METHOD AND DEVICE FOR INTERLOCKING

Abstract: The present invention concerns a method and a device for interlocking a disconnecting breaker. During interlocking of a single-poled or multiple-poled disconnecting breaker, the actuator of the breaker is first interlocked both electrically and mechanically. When the breaker is in the open position, the distance between the contacts of the breaker comprises the conductor spacing for the isolation function. The electrical and mechanical interlocking of the actuator is indicated both electrically and mechanically. Subsequently, the link system of the breaker is mechanically interlocked. The link system is locked in the interlocked position. Interlocking of the link system is indicated by at least one indicator. Interlocking of the actuator of the breaker can be controlled manually via a key- and lock device, or remotely.

Description: METHOD AND DEVICE FOR INTERLOCKING Technical field The present invention concerns a method and a device for interlocking a disconnecting breaker. The prior art Safety regulations have earlier required a disconnector with a visually open conductor spacing during work on, for example, a high tension switch gear. According to the traditional solution, a breaker and a disconnector have together ensured that the section of the equipment where the work is to be carried out is disconnected. This type of solution requires at least one, and often two, disconnectors with demanding maintenance in order to ensure their correct function. Each disconnector must be correctly installed with a foundation that requires space and expensive installation time. The present invention is intended to solve the problems described above. The intention is to provide a compact solution, reliable from the point of view of safety, that is simple to manufacture and cost- effective for the customer. The construction permits manufacture of the parts according to known technology. Summary of the invention The present invention concerns a method and a device for interlocking a disconnecting breaker. The earlier requirement for a visually open disconnector has been replaced according to new regulations by the requirement for a reliable indication that the section of the equipment is disconnected. During interlocking of a single- or multiple-poled disconnecting breaker that includes a linkage system, known as a "rod system", for closing operation and opening of the contacts of the breaker, the actuator of the breaker is first interlocked both electrically and mechanically. When the breaker is in the open position, the distance between the contacts of the breaker constitutes the conductor spacing of the disconnecting function. The electrical and mechanical interlocking of the actuator is indicated both electrically and mechanically. The interlocking of the actuator of the breaker is achieved with the aid of an electromagnetic blocking unit that can be operated with a hand-operated key- and lock device. The blocking unit can in one preferred embodiment be operated by remote control. In one preferred embodiment, operation of the hand-operated key- and lock device controls an electromagnet that interlocks a locking package of the actuator of the breaker both by breaking the operating current to the locking package and by mechanically blocking the locking package. The key device is freed from the lock device following the interlocking of the actuator of the breaker and is used in a second lock device for mechanical interlocking of the rod system with the aid of a blocking unit. The rod system is locked in the interlocked condition with a second key device and a third lock device. The interlocking of the rod system is indicated by at least one indicator. According to one embodiment of the device, the second key device is used with a fourth lock device in order to free a blocking unit, which makes it possible to move an earth knife or other earth device. Once the earth knife has been connected to the breaker, the earth knife is blocked in its connected position and locked with the second key device and the fourth lock device. The electrical and mechanical interlocking of the actuator of the breaker can in one preferred embodiment be achieved with a remote-controlled interlocking device. The remote-controlled interlocking of the actuator of the breaker is indicated by electrical and mechanical indicators on the breaker and by indicators on the remote-control unit. The remote-controlled interlocking device includes the operation of a blocking device for the earth knife, after which movement of the earth knife is accompanied by interlocking of the rod system. The system according to the invention is very reliable from the point of view of safety due to the interlocking in one preferred embodiment being performed by the exchange of keys, and due to electrical and mechanical indicators showing in different ways that the breaker is interlocked. Brief description of the figures Fig. 1 shows a sketch of the principle of a disconnecting breaker for a three-phase system. Fig. 2 shows a sketch of the principle of a disconnecting breaker for a single-phase system. Fig. 3 shows an actuator for operation of breakers. Fig. 4 shows interlocking of the rod system with a blocking plate and lock. Fig. 5 shows an actuator for an earth knife together with interlocking of the earth knife with a blocking unit equipped with a lock. Fig. 6 shows interlocking of the rod system during remote control. Detailed description of preferred embodiments Fig. 1 shows a sketch of the principle of a disconnecting breaker for three poles. An actuator 10 controls a link system, known as a rod system, 20 which connects the poles together and controls the positions of the contacts 30 of the breaker. The positions of the contacts 30 of the breaker are indicated on each pole, for example with a mechanical arrow 70. An earth knife 40 is controlled by its own actuator 50, which is in direct electrical connection with the actuator 10 through a cable 60 connected between the actuators. When the disconnecting breaker is interlocked, the actuator 10 is first interlocked both electrically and mechanically with the aid of an electromagnet 12. After this, the rod system 20 of the breaker 30 is interlocked mechanically. The indication is achieved in one preferred embodiment electrically with a lamp and mechanically with, for example, an arrow. The key- and lock device in one preferred embodiment is a Castel lock with the associated keys. When both the actuator 10 and the rod system 20 are interlocked, manual operation and locking of the earth knife 40 according to known technology are possible. Fig. 2 shows a sketch of the principle of an disconnectingbreaker for a single pole. An actuator 10 controls a link system, also known as a rod system, 20 which controls the position of the contacts 30 of the breaker. The positions of the contacts 30 of the breaker are indicated, for example, with a mechanical arrow 70. An earth knife 40 is controlled by its own actuator 50, which is in direct electrical connection with the actuator 10 through a cable 60 connected between the actuators. When the single-pole disconnectingbreaker is interlocked, the breaker is interlocked according to the same principle as the three-pole disconnectingbreaker. Fig. 3 shows the actuator 10 for control of the rod system 20 and thus the position of the contacts 30, which includes a locking package 11 that controls the position of the breaker 30 together with an electromagnet 12 equipped with a mechanical locking shackle 13 or equivalent device. When a first key 18 is turned in the lock 14, the electromagnet 12 releases, whereby operating current to the locking package 11, which is used for control of the rod system and thus the breaker, is interrupted. Under the condition that the breaker is in the OFF position, a shackle 13 is released downwards and mechanically blocks movement of the locking package from the OFF position to the ON position. Indication that interlocking of the actuator is achieved, for example, by the lighting of a green lamp on the external surface of the actuator and by the pointing towards a green field of a mechanical arrow 16 inside the actuator. An auxiliary contact 17 indicates the position of the breaker. When the breaker is OFF and the actuator is interlocked, a signal is sent from the auxiliary contact 17 via the cable 60 to the actuator 50 of the earth knife. This is one of the conditions that must be satisfied if movement of the earth knife is to be possible. If the breaker is in the ON position when the actuator is interlocked, the breaker can in one preferred embodiment be automatically breakered over to the OFF position. In one preferred embodiment the actuator of the breaker can be interlocked with the breaker in the ON position. The indicator 70 then indicates that the breaker is in the ON position. Movement of the earth knife is not possible in this condition since this requires a signal from the auxiliary contact 17 via the cable 60 to the actuator of the earth knife. Fig. 4 shows part of a link system, known as a rod system, 20 for operation of the contacts 30 of the breaker. The rod system 20 is equipped with a moving part 21 that is in an inner position when the breaker is ON and an outer, visible position when the breaker is OFF. By tunring the first key 18 in a second lock 22, manual movement of a blocking plate 23, or other blockage device, is made possible. The blockage plate 23 is pushed in a sideways direction and locked in place with a second key 24 in a third lock 25 such that the moving part 21 and thus the rod system 20 are locked into their outer positions. The interlocking of the rod system can be indicated with, for example, an arrow. Fig. 5 shows the earth knife 40 with its actuator 50. The position of the earth knife is controlled by a link system 51. Fig. 6 shows the design of the rod system when remote-controlled interlocking is used. Movement of the earth knife involves movement of the blocking plate 23 via a rotatable disk 80.

