STS1072R vs STS1072RV1; capacitor hump; "Conservationist" mo

[mas985]

Re: STS1072R vs STS1072RV1; capacitor hump; "Conservationist

A.O. Smith, now called Regal Beloit, now has a two speed motor with a run capacitor for both the high and low speeds. They call it the E-Plus Centurion.

what i find strange from the spec pic is that watts are dropping as speed increases. i'm probably reading it wrong.

You have to be careful how you read torque curves. The x-axis is the speed of the motor but with the main full speed windings (note the chart is labeled high speed). In other words, it is reflective of slip. When a motor first starts the slip is 100% so RPM is 0. As the motor spins up, slip reduces until the motor settles at around 4% slip for full load. The chart can also be used for overloaded situtations where slip increases and power usage increases. So full load is on the right most side of the curve (3450 RPM) and overload moves the operating point to the left which slows down the motor, increases torque and increases power.

 

[Diver]

Re: STS1072R vs STS1072RV1; capacitor hump; "Conservationist

A.O. Smith, now called Regal Beloit, now has a two speed motor with a run capacitor for both the high and low speeds. They call it the E-Plus Centurion.

d*mn it!

what i find strange from the spec pic is that watts are dropping as speed increases. i'm probably reading it wrong.

You have to be careful how you read torque curves. The x-axis is the speed of the motor but with the main full speed windings (note the chart is labeled high speed). In other words, it is reflective of slip. When a motor first starts the slip is 100% so RPM is 0. As the motor spins up, slip reduces until the motor settles at around 4% slip for full load. The chart can also be used for overloaded situtations where slip increases and power usage increases. So full load is on the right most side of the curve (3450 RPM) and overload moves the operating point to the left which slows down the motor, increases torque and increases power.

makes sense. i was looking at it for the range of RPMs not realizing it was for single high speed

 

[Diver]

Re: STS1072R vs STS1072RV1; capacitor hump; "Conservationist

A.O. Smith, now called Regal Beloit, now has a two speed motor with a run capacitor for both the high and low speeds. They call it the E-Plus Centurion.

it looks like it's only available with 56Y frame, at least i can't find 56J that i would need. 1 amp max on low speed is nice. for STS1072RV1 low/high MAX amps are at 1:2.5 ration (2.2:5.4) which almost negates the idea of running on low for twice as long. i hope that running amps ratio is more favorable than 1:2.5

edit: it also looks like the new motor is almost twice more expensive..

 

[mas985]

Re: STS1072R vs STS1072RV1; capacitor hump; "Conservationist

You right, so far it only comes in a 56Y. The motor is about 20% more efficient on low speed than a standard two speed.