Table of Contents
Advertisement
0
Acceptance Test
The following check is recom mended to insure
that the relay is i n proper working order. Refer to
Fig. 1 0 for test connections.
Overcurrent Detector
Check for correct scale m arking 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 k nob) to the X 1 calibration mark .
Jumper test point TP 6 and TP7 on the timer
m odule 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
fro m approximately 2 3 . 5 volts to less than 2 . 5 Vdc
when the ac current input is between .48 and . 5 2
amperes. The A R output relay will pickup at the
same time. When TP6 and TP7 is jumpered the
0
d ropout time of the ojc output at TP3 will be
slow. Opening switch to terminal 9 momentarily
will speed up the dropout time.
Use the same test with applying current to
phase C (and also phase B if used). Pickup should
b e within 5% o f the phase A pickup.
Rotate Tap M u ltiplier Knob to the X3 setting
and repeat above. The operate current should be
between 1 .44 and 1 . 56 a mperes 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 l ocation and set
the phase tap m u ltiplier 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
u sed) t a p screws should be set for t h e same current
range. The A R output relay will also picku p and
0
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 h old the tap
m ultiplier 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 m illiseconds (or
0
in 570 to 630 m s 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 h ole on the timer
m odule to a multiturn potentiometer. Use the elec-
tronic test timer in t h e m anner 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 adjustment
0
range is 1 50 to 250 m s (or 1 50 to 600 m s in the
longer range timer).
B REAKER FAI LURE ( B F)
This may be checked in the same way as the
Control Timer.
First jumper test points TP6 and TP7 on the
timer m odule. Connect the test timer stop lead to
the upper test j ack on the timer module. Output of
the BF timer takes place when it goes from a h igh
state to low state (similar to the Control Timer
output). Close switch to terminal 9 and see that the
0
timer output switches in 1 70 to 1 80 m s (or 4 8 5 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 l ocking
tab.
Overall operation may be checked by connec-
ting rated de voltage to relay terminal 1 8 (52A
breaker auxiliary contact input).
TI M E R
":•••"i:f , .
Advertisement
Table of Contents
