Technical Specifications

FAQ

1. What type of contactor is LC1G400EHEN?

LC1G400EHEN is a high-power three-pole contactor from the TeSys Giga range, designed primarily for industrial power switching and motor control applications. It has three normally open main contacts and is rated for 400 A under AC-3 conditions at up to 440 V AC. The contactor is intended for applications where large motors and high-current loads require reliable electrical switching. It can be used in motor starters, industrial production equipment, pumps, fans, compressors, conveyors, HVAC systems, and other automation equipment. Its wide-range 48–130 V AC/DC control coil also allows it to be integrated into different industrial control circuits without requiring a narrow fixed coil voltage.

2. What is the AC-3 current rating of LC1G400EHEN?

The AC-3 rated operational current of LC1G400EHEN is 400 A at an operational voltage of up to 440 V AC. AC-3 is a common utilization category for controlling squirrel-cage induction motors, particularly during normal motor starting and stopping operations. When selecting this contactor for a motor application, the actual motor current should be compared with the contactor rating under the corresponding operating conditions. Motor power, supply voltage, ambient temperature, starting frequency, and load characteristics should also be considered. The 400 A AC-3 rating should not be interpreted as meaning that every 400 A motor application is automatically suitable, because the complete operating conditions determine the correct contactor selection.

3. What control voltage does LC1G400EHEN use?

LC1G400EHEN uses a wide-band electronic control coil rated for 48–130 V AC/DC. The same contactor can therefore operate with either AC or DC control power within the specified voltage range. This feature is useful in industrial automation systems where control circuits may use different power architectures. The actual control voltage should always be checked before installation, and the control circuit should be capable of supplying the required coil power. When the contactor is controlled by a PLC, relay, or other automation controller, the output device must be electrically compatible with the coil circuit. If the controller cannot directly handle the coil circuit, an appropriate interface relay or switching device should be used.

4. Can LC1G400EHEN be used for PLC-based motor control?

Yes. LC1G400EHEN can be incorporated into PLC-based motor control systems and is suitable for applications where the PLC needs to control a high-current motor circuit. The PLC normally operates the contactor through its control circuit rather than switching the motor current directly. A typical control system may include the PLC output, an interface or relay circuit where required, the LC1G400EHEN coil, motor protection equipment, and the motor power circuit. Interlocking logic can also be implemented to prevent unsafe simultaneous operation of forward and reverse contactors or other conflicting switching devices. During system design, the PLC output specifications, coil voltage, motor current, overload protection, emergency-stop circuit, and control logic should all be evaluated together.

5. What should be considered when wiring LC1G400EHEN in a motor starter?

The main power circuit should be designed according to the motor’s rated current, supply voltage, starting characteristics, and applicable electrical installation requirements. The three main poles are used to switch the three-phase motor supply, while the control circuit operates the contactor coil. Properly rated cables, terminals, protective devices, and overload protection should be selected for the actual load. Connections must be securely tightened because loose terminals can increase electrical resistance and generate localized heating during high-current operation. Before energizing the system, it is advisable to verify phase connections, control wiring, protective devices, interlocks, and motor protection settings. A controlled commissioning procedure should then be performed to confirm that the contactor closes and releases correctly and that the motor operates normally.

6. Why might LC1G400EHEN fail to close when a start command is given?

A failure to close can originate from either the control circuit or the contactor itself. The first troubleshooting step is to verify whether the correct voltage is present across the coil when the start command is active. If the coil voltage is missing or too low, the control circuit should be checked for PLC output problems, blown control fuses, open emergency-stop circuits, incorrect interlocks, faulty auxiliary contacts, loose wiring, or an incorrectly configured control relay. If the specified control voltage is present but the contactor does not close, the coil, electronic control module, and mechanical operating mechanism should be investigated. It is also important to check whether an overload or safety circuit is intentionally preventing the contactor from operating. Troubleshooting should begin with measurements in the control circuit rather than immediately replacing the complete contactor.

7. What can cause overheating of LC1G400EHEN during continuous operation?

Excessive heating can result from high load current, loose power connections, unsuitable cable sizing, poor electrical connections, abnormal contact resistance, insufficient ventilation, or operation outside the intended electrical conditions. Because LC1G400EHEN is designed for high-current applications, the condition of the main terminals and power connections is particularly important. A loose connection can create additional resistance and produce localized heat even when the overall load current does not appear unusually high. During troubleshooting, the operating current should be measured on all phases and compared with the expected motor load. The terminals should also be inspected for discoloration, signs of overheating, oxidation, or mechanical looseness. If one phase shows significantly different heating or current behavior from the others, the associated wiring, contact path, and motor circuit should be investigated in detail.

8. How should LC1G400EHEN be maintained in a high-current motor control system?

Maintenance should focus on the electrical connections, contactor operating behavior, control circuit, auxiliary contacts, and surrounding motor protection equipment. During scheduled inspections, technicians should check for loose terminals, abnormal heating, unusual operating noise, delayed closing or release, contact welding, and visible signs of electrical stress. The motor load should also be monitored because excessive current, repeated overloads, or unusually frequent starting can increase electrical stress on the contactor. The control voltage should remain within the appropriate operating range, and the PLC or relay control circuit should be checked if intermittent operation occurs. For equipment operating continuously or under heavy-duty conditions, maintenance intervals should be determined according to the actual switching frequency, load characteristics, environmental conditions, and operating history rather than relying only on a fixed calendar interval.