Basler BE1-60, Instruction Manual

3-2 

BE1-60 Functional Description 

9170700990 Rev D 

LIMIT SETTING 

The limit setting is controlled by the ten-position, front-panel, Differential Limit Switch. The limit setting 
circuit establishes a reference voltage that represents the maximum permissible voltage difference. 

LIMIT COMPARATORS 

Reference voltage established by the limit setting circuit is compared to the output of each differential 
amplifier. When the limit is exceeded by the voltage difference, a limit comparator generates a trip 
command signal (V > limit setting). 

OUTPUTS 

Limit comparator outputs are ORed so that the appropriate output relay coil energizes during a fault 
condition. In a fault condition, the relay coil that energizes corresponds to the circuit that senses the lower 
of the two voltage levels.  

When the lower of the two voltages increases, the voltage difference decreases below the limit setting 
and the relay coil de-energizes after a fixed delay of 0.75 seconds. 

OUTPUT TEST PUSHBUTTONS 

Two momentary-action pushbuttons, accessible through the front panel, are provided on BE1-60 relays 
with a style number of X1X A1X XXCXX. The output test pushbuttons are useful for testing output relay 
operation and external control/protective system wiring. The pushbuttons are operated by inserting a thin, 
non-conducting rod through the appropriate front panel opening. The lower pushbutton energizes the 
Circuit 1 output relay(s) and the upper pushbutton energizes the Circuit 2 output relay(s).  

AUXILIARY OUTPUTS 

Two sets of optional, auxiliary outputs are available on the BE1-60 relay. One auxiliary output changes 
state when the Circuit 1 output relay energizes; the other auxiliary output changes state when the Circuit 
2 output relay energizes. Auxiliary outputs may be specified as normally-open (style X1X A1X XXX1X), 
normally-closed (style X1X A1X XXX2X), or single-pole, double-throw (SPDT) (style X1X A1X XXX3X). 

POWER SUPPLY 

Operating power for the relay circuitry is supplied by a wide range, electrically isolated, low-burden power 
supply. Power supply operating power is not polarity sensitive. The front panel power LED and power 
supply status output indicate when the power supply is operating. Power supply specifications are listed 
in Table 1-1. 

POWER SUPPLY STATUS OUTPUT 

When the relay power supply is operating normally, the optional power supply status relay energizes and 
opens the normally-closed power supply status contacts. If the power supply output falls below the proper 
level or if operating power is removed from the relay, the power supply status relay de-energizes and the 
power supply status output contacts close. 

When the relay is equipped with a power supply status output (style X1X A1X X1XXX) and auxiliary 
outputs (style X1X A1X XXX1X, X1X A1X XXX2X, or X1X A1X SSS3X), the Circuit 2 auxiliary output 
contacts are dedicated as the power supply status output. The Circuit 1 auxiliary output contacts will 
operate when the Circuit 1 or Circuit 2 main output contacts operate. 

TARGET INDICATORS 

Target indicators are optional components selected when a relay is ordered. The electronically latched 
and reset targets consist of red LED indicators located on the relay front panel. A latched target is reset 
by operating the target reset switch on the front panel. If relay operating power is lost, any illuminated 
(latched) targets are extinguished. When relay operating power is restored, the previously latched targets 
are restored to their latched state. 

A relay can be equipped with either internally operated targets or current operated targets.