Relé de Estado Sólido Trifásico 120A- KREST120C -Kayama

Technical Description

The Kayama KREST120C Three-Phase Solid State Relay is an electronic component designed for switching loads in three-phase electrical systems using solid-state technology.

The KREST120C has a stated rated current of 120 A and can be integrated into compatible electrical control and automation systems.

Its semiconductor technology performs switching without conventional mechanical power contacts.

Technical Characteristics

• Brand: Kayama
• Model: KREST120C
• Type: Three-Phase Solid State Relay — SSR
• Number of phases: 3
• Stated rated current: 120 A
• Switching technology: solid state
• Purpose: electronic switching of three-phase loads
• General application: electrical control and automation

Solid-State Technology

The KREST120C uses semiconductor components for electronic load switching.

This eliminates the physical movement of conventional power contacts during normal operation.

Proper electrical and thermal sizing remains essential to system performance.

Three-Phase Configuration

The KREST120C is intended for three-phase systems.

Before installation, system voltage, load current, load configuration, load characteristics, inrush current, control system, electrical protection and thermal conditions must be evaluated.

120 A Rated Current

The product has a stated rated current of 120 A.

Actual usable current depends on several factors, including:

• load type;
• operating current;
• starting current;
• surge current;
• ambient temperature;
• ventilation;
• thermal dissipation;
• switching frequency;
• duty cycle;
• mounting conditions.

Thermal Dissipation

Solid-state relays generate heat during current conduction.

Therefore, proper thermal management is essential, especially in high-current applications.

A suitable heat-dissipation system may be required depending on actual installation conditions.

Derating

Under unfavorable thermal conditions, the permissible operating current may need to be reduced.

This is known as derating.

High ambient temperature, poor ventilation and continuous-duty operation may require current reduction.

Load Characteristics

SSR sizing must consider the characteristics of the connected load.

Three-phase heaters, motors, transformers, inductive loads, capacitive loads and electronic equipment may behave differently.

Starting Current

Motors, transformers and certain loads can draw starting currents significantly above their normal operating current.

The KREST120C should therefore not be selected for these applications solely according to steady-state current.

Resistive Load Applications

When properly sized, the KREST120C may be considered for three-phase resistive applications such as:

• electric heaters;
• heating systems;
• ovens;
• heating chambers;
• automated thermal processes.

Motor Applications

Motor switching requires specific analysis of:

• rated current;
• inrush current;
• starting frequency;
• inductive load behavior;
• overload protection;
• short-circuit protection;
• phase protection.

The KREST120C does not replace dedicated motor-protection devices.

Automation System Integration

The KREST120C may be incorporated into compatible automation systems using PLCs, process controllers, temperature controllers and other industrial interfaces.

The exact electrical requirements of the control input must be confirmed before connection.

Electrical Protection

The SSR does not replace circuit breakers, fuses, surge protection, overload protection or required disconnecting devices.

Protection must be selected according to actual system conditions.

Failure Condition and Safety

Solid-state devices can fail in different modes, including conditions in which the output remains conductive.

Critical applications therefore require an independent means of disconnecting the load.

The KREST120C should not be used alone as a functional safety device.

Installation and Maintenance

Installation should be performed by technically qualified personnel.

Verify system voltage, load current, load characteristics, inrush current, control circuit, protection and thermal conditions before energizing.

Disconnect the system and confirm absence of voltage before maintenance.

Kayama Quality

The Kayama KREST120C Three-Phase Solid State Relay is part of Kayama's professional range of components for electronic switching, three-phase electrical control and automation.