TYPE CN-33P RELAY
weights and adjust.
The inner spring support
should not touch the spiral spring adjuster.
D.
Adjust the stationary contact screws to deflect
the moving contact when the drum is against its
stop, to a point where they just fail to touch
their supporting bracket.
Set the spiral spring
so that the TRIP contacts just make.
Electrical
The relay should be preheated before calibration
by applying rated volts, either single phase or three
phase to the potential coils for a period of 1 hour.
The relay can then be calibrated using the test
circuit of Fig. 9.
T{ipping Adjustment
With the TRIP contacts set to just make, the
current
and phasing
(outer) electromagnets are
adjusted, single phase to give the desired voltage
only bias in the close direction by the following
procedure.
1. Apply rated voltage to phase A potential coil
(Switch A).
Energize the current coils with 6
milliamp (Sw A" and Sw A
1,
pos. 1).
Adjust
phase A phasing and current (outer) electromagnet
by varying the air gap between it and potential
(inner) electromagnet. The TRIP contacts should
just make at 6 milliamps and break at 5 milliamps
or above.
Adjust phase B and C similar to phase A.
2. With all phases calibrated the three phase triP
should be checked. Apply rated three phase volt
age (Switches ABC) and adjust the current until
the trip contacts just make and the three currents
are equal.
The TRIP contacts should make at
2.0 to 2.4 milliamp three phase.
If the trip cur
rent is not within this range, the following re
adjustments should be made.
a)
If
the
trip current is high
change the spiral
spring setting by turning the pinion one to
two teeth in a direction to open the trip
contacts, then readjust the outer electromag
nets. Recheck the three phase trip value.
b) If the
trip current is
low,
change the spiral
spring setting by turning the pinion one to
two teeth in a direction to close the trip con
tacts, then readjust the outer electromagnets.
Recheck the three phase trip value.
3. With zero current applied to the relay, increase
the voltage from zero. The TRIP contacts should
open at 100 volts or less.
With rated voltage applied to the potential coils
and 0.5-2.0 volts on the phasing coils (Switches
A' B' C'-Pos. 2; 2 amps through 1 ohm non-inductive
resistors) adjust the CLOSE contact to make by
using the phasing voltage adjusting screw. Normally
the final setting will be made at 0.5 to 0.
7
volts.
With the above calibration the relay should have
the characteristics shown in Figures 5, 6,
7
and 8.
NOTE:
Remove relay from case and check to see that
m1mmum
clearance
between
any
outer
electromagnet and the drum is not less than
.015" when the relay is in its normal oper
ating position.
The permanent magnet gap should be ap
proximately .020 inches.
BURDE N
Potential Coils@ 125 volts, 60 cycles: 24.5VA
phase
@ 80° lag
Current Coils @ 5 amperes, 60 cycles: 9.4VA/phase
@
62° lag
Phasing coils @ 125 volts, 60 cycles:
phase
angle-
VA
�
ohms
Bkr. open, Phases A&C
6.5
22°
1200
Bkr. open, Phase B
0.91
40
12000
Bkr. closed, Phases A,B &C
3.9
13°
3100
11
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