Ecb Auto Bypass - Danfoss VLT Option Panel Instruction Manual

ECB Auto Bypass

General Information
Auto bypass allows a fault condition in the drive
to activate running the motor in bypass without
operator intervention. Activation of the function
is through setting timer start parameters in the
drive programming. Fault trip and running in
bypass are reported through the drive display,
digital outputs, and serial communications. In
addition, the independently powered ECB card
is available to report bypass status when the
drive is inoperable (control card operative)
through its serial communications or digital
outputs.
Prior to Enabling Auto Bypass
•
Complete the start-up procedure to
verify motor rotation direction in bypass
is correct and that the system is ready
in all respects for continuous full speed
operation in bypass.
Operation
•
With the auto bypass function enabled,
a fault signal from the drive activates the
auto bypass timer.
•
If the fault clears before the time delay is
complete, the motor remains operating
in drive mode. This allows temporary
faults, such as a momentary under or
over voltage, to clear without transferring
the system to bypass.
•
If the timer completes its cycle before
the fault clears, the panel trips into
bypass mode and the motor runs at
constant full speed from line input
voltage.
•
In bypass, the motor will stop:
if the drive receives a remote
-
stop command
local stop (OFF key) on the
-
drive keypad is pressed
a remote start command is
-
removed
a safety is open
-
motor overload is tripped
-
44
•
Once auto bypass is activated, the only
way to reset the unit back to drive mode
is by operator intervention. Ensure that
the fault has been cleared, then press
the BYPASS key on the drive keypad
and select drive mode.
Auto Bypass Function Setup
Enable auto bypass by changing parameters in
group 31 in the drive extended menu.
•
31-01, Bypass start time delay. Setting
the timer at anything other than 0 time
activates start delay in bypass. Leave at
30 second default or set as desired up
to 60 seconds.
•
31-02, Bypass trip time delay. Setting
the timer at anything other than 0 time
activates auto bypass. Leave at 5
second default or set as desired up to
60 seconds.
Parameter 31-02 Bypass Trip Time Delay
Drive Display with Bypass Start Time Delay
Active