ptonsparky
Tom
- Occupation
- EC - retired
I am monitoring the 7.5 for power.
I will need to climb the leg and walk the plank, again.
I will need to climb the leg and walk the plank, again.
Last edited:
HP swap (Horsepower)
- Thread starter ptonsparky
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gar
Senior Member
- Location
- Ann Arbor, Michigan
- Occupation
- EE
141012-0831 EDT
Change the power monitor full scale to 10 HP and make your scaling for full scale = 7457 W. Use what I outlined in a previous post to create your power limits.
On the other hand if you do not want to run the 7.5 HP motor above about 5 HP, then leave the power monitor on the 7.5 HP range.
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Change the power monitor full scale to 10 HP and make your scaling for full scale = 7457 W. Use what I outlined in a previous post to create your power limits.
On the other hand if you do not want to run the 7.5 HP motor above about 5 HP, then leave the power monitor on the 7.5 HP range.
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gar
Senior Member
- Location
- Ann Arbor, Michigan
- Occupation
- EE
141012-2134 EDT
My latest thought. I believe you have said that the 7.5 HP motor where the power monitor is installed is not loaded to its maximum.
Thus, leave the power monitor scaling set to the 7.5 HP range. Run an experiment while monitoring power by loading that part of the system with the maximum amount of product (probably most moisture content) and at the maximum flow (speed) that is required, and see how the power input compares with the selected power monitoring range. If adequately within the power meter range, then don't change scaling.
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My latest thought. I believe you have said that the 7.5 HP motor where the power monitor is installed is not loaded to its maximum.
Thus, leave the power monitor scaling set to the 7.5 HP range. Run an experiment while monitoring power by loading that part of the system with the maximum amount of product (probably most moisture content) and at the maximum flow (speed) that is required, and see how the power input compares with the selected power monitoring range. If adequately within the power meter range, then don't change scaling.
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mike_kilroy
Senior Member
- Location
- United States
I just stumbled across this. I know you guys have been going hot and heavy about corn drying and loads and such, and I do not want to get in the middle of that any which way.
Of course if one can measure power instead of current for such a question it would be nice and give more info. But I wonder why one cannot believe their clamp on ammeter?
Sure, real watts is good to know, but when folks who manufacture motors list a rated continuous current value on their nameplate, are we not allowed to believe i
mike_kilroy
Senior Member
- Location
- United States
posted in middle of type.... cntinuing where cut off above....
not allowed to believe it is the truth?
If a nameplate says it can handle 7.6amps and our clamp on meter shows 5.1amps at worst case load, why can't we simply say "this is ok and this motor will do the job?"
Sure, as engineers, we like to know what the no load watts, kva, current is compared to the loaded same values, but what difference does it make at the end of the day?
Indeed, 'what are we missing?"
not allowed to believe it is the truth?
If a nameplate says it can handle 7.6amps and our clamp on meter shows 5.1amps at worst case load, why can't we simply say "this is ok and this motor will do the job?"
Sure, as engineers, we like to know what the no load watts, kva, current is compared to the loaded same values, but what difference does it make at the end of the day?
Indeed, 'what are we missing?"
gar
Senior Member
- Location
- Ann Arbor, Michigan
- Occupation
- EE
141015-1940 EDT
I can not say for sure, but I think Tom wants information on the motor load to get information about the amount of product being moved. Without measuring ouput torque and speed (expensive) the use of input power can be effecftive and lower in cost. No load to full load current does not vary much for an AC induction motor.
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I can not say for sure, but I think Tom wants information on the motor load to get information about the amount of product being moved. Without measuring ouput torque and speed (expensive) the use of input power can be effecftive and lower in cost. No load to full load current does not vary much for an AC induction motor.
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ptonsparky
Tom
- Occupation
- EC - retired
It is not so much that you can't trust your amp meter for overloads, but stretch that information out 1000 times. Now you can start tracking a trend. The trend that sold me was when I spotted at what time of the day the bulk bin was running low on corn. Power to run a supposedly full mixing auger dropped 500 points IIRC. I would have to go back and check the data.
While I am using it to track wattage the Other Vendor was using it to relate directly to pounds per minute.
Loads that need some detail will get one from now on.
While I am using it to track wattage the Other Vendor was using it to relate directly to pounds per minute.
Loads that need some detail will get one from now on.
mike_kilroy
Senior Member
- Location
- United States
I figured that was where you guys were going with the discussion, rather than trying to say clamp on ammeter will not give you go/no-go data about if a motor is being overloaded or under utilized on a static none changing load, which it fully will of course. OK.
"Loads that need some detail will get one from now on."
So an idea for those future jobs: an alternative to paying the high price for that complex & expensive wattmeter gadget can be using a vector drive instead - it will separate out the torque producing current from the magnetizing and you get real load data on the motor that way too. Lots of drives today even will do the math for you and offer up real time HP (watts) load too....
"Loads that need some detail will get one from now on."
So an idea for those future jobs: an alternative to paying the high price for that complex & expensive wattmeter gadget can be using a vector drive instead - it will separate out the torque producing current from the magnetizing and you get real load data on the motor that way too. Lots of drives today even will do the math for you and offer up real time HP (watts) load too....
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