Toshiba VF-SX - Manual (Page 109)

U-2
TOSHIBA
This portion of the manual describes the different types of protective
parameters, functions, and settings available on the Toshiba VF-SX drive. These
parameters are listed below.
1. [ P b ] Regenerative Discharge Braking Resistor
2.
[OPSS]
Overvoltage Limiting Action Selection
3.
[ d b F
] DC Injection Braking Start-up Frequency
4. [ d b U ] DC Injection Braking Voltage
5. [ d b b ] DC Injection Braking Time
6
. [ f 5 t P ]
Emergency Stop
7. [ E d b b ] Emergency DC Injection Braking Stop Control Time
8. [r’tr’y] Retry Selection
9. [ U u C ] Power Control Function Selection
10. [tHr] Electronic Thermal Protective Level
11.
[ 5 b i
]
stall
Prevention Function Activation Level
12. [ O L H ] Electronic Thermal Protection Characteristic Selection
13. [
t
^
C L
] Trip Retention Selection
11.1 Regenerative Discharge Braking Selection
[Pb]
and
Overvoltage Limiting Action Selection
[OPSS]
The regenerative discharge brake can be selected to prevent overvoltage trips
which occur due to rapid deceleration or rapid deceleration to stop.
Use the standard braking resistor for the following conditions:
1. SX drive is rated 1/2 HP — 5 HP
2. Regenerative braking time is 5 seconds or less (during each stop).
3. Usage rate (duty cycle) is 3* of running time, or less.
See Chapter 15 for the standard ratings of discharge resistors.
The resistor can become very hot during high cycle operations, or when long
deceleration times keep a large load on the resistor. Take care when installing
the external resistor. Do NOT mount it on a combustible base material. In
general, keep it away from any combustible material, and provide adequate room
for air flow to help cool the device.