GB1601850A

GB1601850A - Enclosed switchgear

Info

Publication number: GB1601850A
Application number: GB2396178A
Authority: GB
Original assignee: Tokyo Shibaura Electric Co Ltd
Current assignee: Toshiba Corp
Priority date: 1978-05-30
Filing date: 1978-05-30
Publication date: 1981-11-04

Description

(54) ENCLOSED SWITCHGEAR (71) We, TOKYO SHIBAURA ELECTRIC COMPANY LIMITED, a Japanese Company, of 72, Horikawa-cho, Saiwai-ku, Kawasaki-shi, Kanagawa-ken, Japan, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to electrical switchgear and in particular to enclosed switchgear of the draw-out type which includes an electrical circuit breaker displaceably mounted in a cubicle. Such circuit breakers are provided with load terminals and corresponding load terminals are provided on the cubicle.The circuit breaker is truck mounted and is displaceable between a position known as the Connect position, in which the load teminals on the breaker and those on the cubicle are in engagement, and Disconnect and Test positions, in which the load terminals on the circuit breaker and those on the cubicle are disengaged.

The circuit breaker has load contacts, electrical drive means for opening and closing the load contacts, and auxiliary contacts operable with the load contacts. In the Connect and Test positions, the circuit breaker is connected to external circuits by which the drive means can be operated and by which signals can be passed through at least one of the auxiliary contacts to indicate the operating condition of the load contacts.

1n the Disconnect position, the drive means for the load contacts cannot be operated to close the load contacts and it is desirable that the open condition of the load contacts should be indicated in this position.

According to the present invention, a drawout out type electrical switchgear comprises an electrical circuit breaker displaceable in a cubicle between a Connect position in which load terminals on the circuit breaker are in engagement with corresponding load terminals on the cubicle, and Disconnect and Test positions in both of which positions the load terminals on the current breaker and those on the cubicle are disengaged, the circuit breaker having load contacts and two pairs of auxiliary contacts, one pair being normally open and the other pair being normally closed, means for opening and closing the load contacts and the auxiliary contacts being operable with the load contacts such that, when the load contacts are closed, the normally open pair and normally closed pair of auxiliary contacts become closed and open respectively, first terminal means mounted on the circuit breaker and connected to the auxiliary contacts, second and third terminal means mounted in spaced apart relation on the cubicle such that the first and second terminal means are in engagement with each other when the circuit breaker is in the Connect position and said first and third terminal means are in engagement with each other when the circuit breaker is in the Test position, switch means with normally closed contacts connected electrically in parallel with those ones of the second and third terminal means which in the Connect and Test positions of said circuit breaker engage with the first terminal means in said circuit breaker which are connected through said normally closed pair of auxiliary contacts, and actuating means for said switch means, said actuating means being arranged to actuate said switch means to open said normally closed contacts thereof only in the Connect or Test positions of said circuit breaker, said switch means in the Disconnect position of said circuit breaker having its contacts closed such that electrical signals indicative of the open state of the load contacts of the circuit breaker can be passed through said switch means to a circuit external of the circuit breaker.

In a preferred arrangement, said actuating means comprises two separate pins spaced apart on the circuit breaker in the direction of movement of the circuit breaker, said pins being operable to actuate the switch to open the contacts thereof when the circuit breaker is in the Connect and Test positions.

In the Connect position of the circuit breaker in the cubicle, the drive means for the breaker contacts can be driven and the condition of the breaker load contacts is also apparent by way of the auxiliary contacts.

Similarly, in the Test position of the circuit breaker, the drive means can be driven and the condition of the breaker load contacts is indicated. In the Disconnect position of the circuit breaker, the drive means cannot be driven but the switch means permits the open conditions of the breaker load contacts to be indicated.

In order that the invention may be more readily understood it will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure la is a side elevation of the apparatus, Figure lb is a sectional end view on the line B-B of Figure la, Figure 2 is an end view of part of the apparatus showing the control means contained within the line II of Figure lb, Figure 3 is a side view on the line Ill-Ill of Figure 2, Figure 4 is a sequence chart showing the relationship between the control means and switch means in each of the positions of the circuit breaker, and Figures 5a, 5b and Sc are sequence charts showing the connection relationship for the Test, the Disconnect and Connect positions of the circuit breaker respectively.

Electrical switchgear of the draw-out type comprises a cubicle 10 including an inner frame and a truck mounted circuit breaker 12 movably mounted in the cubicle. At the rear of the circuit breaker there are load terminals 14 which are engageable with corresponding load terminals on the cubicle.

