2-4 Malfunctions with Indications
Fault Setup Parameters
Certain Faults have setup parameters associated with them. They allow the
user to set thresholds and time delays according to the particular
application. A description of faults with setup parameters follows:
No. Name Description Associated Parameter(s)
VP-10 Feedback
Loss
This Soft fault occurs when the
measured velocity feedback from
the selected feedback device is less
than parameter 732 “Tach Loss Vel”
and the CEMF of the motor is
greater than parameter 731 “Tach
Loss CEMF”.
Velocity Fdbk (106) < Tach Loss Vel
(732), AND calculated CEMF from
Arm Voltage Fdbk (105) > Tach Loss
CEMF (731), THEN Fault on
Feedback Loss.
Parameter 731 “Tach Loss CEMF”. This
parameter indicates the lower limit of CEMF of
the motor voltage allowed for determination of
feedback loss. Programmable range is 0-33%.
Parameter 732 “Tach Loss VEL” This parameter
indicates the upper limit of velocity feedback
measured by the selected feedback device
allowed for determination of feedback loss.
Programmable range is 0.244, ±10%.
Parameter 731 “Tach Loss CEMF” must always
be programmed to a value greater than
parameter 732 “Tach Loss VEL” or nuisance trips
will occur.
VP-12 Absolute
Overspeed
This Soft fault occurs when motor
velocity exceeds the maximum
forward/reverse speed limits by the
absolute overspeed level.
Parameter 724 “ABS Overspeed” This
parameter indicates the incremental motor
velocity (RPM) above parameter 607 “Rev
Speed Limit” or parameter 608 “Fwd Speed
Limit” that must be detected in parameter 106
“Velocity Fdbk” to cause the above fault.
Programmable range is zero to Base Speed.
See also parameters 607 “Rev Speed Limit” and
608” Fwd Speed Limit”.
VP-13 Motor Field
Loss
This Soft fault occurs when the field
current feedback is less than 50% of
field current reference for the time
delay specified.
Parameter 730 “Fld Failure Dly” This parameter
indicates the time the field current feedback
must remain less than 50% of the field current
reference before the above fault is indicated.
Programmable range is 0-5 seconds.
Parameter 627 “Flux Mode Select”. Bit 6 can be
used to disable field loss detection. For normal
operation, set it to 0 to detect field loss
conditions.
VP-14 SCR
Overtemp
This fault occurs when the SCR heat
sink (HST) thermoswitch and/or
vane switch (MKVA) opens after the
specified time delay.
Parameter 726 “SCR Overtemp Dly”. This
parameter indicates the time the thermoswitch
must remain open before the above fault is
indicated. Programmable range: 0-3276.7 secs.
VP-15 External
Overtemp
This selectable fault occurs when
the external overtemp discrete input
(TB3-1& 2) is low for the time delay
specified.
Parameter 725 “Motor Ovtemp Dly”. This
parameter indicates the time the discrete input
must remain low before the above fault is
indicated. Programmable range: 0-3276.7 secs.
Verify that the motor thermostat is properly
wired. If the motor is not equipped with a
thermostat, 115 VAC or 24V DC must still be
applied to TB3 terminal 2. See 1395 Installation
Manual (publication 1395-5.40).
!
ATTENTION: Uncontrolled motor rotation can cause injury or equipment damage i
field loss detection is disabled. Field loss protection can only be disabled if using a
external field supply. Set bit 6 to disable field loss detection.
Aotewell Ltd industry-mall.net
To Next Page
Loading...
Need help?
General
