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Vacuum
circuit breaker is suitable for the circuit of AC 50Hz, rated voltage 1140V and
below this level, rated current 630A
and below this current level, as the total switch, branch switch of the power
supply system, and also can be used as the starting for large volume motor. It
is also suitable for a variety of distribution switches made up by various kinds
of protection devices, especially for the coal mine explosion-proof vacuum feed
switch.
一、Ambient condition
Altitude: no more than 2000m
Ambient tenperature:-25℃-+40℃
Relative Humidity: not exceed 95％ at +25℃
The inclination
of the mounting position and vertical is no more than 15°.
No gas and conductive dust damage the
insulation in the surrounding environment.
二、Basic model
Main circuit poles: three poles (NO)
Auxiliary contact: two NO, two NC
The circuit breaker is electromagnetic
closing, mechanical latching (when the
under voltage coil is energized).
Circuit breaker is
with shunt tripper,
under voltage tripper and manual opening.
三、
Structure and working principle
The circuit breaker is composed of three vacuum tubes,
installed in insulated bracket. There is over-travel spring at the moving
conductive rod end, which can increase the contact pressure and reduce the
contact bounce. The moving conductive rod is connected through the connector
screws, the arm and the closing electromagnetic system. There are the opening
spring and the maintaining hook installed on the armature plate, which can make
the circuit breaker mechanically latching in the closing condition. The other
end of the maintaining hook is fasten by the opening rotation axis, which is
mechanically controlled by the shunt coil, under voltage coil and
manual tripper, make the opening rotation axis rotate and trip to achieve the
purpose of opening.
The circuit breaker adopts two level tripping mechanism,
which can make the circuit breaker keep the closing condition at a minimum power
(under voltage coil energized), and it can also compose of various distribution
switch with various protection devices. Two level tripping make the control
power of the breaker power small, and the opening time short.
四、Acting procedure of the circuit breaker
1.Closing: receiving the closing instruction, the closing coil
is energized, electromagnet is excited and absorpt the armature. On the one
hand, compress the opening spring to storage energy; on the other hand, drive
the arm action to make the vacuum interrupter closing, at the same time the
maintaining hook turns, fasten by the opening rotation axis(at the condition of
the under voltage got electric pick-up) to achieve the mechanical latching,
converse with the external auxiliary contacts, after a group of contacts delayed
(delay 50ms to 100ms through the external circuit ), cut off the closing coil
power. The whole closing action is completed.
2.Opening: receiving the opening instruction, the shunt coil
are imposed rated control supply voltage, under voltage coil de-energizing (the
voltage drop to 35% and below of the rated control supply voltage) or by the
manual opening (these three can be activate simultaneously), at this time, the
opening rotation axis rotate to trip, the armature and the maintaining hook
rotate under the action of the opening spring, through the arm to make the
vacuum interrupter cut off the circuit, and at the same time, the auxiliary
switching conversion, the closing is completed.
六、Additional instruction
1.When the circuit breaker is breaking the inductive load, it
must be added RC protection or varistor protection to prevent over-voltage
operation.
2.When the circuit breaker is closing the circuit that has Yufu
short-circuit fault, it must be taken the measures of "jump"
preventing by the method of electric.( after close the short circuit and
automatic closing, even if the closing instruction has not been relieve, it will
not be re-closing), such as installing the "jump" preventing relay.
3.The electric
schematic of the control circuit: see picture 1.
Picture 1
七、Preparation before operation
1.For the outline and mounting dimension of the circuit
breaker, see picture 2. Pls read the instruction carefully before installation.
2. The circuit breaker must be checked and tested before put
into operation.
2.1 Checking if the connection part is loose, and make the
appropriate treatment.
2.2 Checking if the operating characteristics is reliable,
it must be operate and can not be mis-operate, the
auxiliary switch converts reliably,
which can be checked according to the third requirement.
2.3 If allowed the circuit breaker should do the following
required voltage test for 1 minute, no arcing or flashover phenomenon.
a. The voltage between the moving and
static contact of the vacuum interrupter is 10KV.
b. The voltage between phase and phase, phase and ground is
4.2KV.
3.When
installing the circuit breakers, the main conduction circuit should be connected
to the load of the power by a suitable conductor, the size of the conductor must
meet relative requirements.
After connection, it should ensure the vacuum interrupter
does not produce stress to avoid
damaging the vacuum interrupter or changing the distance between the moving
and static contact, affecting the contact resistance of the contact.
八、Maintenance and repair
The maintenance purpose is to keep the performance of
switching device, find the problem earlier to take
preventive measures. Generally the maintenance is divided into
regular maintenance and trouble hunting.
1. Regular maintenance (see table 1)
2. Trouble hunting (see table 2)
3. The circuit breaker will be out of operation when one of
the following status occurs during operation:
a. operation times
reach to the technical condition specified life.
b. after opening
and closing the short circuit current.
