DC motor honey extractor

[Willwinn]

Hi,
I'm looking at making my honey extractor in an unpowered shed. The extractor I want to put in there is a Lyson 20 frame (https://www.betterbee.com/extracting/lyson216-20m.asp).
It has a 1/3 hp dc motor.
My question is how do I estimate the power requirements?
Thanks,
Will

 

[Q-Dog]

Call the distributor and ask them?

 

[fafrd]

Hi,
I'm looking at making my honey extractor in an unpowered shed. The extractor I want to put in there is a Lyson 20 frame (https://www.betterbee.com/extracting/lyson216-20m.asp).
It has a 1/3 hp dc motor.
My question is how do I estimate the power requirements?
Thanks,
Will

1 horsepower is 745.7Watts, so your 1/3hp motor should need less than 250W sustained (though close to 1.5kW of startup-surge)...

 

[svetz]

From the description it's a 120V device using PWM to run a variable speed DC motor. Since it's AC, you'll need an inverter to convert DC power to AC if you want to run it off battery.

If that's what you want to do, we can somewhat estimate this, but you also need to know how long you'll run it for. For example, let's assume the motor is running about 70% of @fafrd estimate (it's a variable speed, has a mechanical linkage, an honey is viscous), so...

250 Watts / .7 eff = 360 Watts​

The electronics in the "brain" will consume energy too, but we don't know how much... so let's guess 40 watts for 400 watts of AC power.

Now let's say the inverter is 90% efficient:

400 Watts AC / .90 AC/DC = 445 watts DC.​

Let's say you run it for 90 minutes a day

445 watts x 1.5 hrs / day = 670 watt-hours/day.​

Let say you want to run if off a 12V battery, how many amp-hours would you need?

670 Wh / 12 V = 56 Ah​

Let's say it's a lead acid battery and to increase the battery life you want to keep the depth of discharge above 50%, so 56 Ah / .5 = 112 Ah. Then there's Peukert's Law to overcome, since you're draining a battery in 90 minutes rather than 20 hours it would be pretty high, to know for sure you'd have to see the batteries datasheet, usually it's around 50% for such a rapid draw so 112 Ah / .5 = 224 Ah. If you're using lithium instead of lead acid move the depth of discharge to 80% and the Peukert effect to 95% (about 74 Ah).

Considering these are guesses the calculations could be way off. But, hope that walking through the math helps you out.

 

[Willwinn]

From the description it's a 120V device using PWM to run a variable speed DC motor. Since it's AC, you'll need an inverter to convert DC power to AC if you want to run it off battery.

If that's what you want to do, we can somewhat estimate this, but you also need to know how long you'll run it for. For example, let's assume the motor is running about 70% of @fafrd estimate (it's a variable speed, has a mechanical linkage, an honey is viscous), so...

250 Watts / .7 eff = 360 Watts​

The electronics in the "brain" will consume energy too, but we don't know how much... so let's guess 40 watts for 400 watts of AC power.

Now let's say the inverter is 90% efficient:

400 Watts AC / .90 AC/DC = 445 watts DC.​

Let's say you run it for 90 minutes a day

445 watts x 1.5 hrs / day = 670 watt-hours/day.​

Let say you want to run if off a 12V battery, how many amp-hours would you need?

670 Wh / 12 V = 56 Ah​

Let's say it's a lead acid battery and to increase the battery life you want to keep the depth of discharge above 50%, so 56 Ah / .5 = 112 Ah. Then there's Peukert's Law to overcome, since you're draining a battery in 90 minutes rather than 20 hours it would be pretty high, to know for sure you'd have to see the batteries datasheet, usually it's around 50% for such a rapid draw so 112 Ah / .5 = 224 Ah. If you're using lithium instead of lead acid move the depth of discharge to 80% and the Peukert effect to 95% (about 74 Ah).

Considering these are guesses the calculations could be way off. But, hope that walking through the math helps you out.

Thanks for the explanation. But this extractor can be run on 12 volts. I'm guessing that would be more efficient than the inverter and would save about 45 watts.
I'm trying to estimate the cost of a solar off-grid shed vs. adding a sub panel from the house. Tying into the house seems to be less expensive.

 

[svetz]

If it's designed to be run off 12V; the seller might know how many amp-hours it needs.

Going from the house might be less expensive, but be careful of voltage drop on long runs. Good news is the site said it could run on 110V. So, if your house is around 120/240 (that's the standard, but usually a home in U.S. ranges around 116 to 124V, for example my outlets measure 122.4V) you might be able to support a 10V drop for the distance. A voltage drop calculator will help with this.

You can calculate the costs to go solar with the energy requirements. If you only run it around noon on clear days you probably won't need much in the way of a battery, just something with a high enough C-Rate to cover the surge current when it starts up. 445 W is probably only around two 300 Watt panels depending on where you live. There's a bunch of example calculations in the FAQ section for that, but if you need help just holler.

 

[gecko]

I'm an old school keeper. Feral bees, foundtionless comb honey, crush and drain and a solar wax melter!