Westinghouse KC-4, Инструкция по установке, эксплуатации и обслуживанию

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0 Acceptance Test
The following check is recommended to insure
that the relay is in proper working order. R efer to
Fig. 10 for test connections.
Overcurrent Detec:tor
Check for correct scale marking by placing all
the tap settings in the 0.5 Amp. position and rotate
the Phase and Ground tap multiplier knob (on the
overcurrent unit knob) to the
X I
calibration mark.
J umper test point TP 6 and TP7 on the timer
module and apply rated de voltage. Also apply
phase current to phase A input. The voltage at test
point TP3 on the overcurrent module should drop
from approximately 23.5 volts to less than 2 . 5 Vdc
when the ac current input is between .48 and .52
amperes. The AR output relay will pickup at the
0
same time. When TP6 and TP7 is jumpered the
dropout time of th1:! ojc output at TP3 will be
slow. Opening switch to terminal 9 momentarily
will speed up the dropout time.
Use the same tt:st with applying current to
phase C (and also phase B if used). Pickup should
be within 5% of the phase A pickup.
Rotate Tap M ultiplier Knob to the X3 setting
and repeat above. The operate current should be
between 1 .44 and 1 . 56 amperes on phase A input
and within 5% of phase A pickup for phase C (and
phase
B if
used) .
For setting Phase A current operate level, set
the tap screw in the proper range location and set
the phase tap multiplier at the point at which the
voltage at TP3 changes from high to low at the
desired input current. The phase C and Phase B (if
used) tap screws should be set for the same current
0
range. The AR output relay will also pickup and
can be used for an indication.
The Ground overcurrent setting is checked and
set exactly like the phase overcurrent circuit.
A locking feature: is provided to hold the tap
multiplier knob at the desired setting.
Control Timer
U se a low bounce initiate contact in series with
relay terminal 9 (positive). Connect an electronic
6
timer to the relay so that the start input is con­
nected to relay terminal 9 (through a voltage
divider, if necesary). The stop input should be con­
nected to the bottom test jack on the timer
module. The common should be connected to ter­
minal 8. The test timer start input should be ad­
justed to commence timing on a positive going
slope and to stop timing on a negative going slope.
The control timer output should go from a high
state to a low state in 1 90 to 2 1 0 milliseconds (or
0
in 570 to 630 ms for the longer range timer).
If some other time interval is desired, the timer
setting may be changed by means of a screw driver
adjustment through the access hole on the timer
module to a multiturn potentiometer. Use the elec­
tronic test timer in the manner described to obtain
the desired time interval . Remember that the Con­
trol Timer should always be set at least 1 6 milli­
seconds longer than the BF timer. The adj ustment
0
range is 1 50 to 250 ms (or 1 50 to 600 ms in the
longer range timer).
BREAKER FAI LURE ( B F)
T I M E R
This may b e checked i n the same way a s tht:
Control Timer.
First jumper test points TP6 and TP7 on the
timer module. Connect the test timer stop lead to
the upper test j ack on the timer module. Output of
the B F timer takes place when it goes from a high
state to low state (similar to the Control Timer
0
output). Close switch to terminal 9 and see that tht:
timer output switches in 1 70 to 1 80 ms (or 485 to
5 1 5 ms for the longer range timer) .
Set the timer knob at the desired setting and
verify setting by operating the timer several times.
The timer should operate within 5% of the setting.
The setting may be made closer by means of the
electronic test timer.
When the desired setting has been obtained it
may be locked in place by means of the locking
tab.
Overall operation may be checked by connec­
ting rated de voltage to relay terminal 1 8 (52A
breaker auxiliary contact input).
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