Hitachi L100 300, SJ 300, L100 300 4-2 Constant Temperature Control, Constant Temperature Control, Fig. 4-2 Example of

SJ100/L100 / PID / 15

4-2 Constant Temperature Control

In the case of constant flow control shown in the previous section, output frequency of the inverter

increases if the feedback value is smaller than target value, and output frequency of the inverter

decreases if the feedback value is bigger than the target value. However, in the case of constant

temperature control, this is the opposite. The inverter increases its output frequency to drive a cooling fan

much faster when the temperature feedback signal is higher than target temperature, for example. Below

you can find an example of how to configure such an application.

In this case (targets are 20 & 30 degrees), the

settings would be as follows:

Function Number Function Name Input Remarks

Integrated Operator DOP, DRW Under PID Control Mode Data

F01 Monitor

mode

Target 0 20 Directly input “20 [deg]” because

scale conversion ratio is given

A01 Target input origin setting 02 Operator

A11 F31 Feedback value input corresponding %

for lower acceptance level 100 100%

A12 Feedback value input corresponding %

for upper acceptance level 00%

A13 Feedback value input

for lower acceptance level setting 00%

A14 Feedback value input

for upper acceptance level setting 100 100%

A21 F11 Target 1 30 30 deg

A71 F39 PID mode selection 01 PID Mode ON

A72 P-gain adjustment -Depends on each application

A73 I -gain adjustment -

A74 D-gain adjustment -

A75 PID scale conversion ratio setting 0.5 100% when 50 [deg]

A76 Origin of feedback signal selection 01 Feedback from OI-L terminal

30deg.

50deg. 100

20deg.

Feedback value range setting

Fig. 4-2 Example of

Constant Temperature Control

L100/

SJ100

Target

Feedback

Transducer

0 - 10V

(50 degrees at 10V)

Temperature sensor

Temperature

:Either 20 or 30 degrees constant

Fan

Motor

Multi-stage Target

10V0100%

06V

60%

40%