Chip bin costs 6 amps?

B

Bob Miller

Guest
Got my cyclone mostly setup, just waiting on S&D fittings to finish running the duct work. Following Bill's suggestion I took amp meter readings for maximum blower/cyclone amps (19.8), minimum blower/cyclone amps (8.8). The maximum was taken with the cyclone attached but all openings left open. The minimum was take with the cyclone transition and the dust bin connector openings blocked.

So far so good. I then took a reading with the filter stack added and got 19.1. Again this seems about right.

Now the part the worries me. When I attach the chip bin the amps goes down to 12.8. Also, the suction on the chip bin is so great that the bin is lifted off the floor about 5 inches and the sides of the can get sucked in in a couple of places. The chip bin is a metal 33 gallon trash can with a 6" opening cut into the lid connected to the cyclone with 20" of 6" flex hose. Is this "normal"? I'm worried for two reasons. 1.) 6 amps of lost air flow at the trash can is 6 amps of air flow I won't have at the machines. 2.) With this much suction at the bin how will any "fine dust" drop out into the chip bin?

The final amp reading I took was with the chip bin and filter stack hooked up and the cyclone transition blocked. With this setup I got 8.8 amps. Same as the minimum blower/cyclone amps. This means I don't have any leaks in the chip bin setup.
 
Bob,
12.8 amps is lower than I've seen. My system with the 14" impeller measures 16 amps with the gates open and I measured the voltage right at 229 V. If your voltage is running high the amps will be low. I had one customer call me to tell me he measured his current at 14.5 amps. I told him to check the voltage. He e-mailed me back and said it measured 247 Volts. So, that would be my starting point. Check the voltage. If it is close to 230 V then I would say there is something wrong. Keep us posted.

Ed
 
Ed,

Thanks for the reply. I measure 128 volts AC across each leg, yielding 138 volts total. So, my voltage is in the "normal" range. All the amp readings I've collected look normal until I connect up the dust bin. That's why I send the note looking for input to see if this was normal.

I have a left hand cyclone and from pictures in the gallery I noticed that you have a right handed model. I remember reading on Bill's site that having the cyclone spin the air in the opposite direction of the blower would eat some amps. Today I found were I read this again and Bill claims that the cost is about .25 amps. Not very much. And because a left hand cyclone spins the air in the same direction as the blower my cyclone should be the more effient version. So, I'm even more confused about where my amps are going. Thanks again for your help.
 
Ed,

Never do" higher" math at night. 128 * 2 is not 138. The 100 was a typo, but the 38? So, with 128 * 2 = 256 that changes things. My Volts/Amps is 256 / 12.8 = 20. Your Volts/Amps is 229 / 16 = 14.3. I know this isn't the right way to compare, but in order to compute horse power I would need t the the motor's Efficiency and Power Factor. But for the same motor (Leeson 20.8 amp) the Efficiency and Power Factor should be a constant. So, my system without all the ducting of yours is doing more work. I'm sure when I get the ducting added my numbers should fall in line with yours.

Ed, thanks for pointing me in the right direction.
 
Bob,
Just to be sure, set your volt meter on a higher range and check across the two hot leads. This will give you a measured voltage to work with. It might not be double the individual readings.......has to do with the two legs being out of phase with each other. Measure it that way and let me know what it is. It is my understanding that a utility company is supposed to keep the voltage with in a + or- 10% so it should range from 220 + 22 = 242 to 220 -22 = 198.
I didn't answer this before
The trash can has a lot of suction on it. Mine gets sucked off the ground too when it's empty. The vacuum in these systems is measured it inches of water, but converting it to lbs/sq in you come up with about 1/2 per sq in. That isn't much, but that's 72#/sq ft. If you have 6 sq ft of area around the trash can it's getting pulled in with 452# of force - applied evenly of course. The lid would have about 2 sq ft of area, so it's getting pushed down with about 140# of force.

Ed
 
Ed,

Just measured the voltage across both hot legs. I got 258. It's showing 129 on each of the legs.

Just a quick test I connected a 7 foot piece of flex hose to the inlet and sucked up some dirt. That worked great. Went into the cyclone just fine but a bunch of the dirt didn't fall into the dust bin. It just raced around the inside of the cyclone until the power was turned off.

Just for grins I added 20 feet of 6" S&D onto the flex hose and took another amp reading. The system was measuring 12.4 amps. So, 7' of flex with 2 90 degree turns and 20' of S&D costs about .4 amps.
 
Bob,
Product staying in the cyclone seems to be part of the nature of the beast if you will. Mine does the same thing. It seems that as long as there is product going in that it will go around in a spiral until it reaches the bottom. It's only at the end when there isn't anything else coming in that the last little bit will start swirling around. The product will fall if you close off the intake or turn off the cyclone. Now, if you had a metal cyclone you'd never know this was happening.

Ed
 
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