The cubicle also contains control means for supplying signals to the drive means of the circuit breaker for opening and closing the load contacts of the circuit breaker and for receiving signals via the auxiliary contacts from the circuit breaker which are indicative of the operating condition of its load contacts. The control circuit 13 has first terminal means 13c in the form of a plurality of terminals upstanding from the circuit breaker and arranged normal to the direction of movement of the circuit breaker. Second and third terminal means in the form of separate terminals 13a and 13b are mounted on the cubicle and are arranged in the direction of movement of the circuit breaker.

The position of the terminals is such that the terminals 13c make contact with the terminals 13b, when the circuit breaker is in its Connect position with its load terminals in engagement with the corresponding load terminals on the cubible but, in the Test position, where the circuit breaker has been displaced forward so that its load terminals are disconnected from those on the cubicle, terminals 13c are in engagement with a mi- nals 13a. In the intermediate position, known as the Disconnect position, the terminals 13c are not in engagement with either of the terminals 13a or 13b and the load terminals on the circuit breaker are disconnected from those on the cubicle.

Means including a switch 15 having normally closed contacts are mounted in the cubicle and the switch is actuated by actuating means including a member 16 which in turn is actuated by the circuit breaker.

Referring particularly to Figures 2 and 3, first and second pins 17a and 17b upstand from the circuit breaker 12 and are aligned in the direction of movement of the circuit breaker. Movement of the breaker causes the pins to engage with the member 16 causing the switch 15 to be actuated to open the switch contacts. The pins 17a, 17b are so positioned that they engage the member 16 and actuate switch 15 to open its contacts in the Connect and the Test positions of the circuit breaker only.

A guide frame 18a mounted on the frame of the cubicle carries the cranked member 16 which is displaceable vertically on a pin 19 forming part of the guide frame. The upward movement of the member 16 is opposed by a compression spring 20. A second guide 18b, also mounted on the frame 11, carries a horizontal pin 21 with a roller 22 at one end.

The roller is biased towards the member 16 by a compression spring 20. The end of the pin 21 away from the roller 22 engages with the actuating means of the switch 15.

When the circuit breaker 12 is moved into the Connect position or the Test position, one or other of the pins 17a, 17b engages the cranked member 16, which is tapered at its lower end, causing the member to rise and this displaces the pin 21 horizontally to actuate the switch to open its contacts.

If the stroke of the actuating member of the switch 15 is 12, then the crank of the member 16 is made equal to 12. In pushing up the member through a distance 13, the pin 21 is displaced horizontally through a distance 12 which is sufficient to actuate the switch. The lower end of the member 16 is tapered such that, when it is engaged by one of the pins 17a, 17b, the member 16 is lifted through a distance 14 which is always greater than that necessary to displace the pin 21 through the distance 12.

From Figure 4 it can be seen that the control means 13 is connected to the circuit breaker when it is in its Test position and also in its Connect position. In these positions, the position switch 15 has been actuated to open the normally closed contacts of that switch.

Referring to Figures 5a, 5b and 5c, it can be seen that it is possible to pass signals through the circuit breaker on line b in the Test position because terminals 13a and 13c are in engagement. In the Disconnect position shown in Figure Sb, although the terminals 13c, 13a and 13b are not in engagement, a signal can be passed along line b through the switch 15 which has its contacts in the closed position.

In the Connect position, shown in Figure 5c, since the switch 15 is turned OFF, that is its contacts are open, contact with the circuit breaker can be made between the terminals 13b and 13c.

It is thus possible to obtain from the circuit breaker signals indicative of the operating condition of its load contacts when the circuit breaker is placed in its Connect or its Test position.