Claims: Claims 1. Method for interlocking a breaker for a single-pole or multiple-pole mechanical switching device that includes a link system for coupling of the poles, characterised in that the actuator of the breaker is interlocked both electrically and mechanically, whereby the electrical and mechanical interlocking is indicated both electrically and mechanically by means of respective indicators. 2. Method according to claim 1, characterised in that the electrical and mechanical interlocking of the actuator of the breaker is achieved by means of a hand- operated key- and lock device. 3. Method according to claim 2, characterised in that the operation of the key- and lock device releases an electromagnetic blocking unit that interlocks a locking package on the actuator of the breaker. 4. Method according to claim 2, characterised in that the electrical and mechanical interlocking of the actuator of the breaker is carried out with the breaker in the open position, whereby the distance between the contacts comprises the conductor spacing for the disconnecting. 5. Method according to claim 2, characterised in that the electrical and mechanical interlocking of the actuator of the breaker is carried out with the breaker in the closed position, whereby the hand-operated key- and lock device achieves an automatic change of the breaker from the closed to the open position, whereby the distance between the contacts constitutes the conductor spacing for the isolation function. 6. Method according to either of claim 4 or 5, characterised in that the key device is freed from the lock device following the interlocking of the actuator of the breaker and is used in a second lock device for mechanical interlocking of the link system with the aid of a blocking device, which interlocking is locked by a second key device with a third lock device. 7. Method according to claim 6, characterised in that the interlocking of the link system is indicated by at least one indicator. 8. Method according to claim 6, characterised in that the second key device is used with a fourth lock device for mechanical unlocking of the actuator for an earth knife or equivalent earth device, which fourth lock device, after connection of the earth knife to the breaker, is locked with the second key device and the fourth lock device. 9. Method according to claim 2, characterised in that the electrical and mechanical interlocking of the actuator of the breaker is carried out with the breaker in the closed position, whereby the key device is blocked into the lock device following the interlocking of the actuator of the breaker. 10. Method according to claim 1, characterised in that the electrical and mechanical interlocking of the actuator of the breaker is achieved by means of a remotely controlled interlocking device. 11. Method according to claim 10, characterised in that the remotely controlled interlocking of the actuator of the breaker is indicated by electrical and mechanical indicators on the actuator and by indicators on the remote-control unit. 12. Method according to claim 10, characterised in that the electrical and mechanical interlocking of the actuator of the breaker is carried out with the breaker in the open position, whereby the distance between the contacts comprises the conductor spacing for the disconnecting function. 13. Method according to claim 12, characterised in that the interlocking device includes mechanical movement of a blocking device for an earth knife, after which movement of the earth knife involves interlocking of the link system. 14. Method according to claim 13, characterised in that the interlocking of the link system is indicated by at least one indicator. 15. Device for interlocking of a breaker for a single-poled or multiple-poled mechanical switching device that includes link systems for connection of the poles, including blocking units for interlocking of the actuator of the breaker characterised in that it includes an electromagnet that on release interlocks a locking package in the actuator of the breaker both electrically and mechanically, whereby the electrical and mechanical interlocking is indicated both electrically and mechanically by means of the relevant indicators.

Inventors: BORG ULF, LINDER HANS, BORG, ULF, LINDER, HANS
Applicants: ABB AB, BORG ULF, LINDER HANS, BORG, ULF, LINDER, HANS
Application year: 2000
Main classification: H01H9
IPC codes: H01H9, H01H33