Solid-state Contactors

They are complete units which consist of a solid-state relay plus optimized heatsink, and are therefore ready to use. They offer defined rated currents to make selection as easy as possible.

They can easily be installed onto a standard mounting rail, or they can be mounted on support plates with fixing screws.


How to select the right solid-state contactors ?

The semiconductor contactors are selected on the basis of details of the power system, the type of load and the ambient temperature conditions.

As the semiconductor contactors are already equipped with an optimized heatsink, the selection process is considerably simpler than that for solid state relays (SSR).

The following procedure is recommended:

  • Determine the rated current of the load and the mains voltage
  • Select a semiconductor contactor with the same or higher rated current than the load
  • Check the correct contactor taking into account the design conditions

celduc relais‘ complete range of Solid-state Contactors

Our solid-state contactors are available in different versions :

  • single-phase solid-state contactors,
  • three -phase solid-state contactors,
  • diagnostis solid state contactors,
  • three -phase AC softstarters,
  • single phase angle controllers.

Single-phase versions

Version for resistive loads, “zero-point switching” (also named « zero-cross »)



Version for most types of load, “zero-point switching” (also named « zero-cross »)


Version for inductive loads, “instantaneous switching” (also named « random » or « instant switching »)


Three-phase versions

 The three-phase solid-state contactors for resistive loads up to 64A (@ 40°C) and for motor loads up to 32A (@ 40°C) are available with three-phase control (suitable for star circuits with connection to the neutral conductor or for applications in which the system requires all phases to be switched).

SGT8658502 – 3 x 24A AC-51 – 3 x 12A AC-53 – 24-520Vac – Ctrl 24-255Vac/dc

SGT8698503 – 3 x 48A AC-51 – 3 x 32A AC-53 – 24-520Vac – Ctrl 24-255Vac/dc

SGT8698504 – 3 x 64A AC-51 – 3 x 32A AC-53 – 24-520Vac – Ctrl 24-255Vac/dc

Our sightpac® range (compact 45mm version) is also available in a « ready to use » version with integrated heatsink.

SMT8628521 – 3 x 14A AC-51 – 3 x 5A AC-53 – 24-520Vac – Ctrl 24-255Vac/dc


Diagnostics relay

Our range of diagnosis relay comes in celpac® housing « ready to use » with our SILD range.

These relays inform the user of the load status (resistive load), the output of the relay and the network through an NC (Normally Closed) diagnostic contact. The diagnostic function does not require an external power supply (celduc® patent) The contacts of various relays can be placed in a series.

Three -phase AC softstarters

celduc® relais has designed a range of soft starters for AC motors up to 26 kW (wired in Delta) supplied with built-in heatsink.

SMCW range

Single phase angle controllers

Our Six4 range is in celpac® housing (ready to use). This range is designed for resistive loads.