Toshiba VF-SX - Manual (Page 110)

TOSHIBA
11-3
If a fault occurs due to an abnormally high power voltage or element error in the
inverter and a current flows constantly to the resistor, the thermal fuse in the
braking resistor circuit will blow. In this case it is not uncoiimion for a small
amount of smoke to arise from the resistor, and the resistor surface temperature
may be extremely high. Do not install the resistor directly onto any flammable
surface or subpanel.
CAUTION:
When using a braking resistor other than the standard unit, install an
input contactor or a main circuit breaker with a shunt trip on the inverter
incoming power. Electrically interlock this device so that the power
circuit will open with the operation of the fault relay (FL) in the
inverter or an external overload relay.
TABLE 11-1: SETTINB OF THE REGENERATIVE DISCHARGE RESISTOR PROTECTION PARANETER
[ P b ]
Value
Function
0
Regenerative Discharge Braking not engaged.
/
Regenerative Discharge Brake engaged, no braking resistor
overload detection (when an VERY large resistor is used).
г
Regenerative discharge brake engaged, braking resistor
overload detection is ON (when the standard size resistor
is used).
The overvoltage stall operation refers a voltage increase on the DC bus during
deceleration. This DC voltage rise can be automatically limited to prevent
tripping on overvoltage. Thus, the deceleration time may be longer than the set
deceleration time.
TABLE 11-2: SETTING OF THE OVERVOLTAGE STALL PARAMETER
(OP 5 5]
Value
Function
0
Overvoltage stall operates. (This setting
is ignored
if [ P b ]
is / or
P.)
/
No overvoltage stall operation.