Protection against thermal damage caused by overloads on machines (transformers, motors or generators).

The thermal capacity used is calculated according to a mathematical model which takes into account:

• current RMS values
• ambient temperature
• negative sequence current, a cause of motor rotor temperature rise.

The thermal capacity used calculations may be used to calculate predictive data for process control assistance.

The protection may be inhibited by a logic input when required by process control conditions.

Released for:Schneider Electric United Arab Emirates