Basler BE1-24, Instruction Manual

BE1-24 Functional Description

3-5

As the timed trip pickup level is exceeded, the LEDs begin illuminating in ascending order from left to right
(green to red).  When all LEDs are illuminated, the timed trip output relay is energized.

Similarly (but in reverse order), as the volts per hertz condition falls below pickup, the LEDs extinguish in a
descending order (red to green).  The last step in the descending direction is reset.  At that time, the timed
trip output relay is de-energized.

WATCHDOG CIRCUITRY

The watchdog circuitry continuously monitors the operation of the microprocessor.  Should the
microprocessor malfunction or experience improper sequencing, the watchdog disables the microprocessor
and the normally closed (NC) relay fail output contacts close.  At this time, further operation of the relay is
inhibited.  The relay must be powered down, then powered back up, to re-initiate the microprocessor.

RELAY FAIL FUNCTION

A normally closed output contact is provided to indicate failure of the power supply or improper operation of
the microprocessor.  Under normal operating conditions, and with power applied to the relay, this output relay
is energized and its contacts are open.  If the power supply ceases to provide proper voltages to the internal
circuitry, or the watchdog circuitry detects a malfunction of the microprocessor, these contacts close.

TARGETS

Magnetically latching, manually reset target indicators are optionally available to indicate that a timed trip
output or an instantaneous trip output (if selected) has closed.  For details refer to Section 1.

BUILT-IN-TEST

Built-in-test (BIT) is a feature (not shown on block diagram) that provides a  quick-test routine that is
programmed into the relay.  When initiated by the printed circuit mounted slide switch on the logic board, the
relay performs a pre-programmed sequence that verifies all indicators and outputs.  Each event of the
sequence occurs at one-second intervals.  BIT provides a quick hardware check prior to installation or
troubleshooting.

PUSH-TO-ENERGIZE-OUTPUT PUSHBUTTONS

Push-To-Energize-Output pushbuttons are optionally available to energize each output relay for testing the
external control/protective system wiring.  The pushbuttons are actuated through front panel access holes
by means of a thin non-conducting rod having a maximum diameter of 0.125 inches.

POWER SUPPLY

Basler Electric enhanced the power supply design for unit case relays.  This new design created three, wide
range power supplies that replace the five previous power supplies.  Style number identifiers for these power
supplies have not been changed so that customers may order the same style numbers that they ordered
previously.  The first newly designed power supplies were installed in unit case relays with EIA date codes
9638 (third week of September 1996).  Relays with a serial number that consists of one alpha character
followed by eight numerical characters also have the new wide range power supplies.  A benefit of this new
design increases the power supply operating ranges such that the 48/125 volt selector is no longer
necessary.  Specific voltage ranges for the three new power supplies and a cross reference to the style
number identifiers are shown in the following table.