SRH1 Series


Single-Phase Solid State Relays (Integrated Heatsink, Top/Bottom Terminal Type)

The SRH1 series single phase solid state relays feature integrated heatsinks for excellent heat dissipation efficiency, and the standard top/bottom terminal layout allows easy installation. The voltage input type models are available in zero cross turn-on and random turn-on models. The current input type models offer both phase control (equal power/equal phase) and cycle control (fixed/variable) options. The units support both DIN rail mount and panel mount methods for easy installation.

Main features


  • High heat dissipation efficiency with ceramic PCB
  • Input indicator (green LED)
  • DIN rail mount or panel mount installation

[Voltage input type]

  • Zero cross turn-on, random turn-on models available

※ The SRH1 series has been updated (SRH1-ㅁㅁㅁㅁ-N). Please check specification details before use.

[Current input type]

  • Phase control (equal phase/equal power) and cycle control (fixed/variable)
  • High dielectric strength: 4,000 VAC

※ The SRPH1 series has been updated (SRH1-Aㅁㅁㅁ-N). Please check specification details before use.

  • Efficient Heat Dissipation

  • Input Indicator

  • Screw Mount

  • DIN Rail Mount

  • Dielectric Strength (Select Models)

SSR Series Change Notice (SRPH1 => SRH1)

Single phase analog (current) input type solid state relay series has been changed/replaced.

Previous models New models
SRPH1-A220 SRH1-A220-N
SRPH1-A230 SRH1-A230-N
SRPH1-A260 SRH1-A260-N
SRPH1-A420 SRH1-A420-N
SRPH1-A430 SRH1-A430-N
SRPH1-A460 SRH1-A460-N

4,000 VAC High Dielectric Strength (Current Input Type Models)

The high dielectric strength of 4,000VAC provides durable and stable performance.

High Heat Dissipation Efficiency with Ceramic PCB

Ceramic PCBs offer better electrical isolation and thermal conductivity compared to metal core PCBs, offering better heat dissipation efficiency.

Check Operation Status

Easily check the operation status of the unit with the input indicator (green LED).

Zero Cross Turn-On/Random Turn-On Models Available (Voltage Input Type)

  • Zero Cross Turn-On

    The relay switches ON/OFF when the voltage reaches the zero-crossing point of the sine wave. This method minimizes surge current and inrush current, and is ideal for most common industrial loads.

  • Random Turn-On

    The relay opens or turns on immediately when the input signal is applied and turns off when the signal is removed. This method allows phase-control applications requiring precise power control.

Phase Control and Cycle Control with Analog Current Input (Current Input Type)

Precise control is possible through phase control (equal phase/equal power) or cycle control (fixed/variable) using 4-20 mA current input.

Phase control

  • Output waveform of phase control

    Phase control
  • Power equality division type

    Power equality division type
  • Phase equality division type

    Phase equality division type

Cycle control

  • Fixed cycle

    Controls continuously the number of full cycle which is supplied to load every 1sec. by being proportional to control input(4-20mA).

    Fixed cycle
  • Variable cycle

    Controls fast and accurately the subject with optimized the number of AC voltage cycle which is supplied to load by being proportional to control input. (4-20mA).

    Variable cycle

Various Installation Methods

The solid state relay units support both DIN rail mount and panel mount methods providing more installation flexibility.

  • DIN Rail Mount

    DIN Rail Mount

  • Panel Mount

    Panel Mount

Developed & Designed By:
Eng. Haitham Abdelraouf @2021