CST

Units:

Rated Current: A_pk	Rated Torque: Nm	Torque Const. (K_t): Nm/A_pk	Bus Voltage: V	95% PWM: V
Peak Current: A_pk	Peak Torque: Nm	Back EMF Const. (K_e): V/rad/s	Phase->Phase Resistance: Ω

CST User Guide

1. What is your motor’s rated current? Check the ratings label on the motor or in the specification sheet and note A for Arms or Apk. Select proper units in CST and enter the correct value of motor rated current. Note: The units can be changed on the fly and CST will calculate values to match.

2. What is your motor’s rated torque? Check the ratings label on the motor or in the specification sheet and note Nm or oz-in. Select proper units—metric or English—in CST and enter the correct value of motor rated torque. Note: The units can be changed on the fly and CST will calculate values to match.

3. What is your dc bus voltage? If using Xenus, AC-powered drive, multiply the AC power by the square root of 2. Then take 80% of no-load dc to get the minimum dc bus voltage. For example, 240V AC * 1.414 = 339 Vdc (no-load). 339 Vdc * 0.8 = 271 Vdc (minimum).

4. What is your motor’s winding resistance? Check the ratings label on the motor or in the specification sheet and note Ohms phase-to-phase. If given as phase-to-neutral, multiply the resistance by 2 to get Ohms phase-to-phase. Use an Ohms-meter to measure the resistance between pairs of wires or all pairs of wires. Make sure the power is off when measuring resistance. Enter the correct value of motor resistance.

5. Press the “Calculate” button to generate a speed-torque curve. Verify that the required speed and torque of the application is satisfied. For example, if we would like to go 3000 RPM in our application, can we do that at the rated current and at twice the rated current for typical peak?

6. Some motors are capable of delivering 3 times the rated torque at peak for some period of time. If we would like to see the effects on the speed-torque curve at higher torque or current levels, press the “Unlock” button and enter the higher current value. After entering the new values, press the “Calculate” button again to see the effects on the speed-torque curve. This will affect the top speed and may affect the required speed.

7. Take a screenshot of the speed-torque curve and save the assumptions to a file named after the motor we are using.

8. Select a Copley drive that provides the voltage and current required in the application.

*Any time the “Calculate” button needs to be pressed, the same effect can be achieved by pressing the “Enter” key on the keyboard.