Basler BE1-79A, Instruction Manual

A-2 

BE1-79A RS Contact Application 

9310200990 Rev G 

operating power is not applied to terminals 5 and 6 and the mode selected is D (de-energized), then the 
RS contact function, as selected by S5 (NC or NO), is just as if you were measuring contact continuity 
across terminals 9 and 10 with the relay sitting on a test bench with no wiring connected. If the mode is E 
(energized), then operating power must be present at terminals 5 and 6 to hold the RS contact in its 
desired position at the BE1-79A’s reset position. 

RS CONTACT SETTINGS 

The RS contact setting command, SP-79ARS, determines the mode, apply time, and remove time of the 
RS contact. SP-79ARS command syntax is SP-79ARS[=<mode>,<apply time>,<remove time>]. 

The mode setting indicates the state of the RS element when: 

•

The relay has operating power applied to terminals 5 and 6 

•

The BE1-79A relay is in Reset while the RS contact Remove time expired 

A mode setting of D will de-energize the RS element during the conditions indicated above. A mode 
setting of E will energize the RS element for the conditions indicated above. An Apply time set at zero is 
applied as soon as the circuit breaker 52b contact makes. An Apply time set at a value other than zero 
begins its timing sequence as soon as the breaker opens on its first trip and the 52b contact makes. 
Remove time also begins when the 52b contact makes for the first time in a reclose sequence and lasts 
until its programmed Remove time is reached or the breaker successfully recloses and the BE1-79A 
returns to Reset. 

Examples of four different RS contact configurations and settings are shown in Figure A-1 and explained 
in the following paragraphs. 

Mode D Example 

From Table A-1, for mode D settings, an NC RS contact (S5 = NC, mode = D) will be closed during BE1-
79A power-off and will remain closed when the BE1-79A relay is powered on. (This assumes that the 
Remove time from a previous reclose cycle has expired or the relay is in Reset.) The NC contact will 
remain closed until a reclose cycle begins and the RS contact Apply time is reached. The NC contact will 
then open and remain open until the RS contact Remove time is reached. (If operating power is lost at 
terminals 5 and 6 during this time, the NC contact will close as indicated in Table A-1, BE1-79A Power 
Off). 

When the Remove time expires, the NC contact will again close and remain closed until a new reclose 
cycle is started. For SP-79ARS=D,0,145, as soon as the circuit breaker 52b contact makes following the 
first trip, the RS contact will open and remain open until a time of 145 seconds where it will open and 
remain open until a time of 145 seconds where it will again close. For SP-79ARS=D,2.5,145, the RS 
contact will remain closed for 2.5 seconds after the circuit breaker 52b contact closes for the first trip-out 
and then be open until the 145 second time is reached or reset occurs. If the BE1-79A goes to reset 
before the Remove time is reached, the RS contact changes back to its state at reset without having to 
time to the Remove time setpoint. 

From Table A-1, for mode D settings, an NO RS contact (S5 = NO, mode = D) will be open during BE1-
79A power-off and will remain open when the BE1-79A is powered on. (This assumes the Remove time 
from a previous reclose cycle has expired or the relay is in Reset.) The NO contact will remain open until 
the reclose cycle begins. At that time, the NO contact will continue to remain open until the RS contact 
Apply time is reached. The NO contact will then close and remain closed until the RS contact Remove 
time is reached. (If relay power is lost during this time, the NO contact will open.) When the Remove time 
expires or the BE1-79A resets, the NO contact will again open and remain open until the next reclose 
cycle. 

Mode E Example 

From Table A-1, for mode E settings, an NC RS contact (S5 = NC, mode = E) will be closed during BE1-
79A power-off and will be energized and opened when the BE1-79A is powered on and in Reset. The NC 
contact will remain open until the reclose cycle begins. At that time, the NC contact will continue to remain 
open until the RS Apply time is reached. The NC contact will then close and remain closed until the RS 
contact Remove time is reached. (If relay power is lost during this time, the NC contact will remain 
closed.). 

When the Remove time is reached or the BE1-79A resets, the NC contact will again open and remain 
open until the next reclose cycle begins from the Reset position.