Basler BE1-CDS240, Instruction Manual

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You may also use the average restraint operating characteristic and test the relay by decreasing one
current from a balanced condition. For additional information on testing in this manner, see Sidebar 13-7.
Sidebar 13-7. Average Restraint when Decreasing One Input from Balance
A second way to test the restrained pickup of the BE1-CDS240 relay is to decrease one of two currents,
initially applied in balance to create an imbalance. In this narrative, Input 1 current will be the input to be
changed. A similar analysis can be made for changing Input 2 current.
By decreasing the input current I
1
from balance, the value of I
1trip
is defined as:
I
1trip
= I
2balance
(1- ((2*
100
slope
)/(2+
100
slope
))) in per unit
with the minimum trip point established as:
I
1trip min
= I
2balance
– minpu in per unit
where: minpu is the minimum pickup setting
Under test and in-service conditions, the following equations determine whether the relay operates along
the flat minimum pickup or slope of the operating characteristic. If
I
restraint at balance
> minpu x







2 / 1
100 /
1
slope
in per unit, use the 1
st
equation, or if
I
restraint at balance
< minpu x







2 / 1
100 /
1
slope
in per unit, use the 2
nd
equation.
Step 13: Send the commands listed in Table 13-28 to the relay.
Table 13-28. Setup Commands
Command Purpose
A= Gain access
S#-
87=0.35,15,0,0,0,1 Minpu = 0.35, slope = 15% (of average restraint), 2
nd
= disabled, 5
th
= disabled,
URO= disabled, 2
nd
harmonic sharing =1 (yes)
E Exit
Y Save
settings
Step 14: Apply balancing current to phase A Input 1 and phase A Input 2 at the magnitude indicated in
each row of either Table 13-29 (5 ampere sensing) or 13-25 (1 ampere sensing) and slowly
increase phase A Input 1 until OUT1 closes. Reference the corresponding table to verify
pickup accuracy.
13-44 BE1-CDS240 Testing and Maintenance 9365200990 Rev F