inverter will switch off 'till batteries are good again and ATS will switch over to GEC. Once the batteries are back up to something like full then the ATS will switch back to inverter output. I should point out that this condition has never happened in the 13 years I have been solarised. 

The ATS gets tested every time I grind my rice. I simply switch off/isolate the inverter output and over goes the ATS to grid supply. To revert to normal solar power I simply switch on/un-isolate the inverter.

[lom]

57 minutes ago, Muhendis said:

Reasoning is that my house is completely solar powered but if batteries are too low at night then inverter will switch off 'till batteries are good again and ATS will switch over to GEC.

There's our difference, if my batteries are too low at night then the inverter will use the grid instead until battery got enough charge from the panels in the morning.

My ATS is a switch between on-grid and off-grid modes and switches only at grid blackout.

[Pink7]

On 10/7/2023 at 12:15 PM, Muhendis said:

Reasoning is that my house is completely solar powered but if batteries are too low at night then inverter will switch off 'till batteries are good again and ATS will switch over to GEC. Once the batteries are back up to something like full then the ATS will switch back to inverter output. I should point out that this condition has never happened in the 13 years

I was surprised today to see that i got quite good level of solar power even in a light raining, cloudy day. At 14.15 my batteries was recharged, so Im exited how long i can keep running without my ATS kicking inn.

 

Pink

 

Pink