Relay of current protection of electric motors of the RTZE series

At indirect connection via transformers of current of the RTZE-2.5, RTZE-5 relay can be used in lines on any tension.

The relay exercises control of currents in three phases of the electric motor and at identification of the inadmissible modes disconnects it.

Shutdown happens in the following emergencies:

• at an overload on current;
• when underloading on current;
• at not full-phase operating mode (break of a phase);
• at an inadmissible distortion of phases on current.

Protective shutdown is carried out by disconnection of a chain of management of the electromagnetic actuator (contactor).

The relay provides:

• regulation of settings of the maximum Imax, minimum Imin of current and imbalance of currents of Dmax of the electric motor;
• regulation of settings of a delay of operation of protective shutdown of Tmax, blocking of operation of protection at start-up Tp, delays on inclusion at breaks of power supply Tsz, delays on automatic repeated start-up Tpv with programmable number of attempts of repeated start-up of Npv;
• indication of the reason of an emergency shutdown;
• registration of starting current of Ip and time of an exit to the TV mode of the controlled electric motor;
• preservation in memory of information on quantity of normal and emergency shutdowns of the electric motor, and also controlled currents and a cause of accident at the time of an emergency shutdown (eight last on time of emergency shutdowns).

At connection of a number of additional devices (are delivered upon the demand of the customer) relays provide:

• turning on of the external signaling device at achievement of the preemergency and emergency modes (KS module);
• turning on of the external LED indicator at achievement of the preemergency and emergency modes (IS module);
• blocking of start at decrease in resistance of leakage of windings of the electric motor is one case lower than admissible level (M1 module).

The relay is manufactured nine face values: 2.5, 5, 12,5, 25, 50, 125, 250, 500 and 1250, the settings corresponding to limits on current in amperes.