Basler Electric SMC-250 - Manual (Page 5)

Details about the BE3-74SD are provided in Basler
publication 9320800990.
STARTUP AND SHUTDOWN
SMC-250 startup and shutdown sequences are
described as follows.
Startup
SMC-250 startup should coincide with the application
of a motor start command. Upon SMC-250 startup,
the DECS-250 begins regulating excitation in Field
Current Regulation (FCR) mode.
Startup is initiated through application of a contact
input at terminals TB1-21 and 22 which energizes
Start/Stop Relay K1 and contact IN1 of the BE1-11m.
(Startup cannot occur if the user-supplied lockout
(86) device is tripped.)
When energized, K1 applies operating power from
the external PPT to the ICRM and DECS-250 and
applies a Start contact input to the DECS-250. This
enables field current regulation by the DECS-250.
When IN1 of the BE1-11m is energized, it enables the
BE1-11m to close output contact OUT4 when it
senses nominal ac motor current. Closure of OUT4
applies a contact input to DECS-250 IN6. This places
the DECS-250 in Auto mode and enables regulation
of motor power factor. The energizing of BE1-11m
IN1 also initiates an internal BE1-11m time delay
which, during timing, prevents trips related to motor
startup from the BE3-74SD, DECS-250, and
BE1-11m. once the time delay expires, BE1-11m
OUT5 closes and enables the BE3-74SD
underexcitation and overexcitation output contacts,
DECS-250 underexcitation (backup) and
overexcitation (backup) output contacts, and BE1-
11m major fault output contacts to close the SMC-250
Alarm output if conditions dictate.
Shutdown
SMC-250 shutdown is initiated through removal of
the Start contact applied at terminal TB1-21 and 22
or a trip of the user-supplied lockout (86) device.
Initiation of an SMC-250 shutdown de-energizes K1
and IN1 of the BE1-11m.
When de-energized, K1 disconnects the ICRM and
DECS-250 from the output of the PPT and applies a
Stop contact input to the DECS-250. This disables
regulation of excitation by the DECS-250.
De-energizing BE1-11m IN1 opens BE1-11m outputs
OUT4 and OUT5. OUT4 switches the DECS-250
from Auto mode to FCR (Field Current Regulation)
mode. OUT5 prevents the BE3-74SD, DECS-250,
and BE1-11m from closing the SMC-250 Alarm
output.
SPARE/RESTORATION COMPONENTS
A reasonable stock of spare parts will minimize
downtime in the event of an equipment malfunction.
A list of recommended spare parts accompanies this
publication.
Publication
9494900994
Revision
A
Instructions
Date
10/14
Page
5 of 6