OMRON | Mitsubishi
Home >> Industry News >> News >> Text
Latest News
This month TOP10
Power Controllers
http://www.saleplc.com
Articles Entry:LKong Source:Network Published Time:2011-6-9
Power Controllers

OMRON provides single-phase/three-phase Power Controllers with a phase control system and Multi-channel Power Controller that enable high-precision temperature control with optimum cycle control.



Heater Control Types

 

Heater control consists of manual control, control using temperature controller and control using multi-loop controller.

 

G3PX Control Methods

 

G3PX control method consists of analog contro, ON/OFF control, two-position control and manual control.
 

Analog Control


The change in current output of the Temperature Controller between 4 and 20 mA is used for precise heater control by the G3PX,which outputs smoothly adjusted power. Fine adjustments of the heater temperature are possible with external or internal duty setting.

 


ON/OFF Control


The voltage output of the Temperature Controller is used for ON/OFF heater control. Fine adjustments of the heater temperature are possible with external or internal duty setting.


Two-position Control


The high level and low level of the output are freely set with an external variable resistor, either of which is selectable with the relay output of the Temperature Controller.


Manual Control


Output adjustments are possible with an external variable resistor.


ON/OFF Control

Enables noiseless temperature control at low cost with no complicated maintenance work required.


Cycle Control

Noiseless, high-speed response


Optimum Cycle Control (High-accuracy zero-cross control)

Multi-channel heater control using communication. High-speed response with no noise.


 


Phase Control (Single-phase Model)

Highly accurate temperature control enables each heater to withstand long use.


 

Power Controller Glossary


Phase Control


Output is varied at half-phase intervals. Therefore, highly accurate temperature control is possible.


The following is an example of a waveform in single-phase control.

 

Waveform for single-phase control


Three-phase models use a three-arm phase control method.

  • The change in current output of the Temperature Controller between 4 and 20 mA is used for analog control of the output power of the G3PX.

This function suppresses heat shock and ensures fine control without being influenced by external disturbance. As a result, each heater can withstand long use.

 


Duty Setting


As shown in the following graphs, the change of output can be adjusted with an internal or external variable resistor.


In the case of an electric oven, overshooting may result by using a heater with a capacity that is excessively high for the size of the oven.


By adjusting the duty-setting variable resistor, the overshooting can be suppressed.
For example, if a duty of 60% is set for a 5-kW heater, a maximum of 3 kW will be input into the heater. Thus, it operates as a 3-kW heater.

 


Duty Setting All G3PX Single-phase Models

 

Duty Setting All G3PX Single-phase Models

 


All G3PX Three-phase Models

 

All G3PX Three-phase Models

 


Soft-start


This function suppresses the inrush current that is caused when the load is turned ON, thus ensuring smooth starting of the load.


This function is especially effective for loads that involve high inrush current, such as halogen lamps.


The following is an example of a waveform in single-phase control.

 

Waveform in single-phase control

 


Base-up


This function briefly keeps the output of the G3PX turned ON after heating when the input signal is OFF.


This is effective for a smooth start of equipment that is slow in initial heating operation.

 


Constant Current


If the load has an extremely high inrush current, the extended soft-start function cannot suppress the inrush current. The constant-current function suppresses the inrush current automatically, thus protecting the heater and system from damage.

 


Connection Examples of Single-phase G3PX and Temperature Controller

  • The soft-start time is adjusted between 0.5 and 10 s, thus enabling the heaters to withstand long use.

  • If a single Temperature Controller is in control of more than one heater, by making a proper duty setting, the difference in temperature between the heaters can be improved. (Connection Example 2)

Note: The temperature at point B can be higher than that at point A due to thermal interference. In that case, make the duty set value for heater B smaller than that for heater A so that there will be no difference in temperature between points A and B.

 

Connection Examples of Single-phase G3PX and Temperature Controller

 


Connection Example 1.
Duty Change Using Voltage-output Temperature Controller and One G3PX

 

Duty Change Using Voltage-output Temperature Controller and One G3PX



Connection Example 2.
Duty Change Using Voltage-output Temperature Controller and Multiple G3PXs

 

Duty Change Using Voltage-output Temperature Controller and Multiple G3PXs



Connection Example 3.
Temperature Control Using Temperature Controller with Current Output of 4 to 20 mA and G3PX

Temperature Control Using Temperature Controller with Current Output of 4 to 20 mA and G3PX



Connection Example 4.
Duty Change Using Temperature Controller with Current Output of 4 to 20 mA and G3PX

Duty Change Using Temperature Controller with Current Output of 4 to 20 mA and G3PX



Connection Examples of Three-phase G3PX and Temperature Controller


The soft-start time is adjusted between 0.5 and 10 s, thus enabling the heaters to withstand long use.


If a single Temperature Controller is in control of more than one heater, by making a proper duty setting, the difference in temperature between the heaters can be improved. (Connection Example 2)


Note: The temperature at point B can be higher than that at point A due to thermal interference. In that case, make the duty set value for heater B smaller than that for heater A so that there will be no difference in temperature between points A and B.

 

Connection Examples of Three-phase G3PX and Temperature Controller

 


Connection Example 1.
Duty Change Using Voltage-output Temperature Controller and One G3PX

 

Duty Change Using Voltage-output Temperature Controller and One G3PX


Note: Turn the Internal DUTY Adjuster fully to the right.

 


Connection Example 2.
Duty Change Using Voltage-output Temperature Controller and Multiple G3PXs

 

Duty Change Using Voltage-output Temperature Controller and Multiple G3PXs



Connection Example 3.
Temperature Control Using Temperature Controller with Current Output of 4 to 20 mA and G3PX

Temperature Control Using Temperature Controller with Current Output of 4 to 20 mA and G3PX



Connection Example 4.
Duty Change Using Temperature Controller with Current Output of 4 to 20 mA and G3PX

 

Duty Change Using Temperature Controller with Current Output of 4 to 20 mA and G3PX


Note: Turn the Internal DUTY Adjuster fully to the right.

Related News More about Articles