Home > Product Groups > Power Control (Thyristors) > Thyristor Power Controllers > Single Phase (1PH) Load > How to size a 1PH thyristor? > 

 

How to size a Single Phase Thyristor

 

The formula below provides a simple method to calculate the thyristor current for typical resistive loads. The calculated value of I should then be multiplied by 1.2 (safety margin) to allow for variations in supply voltage and other tolerances of the load. 

 

Single Phase (1PH)

 

Thyristor current (I) = Power (WATTS)

                                      V

Example: A 9kW load across 240V AC

 

              I = 9000 = 37.5A

                    240

 

If we apply the safety margin of 20%, the thyristor current equals:

37.7 x 1.2 = 45A

 

We can therefore use a 45A, 240V AC thyristor unit

 


 

See Also: Single Phase Selection Guide 

              Single Phase Thyristor Controllers