Cheap yet reliable industrial solid state relay (SSR), is available with 80 Amp, 100 Amp and 120 Amp load current. This DC to AC SSR is an ideal module for automatic control system like petrochemical equipment, pharmaceutical machines, food machines, packaging machines, etc., especially suitable for corrosive, humid, dusty and other harsh environment.
|On-State Voltage Drop
|Off-State Leakage Current
||1000MΩ/ 500V DC
||-20 ~ +70℃
Dimension (Unit: mm)
1. For the resistive load, it can not exceed 60% of the rated current of the SSR.
2. For the inductive or capacitive load, it can not exceed 40% of the rated current of the SSR.
3. For the electric motor, it can not exceed 20% of the rated current of the SSR.
4. Proper radiator or heat sink should be equipped for the industrial solid state relay. If the load cooling condition is not good, it is necessary to leave some margin. Avoid the load short circuit because over current and short circuit are the main causes for permanent damage of the internal SCR of the SSR.
5. Over current protection: Using fast fuse and air switch is one of the methods for over current protection; fuse is also available for small capacity.
6. Over voltage protection: It can adopt the parallel voltage-dependent resistor (MOV). The MOV area decides the absorption power, and its thickness decides the protective voltage value. Generally, 471/10D voltage-dependent resistor is suitable for 220V series SSR, 681/10D voltage-dependent resistor for 380V series SSR, and 821/10D voltage-dependent resistor for 480V series SSR.
Tips: Usage of Solid State Relay – Capacitive Load
Although the capacitive load is not very common, the solid state relay will also be used for it sometimes. Much attention should be paid to the low-impedance capacitive load, and the di/dt of the SSR can not be exceeded. If there is no extra limitation to the impedance, the capacitive load di/dt can approach infinity during powering. It is very useful way to limit the capacitive load di/dt by zero-crossing switching type SSR. When using a solid state relay, the safety range of maximum blocking voltage should be considered. If it discharges near the peak of the line voltage, it will cause a destructive di/dt value, which will easily make the load breakover, so the transient voltage of capacitive load must be limited. For large capacitive load, it is necessary to limit the di/dt within the stipulated value by series circuit impedance, which can protect the SSR from suffering the accidental yet unavoidable high transient voltage.