PCB Mount Solid State Relays from celduc relais
May 7, 2025
Industrial applications such as professional food equipment, medical equipment, and renewable energy systems require devices with smaller footprints. Solid state relays (SSR) provide the advantages of long service life expectancy, no contact bounce or arching, zero-crossing capability, low power input, and high resistance to shock and vibration. In addition, PCB mount solid state relays provide space savings and have specific power requirements.
Celduc® PCB mount solid state relays offer the advantages of several input and output configurations for both AC and DC switching applications.
For applications requiring ratings:
– In AC : from 1 to 30A / 12-280Vac or 24-600Vac
– In DC : from 1 to 10A / 0-200Vdc
The power components range is from 16A to 75A.
Main advantages of celduc’s product range
1-High performance
The optimisation of the control cabinet infrastructure is our daily motivation. For this we have built up decades of technical expertise and a broad understanding of the market. Our range impresses with reliable, safe, and durable products.
2-Unique Technology on the market
Some of our Through Hole Solid State Relays are manufactured with back-to-back thyristors mounted on a ceramic substrate with bonded-wire connections : this is celduc’s fourth generation TMS² technology. This technology reduces thermal-stress and improves product life.
TMS² technology gives to celduc’s Solid State Relays a vey high life-time expectancy compared to the majority of products on the market. Celduc’s R&D makes regular improvement on our production process which increase constantly the number of cycles.
3-Built-in voltage protection
Some products are available with built-in voltage protection
4-Very high immunity to EMC disturbances
Electromagnetic compatibility (EMC) is the ability of electrical equipment and systems to function acceptably in their electromagnetic environment, by limiting the unintentional generation, propagation and reception of electromagnetic energy which may cause unwanted effects such as electromagnetic interference (EMI) or even physical damage in operational equipment.
celduc® PCB Solid State Relays have Very high immunity to EMC disturbances.
5-Solid state relays 100% tested
All celduc® SSR relays are tested for functionality and insulation. This guarantees 100% operation and reliability of the separation between the control and power circuits.
AC output models : from 1 to 30A / 600-1600Vpeak
SKA
SKA range can switch currents up to 5A of 230 or 400Vac and it has built-in voltage protection. This range is ideal for motor control applications, electrovalves and resistive loads.
SKB
SKB range can switch currents up to 5A, switch voltages of 230 or 400Vac and is only used for controlling standard industrial loads such as resistive loads.
SKL
The SKL range use TMS² techynology which reduces thermal stress and improves product service life. The power components range from 16A to 75A.
I²t is an expression of the available thermal energy resulting from current flow, the units for I²t are expressed in ampere-squared-seconds [A²s]. The I²t value for the SKL range is given up to 5000A², it means this range can withstand significant inrush currents. It is then possible to use circuit breakers for short circuit protection.
This range is ideal for motor or lighting control.
SKH
SKH range is a « ready to use » range of solid state relays for printed circuits. Each relay has a built-in heatsink and is suitable for application with a nominal current up to 10A @25°C.
SLA / SPA / STA
These models are 100% compatible with electromechanical relays.
AC ranges are available from 1 to 5A.
To view celduc’s SLA / SPA and STA ranges
DC output models : from 1 to 10A / 200Vpeak
SKD
DC Through Hole Solid State Relays using Bipolar Technology – Can switch currents up to 3A
DC Bipolar Solid State Relays are recommended for applications where a low control current is required.
SKLD
DC Through Hole Solid State Relays using Mosfet Technology – Can switch currents up to 10A
DC Mosfet Solid State Relays are ideal for applications requiring transient overcurrent withstand (motors).
Transils are used to protect against over-voltage on output and High voltage products are available on request.
SLD / SPD / STD
These models are 100% compatible with electromechanical relays.
DC ranges are available from 1 to 5A.
To view celduc’s SLD / SPD and STD ranges
Three-phase models
Celduc® relais also offers a range of three-phase solid state relays for PCB mounting.
SHT
The SHT range is a range of Three-phase solid state relays in a single low profile package for printed circuits and can switching currents up to 3x25A. Typical applications are Switching of medium power three-phase loads.
Celduc® also offers products with LED indicators that can be DIN Rail mounted
Typical applications
PCB Mount Solid State Relays are suitable for a very broad range of applications such as: heating control, motor switching, lighting control, vending machines, medical equipment, HVAC and appliances among many others.
Electrovalves, LEDs, contactors
A solenoid valve is an electromechanical device in a hydraulic circuit, which uses an electric current to generate a magnetic field and thus actuate a solenoid which controls the opening of the flow of fluid in a valve.
In these applications, the inrush current can be 4 times more than the nominal current : Id = 1,4xln
Key products are SKA range
Heating elements
Heating applications with temperature regulation need high frequency ON/OFF. Therefore Zero cross Solid State Relays are very well adapted for such application.
Standards give for AC-51 loads a reference with a starting current in cold conditions = 1,4 x the nominal current.
Id = 1,4xln
Key products are SKB and SKL ranges.
Infrared lamps or lighting
A large inrush current flows through some lamps (approx. 10 times higher than the rated current). You should select an SSR so that the peak value of inrush current does not exceed half the inrush current resistance of the SSR. In fact, when a repetitive inrush current of greater than half the inrush current resistance is applied, the output element of the SSR may be damaged.
Id = 10xln
Key products are SKH and SKL ranges.
Motors
Motor control has always been something difficult to tackle with as a motor is first of all an inductive type of load with high starting currents (approx. 8 times higher than the rated current)
Id = 8xln
Key products are SKH and SKL ranges.
What to take into consideration before connecting a relay to a PCB?
Decisions about connecting a relay to a PCB involve the operating conditions, construction, and the mounting type. Conditions including the load current, surge current, airflow and ambient temperature impact the size and spacing of solid state relays. A PCB mount solid state relay that carries five amps of load current and dissipating approximately five watts of power requires additional spacing because of the need for heat dissipation.
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