Hitachi SJ300 Series Manual De Usuario

Descargar
Página de 294
SJ300 Inverter
Oper
ati
ons
and Monitor
ing
4–45
Frequency arrival output [FA1] uses the 
standard output frequency (parameter F001) 
as the threshold for switching. In the figure 
to the right, the inverter accelerates to the 
set output frequency, which serves as the 
threshold for [FA1]. Parameters F
on
 and F
off
 
illustrate the hysteresis that prevents output 
chatter near the threshold value.
• F
on
 is 1% of the max. output frequency
• F
off
 is 2% of the max. output frequency
The hysteresis effect causes the output to 
turn ON slightly early as the speed 
approaches the threshold. Then the turn-
OFF point is slightly delayed. The 1% and 
2% values also apply to the remaining 
Frequency arrival outputs, discussed below.
Frequency Arrival outputs [FA2] and 
[FA4] work the same way; they just use 
two separate threshold pairs as shown in 
the figure. These provide for separate 
acceleration and deceleration thresholds 
to provide more flexibility than for 
[FA1]. [FA2] uses C042 and C045 for 
ON and OFF thresholds, respectively. 
[FA4] uses C043 and C046 for ON and 
OFF thresholds, respectively. Having 
different accel and decel thresholds 
provides an asymmetrical output 
function. However, you can use equal 
ON and OFF thresholds, if desired.
Frequency Arrival outputs [FA3] and [FA5] use the same threshold parameters as [FA2] and 
[FA4] above, but operate in a slightly different way. Refer to the diagram below. After the 
frequency arrives at the first threshold during acceleration and turns ON [FA3] or [FA5], they 
turn OFF again as the output frequency accelerates further. The second thresholds work 
similarly during deceleration. In this way, we have separate ON/OFF pulses for acceleration 
and deceleration.
FA1
Output
frequency
F001
ON
t
Hz
Threshold
F
on
F
off
0
FA2/FA4
Output
frequency
C042/C045
C043/C046
ON
t
Hz
Thresholds
F
on
F
off
0
FA3/FA5
Output
frequency
C042/C045
C043/C046
ON
ON
t
Hz
Thresholds
F
on
F
off
F
on
F
off
0