Top 10 Costliest Mistakes In SCR Power Controller Design: Part 4

Our engineers have compiled a list of the "Top 10 Costliest Mistakes In SCR Power Controller Design." Check back each week for two more entries in the series, and contact us for more information.

#3. Not having a spare on hand

While SCRs will give years of service if properly cooled and kept clean, inevitably they will fail.  When this failure happens, losses from production, downtime, or scrapped product are often tenfold the cost of having a spare controller readily at hand. 

#4. Placing a mechanical contactor on the load side of the SCR

Customers often desire to switch loads using a mechanical contactor for safety or load trimming.  When a mechanical contactor opens and closes, the contacts do not make simultaneously.  If the contactor is opened under power, kickback voltages may be sent to the SCR which can cause premature failure. 

Furthermore, when an SCR controller uses power or current feedback, the controller may momentarily apply full power to your load when the contactor is switched on causing damage to the load, saturation of a downstream transformer, or blown fuses.