Basler BE1-CDS220, Instruction Manual

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BE1-CDS220 Testing And Maintenance 13-33
Step 3. Send to the relay the commands listed in Table 13-18.
Table 13-18. Setup Commands
Command Purpose
A= Gain access
For 5 A sensing input:
S#-TAP87=MANUAL,2.00,3.80 Set tap 1=2.00 and tap 2=3.80
For 1 A sensing input:
S#-TAP87=MANUAL,0.40,0.76 Set tap 1=0.40 and tap 2=0.76
You can test the relay either by increasing one current from a balanced condition or decreasing it. Refer to
the descriptions of both methods and Sidebar 13-3 to evaluate the differences in the two approaches.
Sidebar 13-3. Maximum Restraint Operating Characteristic
Under maximum restraint, the relay reaches the trip or operate point depending on the level of restraint
as shown in the associated figure. When only one current is changed, the restraint current can vary
depending on the relative changes between currents. When one current is decreased from balance, the
maximum restraint has a vertical characteristic. When increasing one current relative to the other, it will
shift to the right with a sloping characteristic as it continues to increase toward the trip region of the
operate characteristic.
1 2 3 4 5
MAXIMUM RESTRAINT CURRENT (IN MULTIPLES OF TAP)
OPERAT
ING CURRENT
(IN MUL
T
IPL
ES OF
T
AP)
123
Slo
pe
minimum
pickup
increasing current
from balance
decreasing current
from balance
D2857-13.vsd
10-14-99
In order to test the restrained pickup function of the BE1-CDS relay, you may increase one of two
currents initially applied in balance, to create an operate imbalance. In this narrative, the input 1 current
will be the input to be deviated. A similar analysis can be made for deviating input 2 current.
By increasing input current I
1
from balance, I
1trip
is defined as
I
1trip
= I
1balance
/(1-(
100
slope
))in per unit Sidebar 13-3, Equation 1
with the minimum trip point established as
I
1trip min
= I
1balance
+ minpu in per unit Sidebar 13-3, Equation 2
where: minpu is the minimum pickup setting