Basler BE1-CDS220, Instruction Manual, Page: 346 / 476

13-32 Testing And Maintenance BE1-CDS220
Table 13-17. Commands To Prepare For Pickup Testing
Command Purpose
A= Gain access
SL-N=NONE Zero out custom logic settings/overwrite with
logic = none settings
Y Confirm overwrite
SL-N=RDIFF Name custom logic for this test
SL-87=1,0 Enables 87
SL-VO1=87RT Enables OUT1 to close for 87 restrained trip
SG-CT1=1,WYE,NA ctr=1, ct=wye, xfmr=na
SG-CT2=1,WYE,NA ctr=1, ct=wye, xfmr=na
SG-TRIGGER=87RT,
7RPU,0 Enable 87RT to log and trigger fault recording
E Exit
Y Save settings
circuit
monitor
current
source 1
180 degrees
current
source 2
B1 B3 B5 B7
B2 B4 B6 B8
B9 B11 B13 B15
B10 B12 B14 B16
I
A1
I
B1
I
C1
I
G
I
A2
I
B2
I
C2
I
A1
I
B1
I
C1
I
G
I
A2
I
B2
I
C2
Figure 13-13. Connections for Restraint Verification
Sidebar 13-2. Percentage Differential Restraint Operating Principle
The percentage differential restraint characteristic of the BE1-CDS relay is illustrated in Section 1, Figure
1-1. The knee of the operating curve for any slope setting is determined by taking the minimum pickup
operating characteristic and dividing it by the slope.
For example, for a minimum pickup setting of 0.30 and a slope setting of 15%, the knee of the operating
curve is plotted at a point equal to 0.30/0.15=2.00 multiples of tap on the maximum restraint current axis.
This implies that at these settings, the relay requires greater than 2.00 multiples of tap of maximum or
average restraint current to operate along the 15% slope characteristic of the relay.
Thus, for restraint currents less than the knee of the curve, the relay will operate at a differential current
greater than or equal to the minimum pickup operate setting. Beyond the knee of the curve, the differential
current operating characteristic is defined along the slope portion of the curve.
The BE1-CDS relay has two distinct operating principles for performing the restraint operation. Maximum
restraint uses the maximum of the two compensated currents as the restraint while average restraint, uses
the average of the two compensated currents. Either characteristic may be selected via the S<g>-87
command. For more information on the S<g>-87 command, refer to Section 4, Protection and Control
Functions, Differential Protection.