39
Vol. 2.6 © 2020 Hanbell Precise Machinery Co., Ltd. All rights reserved
Factory default setting of the dead band value is 2%, therefore an input current change of
0.32mA (2%) is required to make minimum movement.
%
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5
Dial
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
Deadband value (sensitivity) setting: The lower the set value, the more sensitive it will be.
Excessive sensitivity will cause actuator “hunting” (moving up and down while unable to
positioning). But if the deviation range on operation settings of the system unit controller is
too small, it will also lead to the same “hunting” problem. Therefore, when “hunting” occurs,
please make sure that both settings are appropriate.
Warning
：
：
：
：
Setting of extremely low dead band value may cause actuator “hunting”.
Warning
：
：
：
：
Only authorized and certified technicians are allowed to change this setting
.
3.2.4 Duty cycle
This setting could be used as periodic setting. The settings for operating time and rest time
of the actuator are based on the standards of IEC (International Electrotechnical
Commission), IEC34-1 as follows:
Start frequency=operating time/(operating time + rest time)*100%
Rest time=operating time*(1-start frequency)/start frequency
Example: Actuator duty cycle (start frequency) on the compressor of 50 Hz is 70%, the
operating time is 21 seconds:
Rest time = 21 * (1-70%) / 70% = 9 seconds, so when the controller is under command
to carry out:
1. Full capacity control (IGV=0%
→
100% or 100%
→
0%), time interval should be at least
21+9=30 seconds.
2. Partial capacity modulation, the interval time is:
Interval time= | Capacity difference% | *(21 +9)
Example :IGV=65%
→
55% interval time=
｜
65%-55%
｜
*(21+9)=3 seconds
Note
：
It is complicated to split command time into many parts in control logic. Therefore, if
the operation opening for chilled water control is
≦
10% for each operations, and the
chilled water response cycle is about 30~60seconds, then an operating time interval
of 30 seconds can be used.
Caution
：
In order to prevent accumulated heating of the motor due to frequent operations, it
is advisable to set the start frequency to maximum 3 times/minute.
