Schweitzer Engineering Laboratories SEL-749M - Table 10.1 Resultant Scale Factors for Inputs; Figure 10.1 Low-Level Test Interface (J2 and J4)

10.2
SEL-749M Relay Instruction Manual Date Code 20080918
Testing and Troubleshooting
Testing Tools
Use the TARGET command to view the state of relay control inputs, relay
outputs, and relay elements individually during a test. The TARGET
command is available at the serial ports and the front panel. See Section 7:
Communications and Section 8: Front-Panel Operations.
Low-Level Test
Interface
The SEL-749M has a low-level test interface on the current and voltage input
printed circuit boards. You can test the relay in either of two ways:
conventionally, by applying ac signals to the relay inputs or by applying low
magnitude ac voltage signals to the test interface on the printed circuit boards.
SEL-RTS Low-Level Relay Test System can be used to provide the signals to
test the relay. Figure 10.1 shows the Test Interface connectors. Table 10.1
shows the resultant signal scale factor information for the calibrated inputs.
The SEL-5401 program uses these scale factors.
Figure 10.1 Low-Level Test Interface (J2 and J4)
Access the low-level test interface connectors by using the following
procedure.
The relay contains devices sensitive
to Electrostatic Discharge (ESD).
When working on the relay with the
front panel removed, work surfaces
and personnel must be properly
grounded or equipment damage may
result.
!
CAUTION
Step 1. Loosen eight (8) mounting (and one ground) screws on the
back and remove the back cover.
Step 2. Remove the CT board from Slot Z.
Step 3. Locate jumpers JMP1–JMP4 and change them from Pin 1–2
(Normal position) to Pin 2–3 (Low-Level Test position).
Step 4. Locate connector J2 and connect low-level signal connector
(e.g., ribbon cable connector of SEL-RTS Test System).
Step 5. Insert the CT board back in its Slot Z.
Step 6. Remove the voltage board from Slot E.
Table 10.1 Resultant Scale Factors for Inputs
Channel
Label
Circuit Board
& Connector
SEL-5401
Channel No.
Nominal
Input
Output
Scale Factor
(A/V or V/V)
IA CT Board / J2 1 1 A 28.78 mV 34.7
IB CT Board / J2 2 1 A 28.78 mV 34.7
IC CT Board / J2 3 1 A 28.78 mV 34.7
IN CT Board / J2 4 1 A 274.7 mV 3.64
IA CT Board / J2 1 5 A 28.78 mV 173.7
IB CT Board / J2 2 5 A 28.78 mV 173.7
IC CT Board / J2 3 5 A 28.78 mV 173.7
IN CT Board / J2 4 5 A 274.7 mV 18.2
VA Voltage / J4 7 250 V 698.1 mV 358.1
VB Voltage / J4 8 250 V 698.1 mV 358.1
VC Voltage / J4 9 250 V 698.1 mV 358.1
NOTE: The SEL-RTS Relay Test
System consists of the SEL-AMS
Adaptive Multichannel Source and
SEL-5401 Test System Software.
(A) Connector J2 on Current Input Board (B) Connector J4 on Voltage Input Board
VAVBVC
GNDGNDGNDGNDGNDGND
1
IA
IBIC
IN
GNDGNDGNDGNDGNDGND
1
Courtesy of NationalSwitchgear.com