CERUS CI-007-P2, Installation, Programming Operation, & Maintenance Manual

Page: 75 / 137

Chapter 6 - Parameter Description
6-8
SET LDT trip
80 Yes SET LDT FillTime
81 60.0 min
If SET-66 and SET-67 are set to 0.0%, VFD
starts and stops AUX motors only based on
start/stop Frequencies and Delays and does not
monitor feedback signal.
)3/+ ! " " & " & !
The SET-74 parameter
has three selections:
• No -the level detection function and related
parameters are disabled.
• Under Level - VFD monitors a selected Level
Detection Source for Under Level condition.
• Over Level - VFD monitors a selected Level
Detection Source for Over Level condition.
)37+ & ! '" !
The SET-75 parameter
provides six LDT
source selections: Current, DC Voltage, Output
Voltage, kW, V1 and I.
• Current -the LDT function monitors motor
current
• DC Voltage - the LDT function monitors DC bus
voltage
• Output Voltage - the LDT function monitors
VFD output voltage
• kW - the LDT function monitors VFD operating
kW
•
V1
- the LDT function monitors 0-10VDC
analog input signal
• I - the LDT function monitors 4-20mA analog
input signal.
•
)30+ " 2' !
The LDT function starts
monitoring the level of
selected source when VFD speed increases above
SET-76 setting.
)33+
The LDT function will
activate LDT relay or
trip VFD when monitored level meets trigger
conditions for SET-77 delay time.
)34+ &
The SET-78 LDT Level
parameter sets the
trigger point for LDT function. If SET-74 is set to
Under Level, the LDT function will be triggered at
level below SET-78. If SET-74 is set to Over Level,
the LDT function will be triggered at level above
SET-78.
)35+ # "
The SET-79 LDT Level
parameter sets a
hysteresis for resetting the triggered LDT function.
If LDT trips on Under Level, the LDT function will
be reset at level above [SET-78]+[SET-79]. If LDT
trips on Over Level, the LDT function will be reset
at level below [SET-78]-[SET-79].
)4*6 4 + " !
< " " !=
When SET-80 LDT VFD Trip is set to YES the
SET-81 LDT Fill Time parameter is enabled. The
VFD will trip at LDT Level and try to restart after
SET-81 time delay. This feature is intended for Dry
Well protection and SET-81 should be adjusted
properly to provide enough time for the well to be
filled. If well is still dry the VFD will continuously
cycle restart attempts every time the SET-81 delay
time expires. If SET-81 is set to 0.0min, VFD will
not restart automatically after UnderLevel fault.
)4 + ' '
The selected relay
output AUX-3 or AUX-
4 will be activated when LDT function is triggered
and deactivated when LDT is reset at hysteresis
level.
Example: If SET-74 is set to Under Level, SET-75
to Current, SET-76 to 59.0Hz, SET-78 to 9.0A and
SET-79 to 1A, the LDT function will activate LDT
relay when VFD runs at speed higher than 59Hz
with current less than 9A and deactivate when
current increases above 10A.
SET Level Detect
74 Under Level
SET LDT Source
75 Current
SET LDT Freq
76 59.00 Hz
SET LDT Delay
77 2 sec
SET LDT Level
78 9.0 A
SET LDT Hyst
79 1.0 A
SET LDT Relay
82 AUX_3