Yaskawa E7L Drive Bypass - Manual (Page 86)

Start Up and Operation 4 - 8
11. If the circuit breaker option is not present - go to step 12.
In preparation for testing the Bypass, observe the trip setting of the Circuit Breaker. The trip point is factory set at the
lowest possible setting and must be adjusted for each application. This breaker will trip due to inrush current and load
inertia unless it is reset!
•
For fan applications adjust the trip setting to ten times motor FLA.
• For pump applications adjust the trip setting to six times motor FLA.
If Circuit Breaker tripping is experienced at these settings during motor starting on Bypass, increase the setting
gradually until the motor can be started without Circuit Breaker tripping.
12. Press the OFF key and press the BYPASS Select key. The Drive will ramp the motor to zero speed, then the control
will be transferred to Bypass mode. Be prepared to monitor the rotation direction of the motor in Bypass operation.
“Bump” the HAND key and quickly press the OFF key. Check the motor rotation. Do not allow the motor to continue
operating in Bypass mode until rotation is correct!
If the rotation direction in Bypass is correct, skip the rest of this step. If not, carry out the following corrections:
1. Turn OFF the incoming power feed to the E7L unit. Since the correct rotation in Drive mode was previously
established, do not change any output wires at the motor.
2. Instead, verify that power is OFF. Then swap the wires for L1 & L2 on the input side of the Disconnect Switch or
Circuit Breaker. This will effect rotation in Bypass operation only. Once connections are complete and tight,
reapply the incoming power and repeat the previous step to re-check the rotation direction in Bypass mode.
13. Run the motor in Bypass by pressing the HAND key. Record all the phase voltages and currents at this time.
14. Press the OFF key and press the DRIVE Select key. Press the HAND key and press the DATA/ENTER key, then
scroll the Speed Command to “60 HZ” operation. Monitor the voltages and currents in each of the output phases at full
speed to make sure that the voltages are balanced and that the currents are within the motor nameplate rating during
accel, stable speed, and decel.
15. If this application requires the Drive to operate in PI mode, see Chapter 5.
For serial communication, refer to Appendix D in this manual or TM.E7.21 (APOGEE FLN) and TM.E7.22 (Metasys N2).