Hitachi WJ200-001S Instruction Manual page 529

Ver.3− − − − 20
W hen b910 = 02
②
When output current is less than thermal count level, subtracted constantly with fixed rate as max
value thermal counter (trip level) down to 0 within the time defined with thermal subtraction time
(b911).
Output Current
Thermal Count
Thermal Counter
w hen b910 = 03
③
When output current is less than thermal count level, subtracted with the value equal to thermal
counter value multiplied with linear filter of time constant (b912) and target as 0. (when output
current keeps to be less than thermal count level, thermal counter becomes 0 within a time
approximately 5 times b912)
Output Current
Thermal Count
Thermal Counter
Level
Thermal Counter
100[%]
(trip level
Fig.2 Thermal Counter Subtraction Image when b910=02
Level
Thermal Counter
100[%]
Trip level
Fig3. Thermal Counter Subtraction Image when b910=03
Output Current
100%/b911
b911
Output Current
Subtraction rate
Calc. b912
b912
5 times of b912
Trip
Trip