Table of Contents
Advertisement
MCO351 Positioning Controller
6. Troubleshooting
6.1. Frequently Asked questions
Q1:
When I have a "PID TRACK ERROR TOO BIG" error (par. 798="9"), the inverter also trips on
ALARM 13 (OVER CURRENT).
A1:
a) Check that the velocity setting (par. 723 for jogging and par. 738/par. 742 for positioning) is
at least 5% lower than the maximum allowed velocity calculated in par. 799. Either lower the
velocity (par. 723 or par. 742) setting or raise the maximum allowed velocity (par. 799) by setting
a higher value of par. 205 - please see Q2.
b) The quick stop ramp time (par. 719) could be too short. Try to increase the setting.
Q2:
How do I adjust the maximum allowed velocityin par. 32-80?
A2:
You need to raise the setting of par. 303. Doing this will also affect the performance of the pa-
rameters par. 32-60 to 32-66. Smaller changes to par. 303 may not have any noticeable effect on
most of these parameters but par. 32-65 should always be recalculated using the auto-calculation
function par. 19-19.
Q3:
The inverter frequently trips on ALARM 7 (DC LINK OVERVOLTAGE) while ramping down.
A3:
a) Use a higher ramp time setting (par. 719 for "quick stop", par. 724 for jogging and par. 738/
par. 741 for positioning).
b) If a lower ramp time is required a brake resistor should be installed.
Q4:
The inverter frequently trips on ALARM 13 (OVER CURRENT) while ramping up
A4:
a) The ramp settings may require too much torque. Try to determine which operation ("quick
stop", manual move or positioning) caused the trip, and then set the corresponding ramp time
(par. 719 for "quick stop", par. 724 for jogging and par 738/par. 741 for positioning) with a higher
ramp time setting.
b) The PID controller settings may be unstable – re-optimise the PID controller parameters (par.
702-709).
MG.33.R1.02 - VLT
®
is a registered Danfoss trademark
6. Troubleshooting
6
41
Advertisement
Table of Contents
