Industrial solid state relay can be selected in the load current range of 150 Amp, 200 Amp, 250 Amp and 300 Amp. This single phase SSR is DC control AC type, applicable for petrochemical equipment, pharmaceutical machines, food machines, packaging machines, plastic machines, CNC machine tool and other automatic control systems.
|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 – Inductive Load
Although AC solid state relay is cut off at zero current, there will be still some problems due to other causes. On the moment of zero current, the SSR will changeover (reverse current direction) at which the SSR does not conduct the current. All the transient line voltage is bridged over on the connection terminal, which produce a high dv/dt to make the SSR breakover at once, so as to have the SSR “lock up” state without release. Most of AC SSR has RC to enhance the capability against dv/dt. For DC inductive load, there will be high back EMF when it starts up. It can add the freewheeling diode in the two ends of load to make the DC solid state relay work reliable.