How can I choose the electrical protection of a PLC?

The circuit-breaker must protect the PLC against high inrush currents on power-up and overloads during nominal operation.

• Magnetic protection (inrush current on starting) is provided by a iC60 Curve D circuit-breaker (see below for the choice of rating).
• Thermal protection must be provided by a thermal overload relay rated at the transformer secondary In.

Selection of circuit-breaker:
In the power supply module characteristics, it is the It current on activation that interests us (for each type of power supply).

Example:
BMXCPS2000 ( see product data sheet )
It = 0.06 A at 240 VAC [Inom = 0.31 A]
The important operating point is located 10 ms into the circuit-breaker trip curve.
At 10 ms, we have an inrush = It/10 ms = 0.06/0.01 --> 6.0 A per power supply.

For product characteristics regarding your PLC. please visit our website www.se.com/uk where you can find product Data sheets.

For further information about the protection that Schneider Electric can offer , please access to the next link:

Electrical Protection | Electrical Protection and Control | Schneider Electric UK

Contactors and Protection Relays | Schneider Electric UK

Released for: Schneider Electric UK