BECKWITH ELECTRIC Syncrocloser M-3410A, Instruction Book

Page: 176 / 225

5–15
Testing – 5
40 Loss-of-Field (#1 or #2)
VOLTAGE INPUTS : Configuration V1
CURRENT INPUTS : Configuration C1
TEST SETTINGS :
Diameter P PU (0.01 to 3.00)
Offset O PU (–2.00 to 2.00)
Time Delay D cycles (1 to 8160)
Voltage Control %* (4 to 100)*
(* of Nominal Voltage)
Programmed Outputs Z OUT (1 or 2)
Functions 27, 32, 60FL, 79 Disable
Function 40 Volt Control Disable
Function 40 (#1 or #2) Disable
VT Configuration Line-Ground
Q Q Q Q Q
NOTE : It would be efficient to disable the function with the higher “reach” (diameter minus offset)
setting first (lower current) and test the lower “reach” setting operation. Since the higher setting
operation can be tested without disabling the lower setting, the 40 functions will be enabled
when the tests are complete.
1. Disable functions as shown. See Section 3.2, Setpoints and Time Settings, for procedure.
2. Confirm settings to be tested.
3. Connect inputs in Configuration V1 and C1 designated above. See Section 5.1, Equipment/Test
Setup for configurations.
4. The level of current at which operation is to be expected for an individual setting is as follows:
a. Define “reach” as R
PU
= (P
PU
– O
PU
) where O
PU
is essentially negative.
R
sec
= R
PU
( ), O
sec
= O
PU
( )
V
N
*
I
N
V
N
*
I
N
*for L-L and L-G-to-L-L VT configuration, use V
N
/
S
3
b. Define “trip current” as
I
= (Applied Voltage ÷ R
sec
) . The voltage level may be selected
based on the desired test current level.
c. Define “offset current” as
I
O = (Applied Voltage ÷ O
sec
).
5. Set the three-phase voltages V
A
, V
B
, and V
C
to the Applied Voltage value from step 4, and
set the phase angle between the voltage and current inputs to 90° (current leading voltage).
6. Pickup Test : Press and hold the TARGET/OUTPUT RESET pushbutton and slowly increase
the three-phase currents until the appropriate LOSS OF FIELD 40 LED light illuminates or the
pickup indicator operates on the Function Status screen. The level will be equal to “ I ” calculated
in step 4 with the resulting impedance within & 0.01 PU or & 5%. If the offset is negative,
continue to increase the current until the LED extinguishes. The level will be equal to “ IO ”
calculated in step 4 with the resulting offset impedance within ±0.01 PU or ±5%.
7. Release TARGET/OUTPUT RESET pushbutton and decrease the currents. Press TARGET/
OUTPUT RESET pushbutton to reset targets.