Basler Electric BE1-BPR - Manual (Page 55)

9272000990 Rev J BE1-BPR Functional Description 4-3
Outputs from the contact sensing circuits are debounced by the microprocessor using programmable
recognition and debounce times. Debounce logic is programmable only through the communication ports.
Debounce Logic
Stepped-down inputs from each CT are converted to a voltage signal and filtered by a low-pass anti-
aliasing filter. The digitized input signal is then passed to the microprocessor for processing.
Anti-Aliasing Filter and Analog to Digital Converter
Each monitored current is digitized, digitally filtered, and the 50/60 hertz rms value for each input is calcu-
lated. The filtered value is compared to the appropriate pickup setting. If the filtered value is greater than
the pickup setting, then a fault detector logic flag (F1, F2, or F3) is set for use by the output logic section.
If the fault detector logic is programmed as an instantaneous overcurrent pickup (filter type 1 or 3), the
50PU LED is turned on. If the fault detector logic is programmed as a moving average current detector,
(filter type 2), the 50PU LED is not turned on.
Programmable Fault Detector Logic
Up to six programmable, independent timers are available in the breaker fail logic. The timers can be
programmed to act as a control timer or delay timer.
Programmable Timer Logic
A one to three shot recloser function is available with separate timers for reset, reclose fail, and maximum
cycle time.
Programmable Recloser Logic
Microprocessor software provides the capability of a programmable logic controller (PLC) to control the
outputs. Output control equations take the form of simple Boolean equations. Contact inputs (Ix), fault
detectors (Fx), timer outputs (Tx), and outputs relays (Ox) act as variables in the equations. The micro-
processor based programmable logic is covered in detail in Section 5, BESTlogic Programmable Logic.
Microprocessor Based Programmable Logic
Outputs
There are five types of BE1-BPR outputs:
• Alarm relay
• Output relays
• Targets
• Liquid crystal display (LCD)
• Serial ports RS-232/RS-485
Output relay OA is operated (energized) by the programmable logic section when logic equation LOA is
false. Table 4-1 lists the two LOA states and the corresponding hardware states.
Alarm Relay
Table 4-1. Alarm States
Logic Equation
LOA
HMI Alarm
LED
Alarm Relay
OA
Alarm
Contacts
0 Off Energized Open
1 On De-Energized Closes
The normally-closed configuration of output relay OA holds the Alarm output contacts in the open state
when LOA=FALSE (coil energized) and closes the contacts when LOA=TRUE (coil de-energized). If the
power supply voltage decreases below a predetermined level or the microprocessor watchdog times out,
the output contacts close (coil de-energizes). The software Alarm output (OA) is logically ORed with the
hardware logic power sensor and watchdog timer. Either input can trigger the Alarm output independently
from the software logic. The microprocessor-based relay logic cannot disable this hardware protection.