The auxiliary contacts CB and CB-b are connected to the contacts of the circuit breaker so that they bear a fixed relationship with the condition of the load contacts of the breaker. CB is normally open but closes when the load contacts are closed and CB-b is normally closed but opens when the load contacts are closed.In the arrangement shown in Figures 5a, 5b and 5c, the contacts POS-b of the means 15 are connected in parallel with the contacts CB-b so that, even when the breaker is in its Disconnect position, as shown in Figure 5b, electrical signals can be passed through the contacts POS-b to a circuit external of the breaker to indicate that the load contacts on the breaker are closed WHAT WE CLAIM IS: 1.Draw-out type electrical switchgear comprising an electrical circuit breaker displaceable in a cubicle between a Connect position in which load terminals on the circuit breaker are in engagement with corresponding load terminals on the cubicle, and Disconnect and Test positions in both of which positions the load terminals on the circuit breaker and those on the cubicle are disengaged, the circuit breaker having load contacts and two pairs of auxiliary contacts, one pair being normally open and the other pair being norrflally closed, means for opening and closing the load contacts and the auxiliary contacts being operable with the load contacts such that, when the load contacts are closed, the normally open pair and normally closed pair of auxiliary contacts become closed and open respectively, first terminal means mounted on the circuit breaker and connected to the auxiliary contacts, second and third terminal means mounted in spaced apart relation on the cubicle such that the first and second terminal means are in engagement with each other when the circuit breaker is in the Connect position and said first and third terminal means are in engagement with each other when the circuit breaker is in the Test position, switch means with normally closed contacts connected electrically in parallel with those ones of the second and third terminal means which in the Connect and Test positions of said circuit breaker engage with the first terminal means on said circuit breaker which are connected through said normally closed pair of auxiliary contacts, and actuating means for said switch means, said actuating means being arranged to actuate said switch means to open said normally closed contacts thereof only in the Connect or Test positions of said circuit breaker, said switch means in the Disconnect position of said circuit breaker having its contacts closed such that electrical signals indicative of the open state of the load contacts of the circuit breaker can be passed through said switch means to a circuit external of the circuit breaker.

2. Draw-out type electrical switchgear as claimed in claim 1, in which said actuating means comprises two separate pins spaced apart in the direction of movement of the circuit breaker, said pins being operable to actuate the switch to open the contacts when the circuit breaker is in the Connect and Test positions.

3. Draw-out type electrical switchgear substantially as hereinbefore described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

Test position because terminals 13a and 13c are in engagement. In the Disconnect position shown in Figure Sb, although the terminals 13c, 13a and 13b are not in engagement, a signal can be passed along line b through the switch 15 which has its contacts in the closed position.

In the Connect position, shown in Figure 5c, since the switch 15 is turned OFF, that is its contacts are open, contact with the circuit breaker can be made between the terminals 13b and 13c.

It is thus possible to obtain from the circuit breaker signals indicative of the operating condition of its load contacts when the circuit breaker is placed in its Connect or its Test position.

The auxiliary contacts CB and CB-b are connected to the contacts of the circuit breaker so that they bear a fixed relationship with the condition of the load contacts of the breaker. CB is normally open but closes when the load contacts are closed and CB-b is normally closed but opens when the load contacts are closed.In the arrangement shown in Figures 5a, 5b and 5c, the contacts POS-b of the means 15 are connected in parallel with the contacts CB-b so that, even when the breaker is in its Disconnect position, as shown in Figure 5b, electrical signals can be passed through the contacts POS-b to a circuit external of the breaker to indicate that the load contacts on the breaker are closed WHAT WE CLAIM IS: 1.Draw-out type electrical switchgear comprising an electrical circuit breaker displaceable in a cubicle between a Connect position in which load terminals on the circuit breaker are in engagement with corresponding load terminals on the cubicle, and Disconnect and Test positions in both of which positions the load terminals on the circuit breaker and those on the cubicle are disengaged, the circuit breaker having load contacts and two pairs of auxiliary contacts, one pair being normally open and the other pair being norrflally closed, means for opening and closing the load contacts and the auxiliary contacts being operable with the load contacts such that, when the load contacts are closed, the normally open pair and normally closed pair of auxiliary contacts become closed and open respectively, first terminal means mounted on the circuit breaker and connected to the auxiliary contacts, second and third terminal means mounted in spaced apart relation on the cubicle such that the first and second terminal means are in engagement with each other when the circuit breaker is in the Connect position and said first and third terminal means are in engagement with each other when the circuit breaker is in the Test position, switch means with normally closed contacts connected electrically in parallel with those ones of the second and third terminal means which in the Connect and Test positions of said circuit breaker engage with the first terminal means on said circuit breaker which are connected through said normally closed pair of auxiliary contacts, and actuating means for said switch means, said actuating means being arranged to actuate said switch means to open said normally closed contacts thereof only in the Connect or Test positions of said circuit breaker, said switch means in the Disconnect position of said circuit breaker having its contacts closed such that electrical signals indicative of the open state of the load contacts of the circuit breaker can be passed through said switch means to a circuit external of the circuit breaker.
2. Draw-out type electrical switchgear as claimed in claim 1, in which said actuating means comprises two separate pins spaced apart in the direction of movement of the circuit breaker, said pins being operable to actuate the switch to open the contacts when the circuit breaker is in the Connect and Test positions.
3. Draw-out type electrical switchgear substantially as hereinbefore described with reference to the accompanying drawings.