Basler Electric BE1-BPR - Manual (Page 53)

9272000990 Rev J BE1-BPR Functional Description 4-1
SECTION 4 •FUNCTIONAL DESCRIPTION
GENERAL
BE1-BPR Breaker Protection Relays are microprocessor-based devices that provide breaker failure
protection, optional fault recording, and diagnostic monitoring of breaker wear and breaker resistor
overheating. This section describes the hardware and software functional descriptions.
HARDWARE FUNCTIONAL DESCRIPTION
BE1-BPR relays are available in a horizontal, 19-inch, rack-mount configuration or a vertical, panel-mount
configuration. Two latches secure the chassis assembly in the case. The chassis assembly can be
removed from the case by releasing the two latches and pulling the spring loaded, retracting handle on
the front panel. It is not necessary to disturb system wiring when removing a BE1-BPR relay from the
case. A transparent front cover protects the relay but allows access to frequently used front panel
controls.
The hardware functional description is divided into three categories: inputs, circuit operation, and outputs.
Inputs
There are five types of inputs to the BE1-BPR relay. They are:
• Operating Power
• Contact Sensing
• Current Sensing
• Keyboard
• Serial Ports RS-232/RS-485
Operating power for the internal circuitry is applied to the internal, isolated, switching power supply.
Nominal operating power is either 48/125 VDC or 125/250 VDC and is determined by the relay part
number shown in Section 1, General Information, Specifications.
Operating Power
Seven external contact sensing inputs accept external stimulus to initiate BE1-BPR relay actions. Voltage
applied to the contact sensing inputs must fall within the relay DC power supply input voltage range. If the
power supply of the relay has an ac source, a separate dc source must be used for the contact sensing
input voltage. Three contact sensing inputs (IN1 through IN3) are individually isolated. IN4 and IN5 are
isolated from other circuits but share a common return. IN6 and IN7 are also isolated from other circuits
but share a common return.
Contact Sensing
Monitored line and neutral currents are applied to internal current transformers (CTs) and stepped down
to internal circuit levels. The internal CTs provide isolation from the monitored line currents.
Current Sensing
A keyboard (illustrated in Section 3) provides limited local programming capability and the ability to select
a number of status and diagnostic menu screens.
Keyboard
Serial communication ports at the front and rear of the BE1-BPR relay provide complete programming
capability and remote access for diagnostics, relay setup, and relay control.
Serial Ports RS-232/RS-485
Circuit Operation
The microprocessor continually monitors itself to ensure proper operation. Separate, independent circuitry
monitors the power supply and the microprocessor to ensure that any problem in these areas
automatically takes the BE1-BPR off-line and activates the alarm output. Relay circuit functions illustrated
in Figure 4-1 are described in the following paragraphs.