Precautions for Correct Use of Power Controllers

Load

Only resistive loads can be connected to the G3PX.

Transformer Loads.
The primary side of a transformer is an inductive load. Therefore, do not control it directly.

Mounting

The Three-phase, 60-A G3PX weighs 5 kg. Dropping the G3PX when it is being mounted may result in injuries.

Mounting Procedure

Vertical Mounting

Note:In the case of flat mounting, the 30% derating of the load current is required.

1. Installation Space between Power Controllers

Panel Mounting Conditions

2. Relationship between Power Controllers and Ducts (or Other Airflow Obstructions)

Height of ducts (or other airflow obstructions)

Do not surround the Power Controller with ducts; otherwise, the heat radiation of the Power Controller will be adversely affected.

Countermeasure 1

Use short ducts.

3. Ventilation

Note:

1.If the air inlet or air outlet has a filter, clean the filter regularly to prevent it from clogging and ensure an efficient flow of air.

2.Do not locate any objects around the air inlet or air outlet; otherwise, the objects may obstruct the proper ventilation of the control panel.

3.A heat exchanger, if used, should be located in front of the G3PX to ensure the efficiency of the heat exchanger.

Please reduce the ambient temperature of G3PX.

Note:The rated load current of the G3PX is measured at an ambient temperature of 25 or 40°C.

The G3PX uses a semiconductor to switch the load. This causes the temperature inside the control panel to increase due to heating resulting from the passage of electrical current through the load. To restrict heating, attach a fan to the ventilation outlet or air inlet of the control panel to ventilate the panel. This will reduce the ambient temperature of the G3PX and thus increase reliability.(Generally, each 10°C reduction in temperature will double the expected life.)

Example:

Note:

Wiring

Make sure that the lead wires are thick enough according to the current.

Be sure to turn off power to the G3PX when wiring. The G3PX has current leakage although the G3PX is turned off if the power supply is connected to the G3PX, which may give an electric shock.

Do not wire power lines or high-tension lines along with the lines of the G3PX in the same conduit, otherwise the G3PX may be damaged or malfunction due to induction. Be sure to wire the lines of the G3PX separated from power lines or high-tension lines or laid in an exclusive, shielded conduit.

Tightening Torque

Apply the following tightening torque.

Output terminal:

Terminal block:

Be sure to protect the terminals with the protective cover after wiring.

Wiring for Error Detection

If a contactor is employed and operated with the relay output signal of the G3PX for error detection, make sure that the G3PX is closer to the power supply than the contactor.

Instruments

The instruments are used for displaying root-mean-square voltage and current values of the AC circuitry.

Operation Monitoring

The level indicator just indicates the phase of the load and it is not highly precise.

Duty Setting

There is a decrease in ramp if the internal DUTY adjuster is turned counterclockwise.

If the External DUTY Adjuster is used, set the Internal DUTY Adjuster to 100%.

CT Unit

The CT Unit varies with the G3PX-series model. Use the following
CT Units in combination with the G3PX models.
G3PX-2[]0EH Series: G32X-CT[][]
G3PX-2[]0EHN Series: G32X-CT[][]HN
G3PX-2[]0EC Series: G32X-CT[][]C
G3PX-2[]0D[][] Series: G32X-CT[][]C

If any of the following models is used and the actual load current is50% of the maximum rated load current or lower, increase the number of turns of the wire around the CT Unit.

G3PX-20EHN Series (multi-heater open circuit detective models)
G3PX-20EC Series (constant current)
Three-phase Models

For example, make two turns if the actual load current is 50% of the maximum rated load current and four turns if the actual load current is 25% of the maximum rated load current.
If the G3PX is a constant current model, do not increase the number of turns of the wire around the CT Unit excessively, otherwise the overcurrent detective function may operate by mistake.

External DUTY Adjuster

Use the External DUTY Adjuster with a resistance of 2 kΩ or that with a resistance of 3 kΩ according to the G3PX-series model in use.

Refer to the following combinations.

Base-up Function

EUN, DU, and DH Models

The base-up output of the G3PX with a temperature controller output of 0 mA (i.e., the temperature controller is turned off) and that of the G3PX with a temperature controller output of 4 mA are different from each other.

Power Device Cartridge

Do not apply power to the G3PX with the Power Device Cartridge dismounted.

Heater Open Circuit Detection

EH and EHN Models

The heater open circuit detective function is not available for detecting the phase less than the following.

DH and DC Models

A voltage output of 70% min. is required for heater burnout detection.

Power Supply

Single-phase Models Only

Do not apply 200 V to the 100-V terminals, otherwise the thermal fuse of the built-in transformer will be blown and the G3PX will not operate.

Single-phase Power Supply

(Three-phase Models Only)

The single-phase power supply circuit shown in the following diagram cannot be used.

Others

It is not possible to use three single-phase models for three-phase load control. Always use a three-phase model for control of three-phase loads.

If a three-phase power supply is used for single-phase models operating in parallel, make sure that the two phases supplied to all the single-phase models are the same. Not doing so may result in burnout detection, overcurrent detection, or alarm malfunction. Consult with your OMRON representative if such use is required.

Explanation

The 20-A and 40-A models use a triac on output elements.Fundamentally, triacs are easily influenced by power supply distortion, in which case the output may become unstable. (The 60-A models use a thyristor, and so are virtually not influenced by power supply distortion.) Power supply distortion tends to occur if the power supply capacity is insufficient when multiple power controllers are used. In particular, if they are used with three-phase open-delta wiring, power supply distortion may occur across the phases, resulting in malfunctions. If distortion is a problem, use the power controllers together on one phase as shown in the diagram above.

With three-phase models, the output voltage may become unstable if the balance of a three-phase load is lost. Therefore, use the power controllers with a load current balance ratio of 0.9 or better.

For three-phase models, do not incorrectly wire the R, S, and T phases of the main circuit wiring. Doing so will cause abnormal operation. After connecting the power controllers, confirm proper operation before using the system.

Checking Operation

Set the output voltage to approximately 50% and check that the voltage is almost the same between the phases. Variation will occur in the output voltage if the phase sequence is incorrect.

DH and DU Models

The detection sensitivity will differ. Correctly set the star/delta selector.