GE Industrial Solutions ASTAT BP User Manual
Page 69
ASTAT BP User Manual
69
GE Industrial Solutions
©2013 GE Company All Rights Reserved
88..77
Inside Delta Configuration
8.7.1
General Information
When the ASTAT-BP is installed Inside Delta, the individual phases of the ASTAT-BP are connected in series with
the individual motor windings (6 conductor connections as with the star-delta starter). The ASTAT-BP must only
conduct about 58 % (=1\
÷3) of the rated motor current. This allows the use of a significantly smaller ASTAT-BP.
Note that although when connected Inside Delta the current is reduced by 1.73 (√3), you should choose an
ASTAT-BP as if current is reduced only by 1.5. (1/1.5=0.667=67%)
For example:
For a motor with a rated current of 870A motor, a 960A starter will be selected to operate In-Line.
For Inside Delta ASTAT-BP, we calculate (870 x 67% = 580A) and select a 590A starter.
8.7.2
Notes on Inside Delta Connection
Inside Delta requires 6-wires to the motor.
Wrong motor connection might cause serious damage to the motor windings.
When installing the ASTAT-BP Inside Delta it is highly recommended to use a contactor in series to the ASTAT-
BP or upstream (after motor protection) in order to avoid a damage to the motor if the ASTAT-BP short circuits.
The sinusoidal shape of the current might be imperfect. As a result, higher harmonic content is incurred (THD),
which may be twice the THD value as in the standard In-Line connection.
Motor heat may increase (due to the higher THD).
Phase sequence to the input of the ASTAT-BP (1L1, 3L2 & 5L3 terminals) must be correct. Otherwise,
Phase
Sequence fault will trip the ASTAT-BP immediately.
Higher torque can not be obtained.
The following factory preset features and functions are not active when Inside Delta mode is configured:
Kickstart
Soft Start Curve selection (Soft Start Curve 0 !! only).
Slow Speed TRQ. (slow speed)
Phase Sequence in OFF mode
Note :
For a high starting torque process, it is recommended to use the ASTAT-BP in the In Line connection.