Basler Electric BE1-50 - Manual (Page 10)

In this application, the two leads of each phase of the protected motor or generator are passed through
the window of the same associated phase current transformer so that the resulting secondary current is
zero under normal operating conditions.
Figure 1-2. Self-Balancing Differential Protection
Combination with Other Protective Devices
Because BE1-50 relays can provide complete phase and ground fault protection in one unit (and with
independent settings for phase and ground), they are often used to supervise other relay functions. In
distance protection, BE1-50 relays can be used to prevent misoperation for light loading conditions by
requiring a minimum current level before enabling the distance relay. As a fault detector, they are
particularly effective because of their sensitivity, speed, and dropout ratio.
MODEL AND STYLE NUMBER
BE1-50 electrical characteristics and operational features are defined by a combination of letters and
numbers that make up the style number. Model number BE1-50 designates the relay as a Basler Electric
Instantaneous Overcurrent Relay. The model number, together with the style number, describes the
options included in a specific device and appears on the front panel, draw-out cradle, and inside the case
assembly.
The style number identification chart for the BE1-50 relay is illustrated in Figure 1-3.
1-2 BE1-50 General Information 9171000990 Rev F