GE Industrial Solutions ASTAT XT - Manual (Page 38)

38 • Control Keypad
4.7.7
Fault Settings 39 – Page 6
Function &
Default
Range Unit Description
Phase Loss
Enabled
Enabled 40 Sets Phase Loss trip
Phase Loss protection trips the ASTAT-XT when 1 or 2 phases
are missing.
Notes:
If ASTAT-XT trips on Phase Loss do the following:
(1) In cases where the current transformers are connected
externally (ASTAT-XT 950-1400A models), verify that that
the current transformers are not grounded. Each current
transformer is connected with its 2 wires only and these
wires are not grounded externally.
(2) Check phase voltages related to terminal 21 even if
terminal 21 is not connected. Verify that phase voltages
are within the required range of line to neutral voltages.
(3) Verify that terminal 21 is connected correctly. For terminal
21 connection refer to section 8.1 on page 62.
(4) If terminal 21 is connected correctly, disconnect terminal
21 and try to start when terminal 21 is disconnected.
(5) If all previous actions are do not solve the problem and
the you are sure that no real phase loss exists, you can set
Phase Loss protection to Disable.
This situation can occur in rare cases when there is no real
fault but the ASTAT-XT recognizes unusual behaviour like
when Total Harmonic Distortion in Voltage (THDV) in the
network is high.
(6) If this is a true case of Phase Loss then after setting
Phase Loss
protection to Disable the motor will
single phase and most likely be tripped by the over load
protection mechanism.
(7) Phase loss might not be detected in motor operating
under a light load.
WARNING
Do not set Phase Loss to Disable unless it is found to be
necessary in the field!
Phase Sequence
Disabled Enabled/
Disabled Sets Phase Sequence trip
When ASTAT-XT is connected in DELTA Conf. you can not
set Phase Sequence protection to Disabled.
Auto Reset
Disabled
Enabled/
Disabled Sets ASTAT-XT’s Auto Reset mode of operation.
The ASTAT-XT can be automatically reset for Undervoltage
and Phase Loss faults.
Refer to section
4.7.2 on page 27 for details on setting
Undervoltage
protection.
To start the motor after Undervoltage and Phase Loss
faults have been cleared, remove the START signal and
recommence the signal.
Auto Reset function has a non-programmable time delay of 60
seconds.
Note:
The Auto Reset operation is limited to 10 operations.
39 Displays in MINIMIZED MODE and MAXIMIZED MODE.
40 The range of the PHASE LOSS can be extended to Enabled or Disabled by using the EXPANDED SETTING as described in
section 5.5.5 page 50.