GE Industrial Solutions 6KBU300 Braking Unit - Manual (Page 25)

6KBU300
—————— MINIMUM VALUE OF OF THE RESISTANCES ——————
5 1
5. MINIMUM VALUE OF THE RESISTORS THAT CAN BE USED
Model Value of intervention threshold
400V 640V 680V 745V
Minimum value of resistors
6KBU300-20 10 ohm 16 ohm 17 ohm 18.6 ohm
6KBU300-50 4 ohm 6.4 ohm 6.8 ohm 7.5 ohm
6KBU300-85 2.4 ohm 3.7 ohm 4 ohm 4.4 ohm
bu0040
The ohmic value indicated in the table, represents the absolute minimum value of the resistor connectable to
the different braking units in correspondence of the braking threshold set.
In case these values would not be available, it might be possible to use higher ohmic values.
E.g. with the braking unit 6KBU300-20 used with intervention threshold of 680V the indicated resistor value is
17
Ω
, if the commercial available ohmic value is 18
Ω
, it will be allowed its use with no problem (don’t use
16
Ω
).
The indication is for a best use of braking resistors when more parallelled resistors are used, case in which the
ohmic values indicated in the table should not be available.
A
TTENTION
!!
Units are not protected against direct short-circuit between terminals CR, BR. This
condition can lead to the destruction of the unit, if external DC fusing is not supplied.