Lenze i700 - Manual (Page 256)

8 Monitoring functions
8.7 Motor phase failure monitoring
256
Lenze · i700 servo inverter · Reference manual · DMS 1.5 EN · 03/2014 · TD05
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
8.7.2 Monitoring 2: In the "enable operation" state transition
On the basis of test signals, this extended monitoring function for motor phase failure can detect a
phase failure and check the presence of the motor. Only after a successful check, the actual
operation is continued.
• Monitoring is only active for a short time after controller enable (when the device status
changes from " Switched on " to " Operation enabled ") if
• a response other than "0: No response" has been set for this monitoring function in object
0x2D45:4 (or 0x3545:4 for axis B), and
• no test mode and no identification mode ( 0x2825 or 0x3025 for axis B) are active.
• Before the actual operation, the motor is supplied with a maximum DC current, the max. level
of which can correspond to the lower of the following two values:
• The response set is triggered if one or several motor phase currents have not reached a specific
threshold value within 5 ms after controller enable. The threshold value depends on the
maximum device current and cannot be parameterised.
• The check is completed successfully if all three motor phase currents have exceeded the
threshold value. Then the actual operation is continued immediately.
8.7.3 Monitoring 1: In "operation enabled" status
If a current-carrying motor phase (U, V, W) fails during operation, the response set for this
monitoring is tripped if two conditions are met:
• Condition 1: Monitoring is activated
• In order to be able to reliably detect the failure of a motor phase, a certain motor current for
the current sensors must flow first. The monitoring function therefore is only activated if, in
the case of a servo control, the setpoint of the motor current, and in the case of a V/f
characteristic control, the actual value of the motor current (display in 0x6078 or 0x6878 for
axis B) has exceeded a parameterisable current threshold.
• Condition 2: A specific commutation angle has been covered without the detection of a current
flow.
• In this case monitoring works according to the principle of checking for each motor phase
that a current flows depending on the commutation angle.
• Monitoring responds if a rotating field is output and hence a specific commutation angle
(approx. 150°, electric) is covered without the current having exceeded a (non-
parameterisable) threshold that depends on the device power.
or

Note!
• As the check is cancelled immediately if all three motor phase currents have exceeded
the threshold value, the setpoint current usually is not achieved.
• In order to be able to achieve the threshold value used for the check, the rated motor
current must at least be 10 % of the maximum device current.
• This monitoring is independent of the further rotation of the commutation angle.
50 % 2 Rated device current ⋅ ⋅
50 % 2 Rated motor current ⋅ ⋅