Table 1
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No.
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Inspection items
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The main inspection items
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cycle
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Note
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1
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opening and closing action
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opening and closing the circuit breaker
for many times, check if the stroke overtravel is normal
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one time/3 months
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2
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the general check of the outside conduction circuit
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checking the fastener of the main
conduction circuit
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one time/3 months
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3
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Operating mechanism
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checking the fastener of the control circuit, rotate the
friction part and add lubricant.
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one time/3 months
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4
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cleaning of each part
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each insulating parts, auxiliary switch and contact, etc. on
the surface of the vacuum interrupter
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one time/3 months
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5
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test items
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test the insulating resistance between
the main circuit contacts, main circuit and the control circuit to ground.
withstand voltage test between the
contacts of the main circuit.
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one time/year
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the insulating resistance of the main
circuit is 100MΩ,
the control circuit to ground is above 2MΩ, the withstand voltage between the main circuit
contacts is 10KV/1min, no arcing or flashover phenomenon.
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Table 2
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fault
status
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fault reason
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judging method
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disposition
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Closing and no operation.
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Control circuit has no voltage, incorrect wiring and plug
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Test the power supply voltage by
universal meter, which should be consistent with the relevant
specification of the instruction.
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According to the specification of the instructions, wiring
correctly so that each coil imposed the required rated control supply voltage
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the coil burned or broken
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Checking by
universal meter
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Change the coil or repair the broken
wire
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diode arcing
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Replace the diode
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The terminals of the two coils
connected reverse.
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Reverse connection
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Change to correct connection.
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Closing, and mechanical hook can not work
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Control power supply
voltage is too low.
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Test the power supply voltage by the universal meter to see if it is up than 70% of the
rated control power supply voltage.
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Reduce the voltage drop and increase
the control power supply voltage.
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Energized time of the closing coil is
short.
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Increase the delay time according to the electric schematic
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Increase the capacitance
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The mechanism of the closing part is
stuck.
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Checking if the closing electromagnet
and armature are in the place
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Adjustment
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The vacuum interrupter is broken
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Checking if the interrupter has crack and breakage, if there
is no negative pressure, if the withstand voltage between the contacts has
arcing.
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replace interrupter
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the maintaining hook is not in place
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The reason that the maintaining hook
can not pass opening rotation axis: tension spring force of the maintaining hook
is small; the rotation angle of the opening rotation axis is excessive; the re
bounce of the tension spring force on the rotation axis is excessive.
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Readjust
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the maintaining hook can not fasten.
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The maintaining hook passed the
opening rotation axis, but after the closing coil is cut off the electricity,
the maintaining hook can not fasten, the reason; the
rotation angle of the opening rotation axis is too small,
the re bounce of the tension spring force on the rotation axis is small.
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Readjust
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The reason of the under voltage tripper
unfasten: under voltage coil burned, the applied voltage to the under voltage
coil is not correct, the
travel of the plate is too small, making the pick up voltage
of the under voltage coil is too high.
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Change the under voltage coil or increase the voltage, adjust
the plate to make the pick up voltage of the under voltage coil below 75% of the
rated control power supply voltage.
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not opening
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Under voltage tripper can not trip.
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The spring force of the under voltage
tripper is small, the
travel of the plate is too big.
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The tension spring force of the
maintaining hook is too big, which makes the force of the maintaining hook is
big.
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readjust
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Shunt tripper can not trip.
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Rotation angle of the opening rotation
axis is too big, which makes the stroke of the shunt electromagnet increased,
and the pick up voltage is too high, the coil burned.
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replace the
coil
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Manual open it and
can not trip.
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the screw loosed or the manual
operation is not in place.
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Readjust
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The closing coil is not cut off the
electricity.
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The contacts of the middle relay and
auxiliary switch are not breaking.
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Change the relay or auxiliary switch,
readjust and clean the contact.
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mechanism stuck
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Manually making and breaking for
several times.
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readjust
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the contact of the vacuum interrupter fusion welding
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checking by universal meter
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replace the vacuum
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coil burned
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closing coil or shunt coil burned
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the rated control power supply voltage
is inconsistent, auxiliary switch can not be breaking, make the coil energized
for a long time.
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Change to the correct rated control
power supply voltage, adjust or replace the auxiliary switch and coil.
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under voltage coil burned
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short circuit due to bad insulation
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replace the coil
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arcing
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The vacuum interrupter lost vacuum
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test the withstand voltage of between
the contacts is 10KV/1min, arcing, even if applied voltage
repeatedly, the pressure can not be increased.
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replace the
vacuum interrupter
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temperature of the main circuit is too high
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fastening screw loosed
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checking each fastening screw of the main circuit
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tighten the screw
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no overtravel
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Checking if there is overtravel after several times making
and breaking.
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readjust
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the contact wears excessively
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conductive rod short (compared checking)
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replace the interrupter
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