29
EMB 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 DIP switches
(S103) located on the EMB2 bypass control
card (see Figure 5-2). A fault condition en-
ables a delay timer prior to tripping the drive
into bypass. The fault trip and running in
bypass are reported as output from the
bypass control card. The auto bypass func-
tion is built-in.
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.
H
IGH
V
OLTAGE
!
R
EMOVE POWER TO BYPASS PANEL BEFORE SETTING AUTO BYPASS
DIP
SWITCH SETTINGS
. B
YPASS CAN CONTAIN HIGH VOLTAGE
.
F
AILURE TO REMOVE POWER TO BYPASS PANEL BEFORE SETTING
DIP
SWITCHES COULD CAUSE PERSONAL INJURY OR DEATH
.
Operation
•
With the bypass selector switch in
drive and auto bypass enabled, a fault
signal from the drive will activate the
auto bypass timer.
•
If the fault clears before the time delay
is complete, the motor remains oper-
ating in drive mode. This allows
temporary faults, such as a momen-
tary 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 safety
or motor overload conditions are
exceeded.
•
Once auto bypass is activated, the
only way to reset the unit back to drive
is by operator intervention. Ensure that
the fault has been cleared, then rotate
the bypass switch to the OFF position
momentarily before setting it back to
the drive position. This resets the
drive and fault timer.
Auto Bypass Function Setup
Enable auto bypass by closing one or more
DIP switches on switch S103 located on the
bypass control card. (Times are approxi-
mate.)
•
All OFF = no auto bypass operation
•
1-3 ON = 15 second delay (minimum)
•
Switch 1 only ON = 30 sec. delay
•
Switch 2 only ON = 60 sec. delay
•
Switch 3 only ON = 300 sec. delay
(maximum)
•
Switch 4 = Always OFF
WARNING
!
