power supply conatctor by using Dc voltage

[techsudheer]

dear all,
all power conttactors will be on AC supply.... i want to run contactort by using AC/Dc supply... am using 48vdc.. is there any good fromule?

 

[chuckey]

Without any specific data its hard to be accurate, but the following must be held in mind. With an AC driven contactor "out" the magnetic path is broken by an air gap so when the voltage is applied, there is a big inrush current. When the contactor pulls in the magnetic path is complete so the current falls to 10% of the pull-in current. With DC the current is the same, in or out so if the contactor coil is not to over heat an "economy" resistor must be switched into the circuit. This is often done by using an auxially contact that is normally closed when the contactor is de-energised. To use on AC/DC, use a bridge rectifier and a smoothing cap so your "AC" is DC .
Frank

 

[kak111]

Contactor manufacturers catalogues has usually included tables for different categories for loads (AC/DC) and switching times etc.

For example.

Fuji SC contactors with AC-load
**broken link removed**

Fuji SC contactors with DC-load
**broken link removed**

Schneider / Telemecanique

p. 16. Definitions of Utilization Categories
p. 18 Contactor Selection for Utilization Category AC-3
p. 22 Contactor Selection for Utilization Category AC-1
etc.....etc............

https://stevenengineering.com/Tech_Support/PDFs/45TESYSCAT.pdf