Westinghouse KC-4, Installation, Operation & Maintenance Instructions Manual

Page: 120 / 178

TY P E SB F U STATI C CI R C U I T B R EA K E R FAILU R E R E LA Y
Range
. 5-2
1-4
2-8
4- 16
T A B L E I I
C U R R E N T R A T I N G S
Continuou s O ne Second
8 Amp s. 350 Amps .
1 0 Amps. 400 Amps.
1 2 Amps. 400 Amp s.
15 Amp s. 400 Amps.
S E TT I N G
The only setting required is the overcurrent
unit and t imer unit. These are set for each over­
current unit by means of the knob adjustment located
on the front of each overcurrent unit module . Like­
wise, the timer setting is made by means o f the front
knob on t he timer module .
I N S T A L L A T I O N
0
The relays should be mounted on switchboard
panels or their equivalent in a location free from dirt,
moisture, excessive vibration and heat. The maxim u m
ambient temperature around the chassis m u st not
exceed 55" C. Mount the rela�· by means of the fou r
slotted holes on the front of t h e case. Additional support
should
be
provided toward the rear of the relay in addition
to the front panel moun ti ng. This will protect against
warping of the front panel due to the extended weight
within the relay case. Ground relay chassis with No. 12
A W G copper wire to grounding post.
6
A D J U S T M E N T S A N D M A I N T E N A N C E
The proper adjustments to insure correct op eration
of thi s relay have been made at the factory and
should not be disturbed.
Acceptan ce Test
Th e follo wing check is recommended to insure
that the relay is in proper working order. R efer to
the logic drawing pertaining to the p articul ar relay
( Dwg. No. is located on the relay namepl ate) for
correct terminal connection s . The test drawing shown
in Fig. 43 may be used.
Overcu rrent U n i t
Check for correct scale marking b y applying
current with the knob set
at
either end of the scal e .
A voltage o f approximately 2 0 V. d. c . should appear
at the test terminals (lo cated at the front of the
overcurrent unit module) when applied a-c current
i s within
±
lOo/c of the seal e setting.
Check the dropout ratio (94 to 98o/c of pickup
current) by reducing the applied a-c current until the
voltage at the test points falls to zero .
Ti mer U n i t
A timing check a t t h e minimum and m aximum
settings i s recommended to insure that the timer
module i s in proper working order. Thi s can be done
at the same time an overall test o f the relay i s
made.
Overa l l Test
Refer to the logic drawing and test drawing.
Connect an 86 device between strip terminal 4 and
ne gative. Connect 125 volts d-e positive to terminal
3 of the terminal strip. Connect rated voltage to
to terminal J6 and JS of the Varicon connector
through normally open switches . For some logic
drawings also connect rated voltage to J 1 5 , J 1 6 and
J 1 7 . Connect negative of supply to J3 . Also connect
positive control voltage to terminal J4 and negative
control volt age to terminal J3 .
Using a module extender ( S#849A534GO 1 , or
3494A90GO 1) remove the timer module and insert the
module extender into the timer slot position in the
relay. Now plug in the timer module into the modul e
extender. This makes the timer board terminals
accessible. Connect an electronic test timer so
that a positive signal at terminal
2
of the timer
module will stop the test timer. By using a DPST
switch in serie s with the input to terminal J6 then
the test timer can be started at the same time J6 is
energized. On some relays the timer module output
is connected to the relay output so that the modul e
extender is not required.
With overcurrent unit set
at
minimum , apply
twic e pickup current , and the timer module set at
0 . 2 seconds, check to see that an output appears
at terminal 2 of the timer board 0. 2
±
. 0 1 seconds
after the switch to terminal J6 i s closed. The light
connected to the trip terminal should go on at the
same time. Open switch to J6 and reset the light.
When a seal-in feature is supplied it will be neces­
sary to reset the overcurrent unit.
The same procedure should be repeated using
IA and then
lc
input. Check also to see that an
output is obtained when J8 switch is closed with
an overcurrent unit input above pickup applied .
If there are other inputs such as J 1 5 and J 16
check to see that an output is obtained when either
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