4. Disconnect the 18-pin male connector end of the tester
interrupter interface cable (Item 1) from the 18-pin
female end of the VFI control wire harness (Item 3).
NOTICE
Equipment misoperation. The capacitors upon the Tri-
Phase and TPG boards will retain a charge of 20 Vdc
upon completion of control testing. Apply a 5 k ohm
resister between ground and the P1-7, P1-5, and P1-3
board terminals for 10 seconds prior to returning the
control to service. Failure to comply can result in false
tripping activity by the control upon reinstallation.
T318.0
5. Reconnect the VFI control wire harness (Item 3) to the
18-pin male receptacle located upon the Tri-Phase/TPG
control.
6. Disconnect the interrupter and control interface cables
(Items 1 and 2) from the VFI tester and store the
cables in the storage compartment located in the cover
of the VFI tester.
7. Close
the
VFI
switches.
Control tests
The VFI tester enables testing and verification of minimum
trip timing values for each phase of the VFI unit. Testing at
nominal test current values of 150, 300 and 1000 percent
of minimum trip current levels verifies Tri-Phase/TPG board
response at current levels typically requiring slow, medium
and fast trip operations.
Test current values are set by selectively closing a group of
toggle switches controlling a stepped network of resistors
within the VFI tester unit (Figure 5). Placing the 4-30 A
toggle switch into the ON position enables operation of a
4-30 A fine adjustment rheostat for precise adjustment of
test current levels.
Pressing the Control Test button of the VFI tester initiates
injection of simulated fault current into the Tri-Phase/TPG
control board and concurrently begins measurement of the
accrued time between test initialization and and issuance
of a trip signal. Upon issuance of a trip signal, the flux-shift
tripper of the respective phase being tested should operate
as the LCD display indicates the accrued trip-time interval.
ote:
N
Once a control test is initiated, pressing and releas-
ing the control test button a second time will result
in the test being aborted.
Battery tests can not be conducted during a control test.
Initial tester setup
Refer to Figure 2 for identification of individual VFI tester
switches and other features referenced within the following
setup procedures.
1.
Connect the VFI tester to the VFI Padmount unit
following the procedures described in the
Testing
In-Service VFI Units
section of this service bulletin.
2. Connect external multi-meter to the multi-meter tester
connection jacks and set external meter to appropriate
current measurement range.
3. Energize the tester by setting the power switch to ON.
Conduct internal flux-shift tripper test
The internal VFI tester flux-shift trippers should be tested
for correct operation at the beginning of every control
testing session. Failure to verify the correct operation of the
internal flux-shift trippers prior to a control test could result
in an erroneous assessment of control performance, in the
event of a malfunction of the internal VFI tester flux-shift
trippers.
Verify the internal flux-shift trippers are operational with the
following procedure:
1.
Depress all three internal flux-shift trippers. Refer to
Figure 3 for steps 1 through 8.
2. Place the Test Selector Switch into the INTERNAL
TRIPPERS position.
3. Place the Phase Selector Switch into the A-PHASE
position.
4. Press and release the Tripper Test button. The A-Phase
flux-shift tripper on the VFI tester should operate
immediately.
5. Place the Phase Selector Switch into the B-PHASE
position.
6. Press and release the Tripper Test button to initiate the
test. The B-Phase flux-shift tripper on the VFI tester
should operate immediately.
7.
Place the Phase Selector Switch into the C-PHASE
position.
TEST
CONTROL
4-30A
30A
60A
120A
240A
1X
4-30A
2X
ON
ON
ON
ON
ON
1X/2X Current
Multiplier Switch
Current
Adder
Switches
4-30A Rheostat
Enable Switch
4-30A Rheostat
Figure 5. VFI tester current adjustment switches.
Operating Instructions
MN285001EN December 2018
7
