Yaskawa VCD 723 - Manual (Page 34)

2 Installation and Start-up
28 Drive Start-up
9/15/93
●
As part of the program’s start-up procedure, the validity of the nonvolatile
parameters are checked. If the values are invalid, the following message is
displayed on the Local Control display Unit:
BAD NVRAM CRC
ENT FOR DEFAULTS
If this occurs, press the ENT key. The factory programmed default values
will then be loaded into non-volatile memory.
❏ The parameter values should be checked for proper settings. The settings
will be shown on the Function list supplied with the order documentation.
Refer to Section 3 to find the operating procedure necessary to view and
change parameter values. These parameter values include the following:
●
Speed Reference Setting Constants (i.e., Main Speed Reference, Jog
Speed Reference).
● Application Constants (i.e., Accel Time, Decel Time, Forward Side
Torque Limit).
●
Control Constants (i.e., Speed Reference Input Limit, Pulse Generator
Pulses Per Motor Revolution, Motor Overload Detection starting Current).
● Motor Constants (i.e., Base Speed, Number of Motor Poles, Motor Rated
Current, Rated Slip Frequency).
●
Order Constants (i.e., Select Control with or without Pulse Generator
Feedback, Select Control with or without motor thermistor).
●
System Constants (i.e., MagneTek Vector Control Motor Selection,
Input/Output Function Assignments, Control Behavior Selections, Carrier
Frequency Selection).
● Any other values that may be job specific (i.e., Empty Roll Diameter for
winder applications, Follower Pulse Generator Pulses Per Revolution).
❏ Check the Pulse Generator’s (PG) rotation.
●
Select the parameter to view the PG Feedback (function number 604).
●
Manually rotate the shaft counter clockwise, as viewed from the shaft end.
Verify that the displayed PG feedback is positive.
If the display does not change from “0”, check the PG cable connections.
If the problem persists, check for pulses at test points “PA” and “PB” on
the right-hand side of the PG-X card, with an oscilloscope.
If the PG feedback shows a negative sign (“-”), reverse the polarity by
reversing the wiring between the A and B channels. This is accomplished
by switching the wire labeled A+ with wire labeled B+, then switching
wire labeled A- with wire labeled B-.