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5.1.4 EMB2 Run Permissive
General Information
Run permissive allows a remote signal to notify the drive
to start, indicating the system is safe to operate. Run
permissive works in drive or bypass mode. Run permissive
is enabled by factory default and can be disabled by
switching dip switch #4 on S105 to the on position or
placing a jumper wire between terminal 1 and 2 of the
X55 customer connector.
Prior to Enabling Run Permissive
•
Complete the start-up procedure to verify that
motor rotation direction in bypass is correct and
that the system is ready in all respects for
continuous full speed operation in bypass.
•
Verify that the drive is programmed for the run
permissive function. See the drive support
manual provided for information on
programming the run permissive function.
Operation
•
A start command can be from local hand start on
the drive keypad or a remote auto start signal
through digital input connector X55 terminals 3
and 4, or via the serial communications input.
•
In response to a start command, an output
request is sent from X55 terminals 11 and 12 to
the external equipment (to activate a valve or
damper, for example).
•
When a return run signal on X55 terminals 1 and
2 is received, the motor is started in either drive
or bypass mode, depending upon the bypass
switch position.
Run Permissive Function Setup
•
Remove the factory-installed jumper wire on
connector X55, terminals 1 and 2.
•
Wire the output run request to connector X55,
terminals 11 and 12.
•
Wire the input run permission to connector X55,
terminals 1 and 2 per the system application.
Disable Run Permissive
•
Run permissive is enabled by factory default
when ordered.
•
To disable the run permissive function, jumper
between terminals 1 and 2 on connector X55 or
use dip switch 4 on 5105.
5.1.5 EMB2 Overload
General Information
The overload device provides overcurrent protection for
the motor when running in bypass. The thermally activated
overload monitors motor current and trips to remove
power to the motor if a sustained over-current condition
exists. A Class 20 overload is standard with a variable
setting for motor current. Test and reset buttons are also
provided. In drive mode, the drive provides current sensing
and trip protection. Fuses provide quick action for high
over current conditions.
Prior to Enabling Overload
•
Verify that the overload current dial setting
matches the motor FLA rating on the motor
nameplate.
•
If the motor FLA is greater or less than the range
of the current dial, reconfirm that the motor hp
and voltage are within the option panel (and
drive) rating. If greater than the FLA rating,
replace the panel with one of a proper rating.
CAUTION
MOTOR DAMAGE!
Repeated attempts to reset an overload can cause motor
damage. Correct the overload condition and let the
overload and motor return to normal operating
temperature before resetting. See motor manufacturer’s
recommendations for time between start attempts. Failure
to correct the overload condition and let the motor return
to normal operating temperature could cause motor
damage.
Operation
Overloads are rated by class. The class is defined by the
NEC to determine the maximum time to trip. A Class 20
overload, for example, has a typical trip delay of 20 sec. or
less at 600% current and normal operating temperature.
This allows for high motor inrush current for 20 sec. while
the motor is ramping up to synchronous speed. The trip
time, however, is based on the percentage of overload.
The higher the overload, the shorter the trip time. It is
important that the overload class not exceed the motor
class rating or motor damage could occur.
Overload Function Setup
•
Set the overload current dial to the FLA of the
motor. DO NOT add the service factor of the
motor into the setting. A service factor of 120%
for Class 20 is designed into the overload.
•
Pressing the test pushbutton verifies the
operation of the overload. The overload should
Electromechanical Bypass (E...
5-4 BAS-SVX49A-EN