Yaskawa E7B Drive Bypass System - Manual (Page 47)

Yaskawa Electric America, Inc.
Installation Guide IG.E7B.02 Rev: 04-11
Date: 11-1-04 Page 45 of 46
11. 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 set-
ting 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 correc-
tions:
1. Turn OFF the incoming power feed to the E7B 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 out-
put 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 of TM.E7B.01.
For serial communication, refer to Appendix D in TM.E7B.01 or TM.E7.21 (APOGEE FLN) and TM.E7.22
(Metasys N2).