56
New generation IZM97, 99 low voltage air circuit breaker instruction manual
MN013010EN February 2020 www.eaton.com.cn
Section 4: Accessory devices
“A”
B
D
“B”
B
D
“C”
B
D
“D”
B
D
Gap
=1mm
Gap
>1mm
Gap
<1mm
Gap 0
Gap 0
Figure 10. Step 10
Step 10: This step describes how to adjust the cables. Refer to
Figure 10 on Page 5. Cable adjustment is controlled by spacer
nut installed at the side of cable support bracket. The small nut is
installed at the bottom of the long rod and should not be removed
after installed. Initial adjustment must be performed with the circuit
breaker OPEN. Install the spacer nut on the center of thread por-
tion of the long rod, then hand tighten it for later adjustment.
Figure 10 “A” describes that the trip bar controls the opening of
two connected circuit breakers. The swivel ring on the control
lever is controlled by a return spring to attach down to one or two
nuts on the lower drive lever. Adjust the large spacer nut of the
right (D-position) rod back and forth until the lower nut fits on the
swivel ring and rises slightly relative to the support panel. A gap
can be seen between the upper washer and the support panel
slot. At this point, there is also a gap of a few millimeters between
the lower nut and the swivel ring on the left (B-position). Operate
the B-position long rod to close the circuit breaker. Move the left
rod down until the control nut is close to the swivel ring (Figure
10 “B”). The support panel can be moved vertically and cannot be
rotated. Adjust the spacer nut on the B-position cable housing to
make the left cable rod up and down until the gap between the
upper rod nut and the swivel ring is less than 1mm. If necessary,
adjust other cable ends (C-position of other circuit breakers).
Disconnect the circuit breaker.
Operate the D-position long rod to close the circuit breaker. The
support panel should be placed upright and cannot be rotated
(Figure 10 “C”). The two interlocked circuit breakers are now open.
Move the left control rod down and right control rod up, and rotate
the support panel by about 60 degrees counterclockwise. Check
the final position of the inner shaft (this will move the cables and
trip the circuit breaker). Rotate the support panel clockwise to pass
through the vertical position, keeping the cable close to the stroke
end. If the tripper bar is not attached to the end position, raise the
right cable and/or lower the left cable.
To open and close two interlocked circuit breakers at the same
time, make sure to return the support panel to the vertical position
each time. When one (single) of the interlocked circuit breakers
is closed, it is necessary to close the auxiliary circuit breaker.
When both breakers are closed, the interlock mechanism does not
respond to any closing attempts. After the function is confirmed,
the adjusted cable must be fastened using a nut. Torque to 10Nm.
Accurately adjust the other two circuit breakers in the same way.
Each adjustment is independent of other circuit breakers. After the
adjustment is completed, it can be seen that the six cables are
adjusted, functional testing performs normal, and the adjustment
nuts are tightly screwed. After all operations are completed, the
closing of any two breakers will prevent the third breaker from
being closed.
Step 11: Test the interlock mechanism in the last step as shown. To
test 6-line interlock mechanism:
1. Charge and close Breaker A and B. Breaker C should
be held in OPEN condition. Inspect the drive rod on
Breaker C. The drive rod should be seen rotated to the
end position (support bracket). Charge Breaker B and
C and attempt to close them. Both circuit breakers
should not respond to CLOSE attempt (no noise, spring
discharge or connection motion). If the circuit breakers
respond to the CLOSE attempt, refer to Step 3 to Step
11. Additional adjustments may be required at cable
mounting bracket
2. Open Breaker A. The interlock mechanism should be
released. Close Breaker C. Check whether the breaker
is in OPEN/CLOSED position displayed by the indicator.
Breaker A should now be held in the OPEN position.
Repeat the above on Breaker A (drive rod position
adjustment, attempt to close)
3. Open Breaker B. The interlock mechanism should be
released. Close Breaker C. Check whether the breaker
is in OPEN/CLOSED position displayed by the indicator.
Breaker A and B should now be held in the OPEN posi-
tion. Repeat the above on Breaker A and B (drive rod
position adjustment, attempt to close)
Utilize a light amount of lubricant grease on the interlock
parts to reduce friction if any parts are sticky.
Table 2. Step 11 principles
Six-cable interlock assembly
TR2
TR1
C
B
A
A
B
C
0
0
0
1
0
0
0
1
0
0
0
1
1
1
0
0
1
1
1
0
1