CA1112716A - Monitoring the condition of an insulator - Google Patents
Monitoring the condition of an insulatorInfo
- Publication number
- CA1112716A CA1112716A CA320,145A CA320145A CA1112716A CA 1112716 A CA1112716 A CA 1112716A CA 320145 A CA320145 A CA 320145A CA 1112716 A CA1112716 A CA 1112716A
- Authority
- CA
- Canada
- Prior art keywords
- electrically conductive
- insulator
- pylon
- leakage current
- predetermined value
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Abstract
ABSTRACT OF THE DISCLOSURE
A method of continuously monitoring the condition of a power transmission line insulator while it is in service, in which part of the insulator is bypassed by conductive means and in which, when the leakage current passed by the insulator and flowing through the conductive means exceeds a predetermined value, the conductive means is severed by a detonator or other explosive charge and actuating means is actuated which is operative to give a remote indication. Also a sensing and actuating device for use in the method, having conductive means and being adapted to be attached to an insulator so as to bypass part of it, which includes a detonator or other explosive charge adapted to sever the conductive means when leakage current through it exceeds a predetermined value and actuating means in the form of a mercury switch which is operable to give a remote indication when this happens.
A method of continuously monitoring the condition of a power transmission line insulator while it is in service, in which part of the insulator is bypassed by conductive means and in which, when the leakage current passed by the insulator and flowing through the conductive means exceeds a predetermined value, the conductive means is severed by a detonator or other explosive charge and actuating means is actuated which is operative to give a remote indication. Also a sensing and actuating device for use in the method, having conductive means and being adapted to be attached to an insulator so as to bypass part of it, which includes a detonator or other explosive charge adapted to sever the conductive means when leakage current through it exceeds a predetermined value and actuating means in the form of a mercury switch which is operable to give a remote indication when this happens.
Description
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THIS INVENTION relates -to the monitoriny of the condition of an electrical power -transmission line insulator.
More particularly it relates to a me-thod of continuously monitoring -the condi-tion of an electrical insulator while in service, and -to a sensing and actuatin~ device ancl to a monitoring ins-tal.lation for use in such method.
According to the invention there is provided a me-thod of continuously monitoring the condition of an electrical power transmission line insul.ator while it is in service, comprising -the steps of bypassing part of the insulator to establish an electrically conductive pa-th between a power line pylon and a point on sa:id insulator insulated from the power line pylon to conduct substantially all of the leakage current through said conductive path, automatically removing the bypass when the leakage current exceeds a predetermined value, and rendering the previously bypassed part of the insulator operative as insulation without a bypassing electrically conduc-tive path between said point on the insulator and the pylon, actuating an indicating means to indicate that the leakage curren-t has exceeded said predetermined value.
:The bypass may be automatically removed only when the leakage current exceeds a predetermined value, which may be at .~ least 100 mA. The bypass may be removed by causing the leakage current, when it has reached the predetermined value, to de-tonate explosive means which is operative to sever the conductive path.
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Further according -to -the invention -there is provided a device for monitoring a condition of power -transmission llne insula-tors on a power line pylon comprising an electrically conductive element for connecti:ng to -the power line pylon, electrically conductive means for connection to an insulator a-t a point insulated from the power line pylon, sensing means connec-ted between said electrically conductive element and said electrically conductive means for carrying in a conductive path with said electrically conductive element and said electrically conduc-tive means, subs-tantially all of the leakage current be-tween the insulated point and the pylon to electrically bypass -the insulation between the insulated point and -the pylon, said sensing means including severing means responsive to the leakage current between the insulated point and the pylon to cause a break between said electrically conductive element and said electrically conductive means when the leakage current exceeds a predetermined value in said conductive path and to render the previously bypassed insulated point and the pylon without a bypass, and indicating means to indicate that the leakage current has exceeded a predetermined value actuated by said severing means moving said electrically conductive element and said electrically conductive means apart.
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~ he severing means may comprise an electrically detonat-able detona-tor having a fuse wire which forms part of the conductive means and which is detonatable upon the leakage current passing through the conductive means exceeding said predetermined value. The severing means may also include an explosive charge in which the detonator is embeddedO
THIS INVENTION relates -to the monitoriny of the condition of an electrical power -transmission line insulator.
More particularly it relates to a me-thod of continuously monitoring -the condi-tion of an electrical insulator while in service, and -to a sensing and actuatin~ device ancl to a monitoring ins-tal.lation for use in such method.
According to the invention there is provided a me-thod of continuously monitoring the condition of an electrical power transmission line insul.ator while it is in service, comprising -the steps of bypassing part of the insulator to establish an electrically conductive pa-th between a power line pylon and a point on sa:id insulator insulated from the power line pylon to conduct substantially all of the leakage current through said conductive path, automatically removing the bypass when the leakage current exceeds a predetermined value, and rendering the previously bypassed part of the insulator operative as insulation without a bypassing electrically conduc-tive path between said point on the insulator and the pylon, actuating an indicating means to indicate that the leakage curren-t has exceeded said predetermined value.
:The bypass may be automatically removed only when the leakage current exceeds a predetermined value, which may be at .~ least 100 mA. The bypass may be removed by causing the leakage current, when it has reached the predetermined value, to de-tonate explosive means which is operative to sever the conductive path.
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Further according -to -the invention -there is provided a device for monitoring a condition of power -transmission llne insula-tors on a power line pylon comprising an electrically conductive element for connecti:ng to -the power line pylon, electrically conductive means for connection to an insulator a-t a point insulated from the power line pylon, sensing means connec-ted between said electrically conductive element and said electrically conductive means for carrying in a conductive path with said electrically conductive element and said electrically conduc-tive means, subs-tantially all of the leakage current be-tween the insulated point and the pylon to electrically bypass -the insulation between the insulated point and -the pylon, said sensing means including severing means responsive to the leakage current between the insulated point and the pylon to cause a break between said electrically conductive element and said electrically conductive means when the leakage current exceeds a predetermined value in said conductive path and to render the previously bypassed insulated point and the pylon without a bypass, and indicating means to indicate that the leakage current has exceeded a predetermined value actuated by said severing means moving said electrically conductive element and said electrically conductive means apart.
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~ he severing means may comprise an electrically detonat-able detona-tor having a fuse wire which forms part of the conductive means and which is detonatable upon the leakage current passing through the conductive means exceeding said predetermined value. The severing means may also include an explosive charge in which the detonator is embeddedO
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. ~ - . . ~ - - ~ .-In one embodimen-t, the severing means may include a pair of conductive -tubes which fit together -telescopically, thereby establishing electrical contact with one ano-ther, and which are closed a-t their ends remo-te from one another so as together to define an enclosed space, the detonator belng arranged within the enclosed space, and the arrangemen-t being such that the detonator can -then be positioned wi-th:in -the enclosed space so -that, when the de-tonator is detonated, the explosive force causes the two tubes to fly apart, breaking eleetrical eontaet between them and thus severing said eonduetlve path.
The invention further extends to a sensing and aetuating ~.
deviee for monitoring the eondition of a power transmission line insulator, whieh deviee comprises: an eleetrieally eonduetive element for ec)nneeting to a power line pylon; eleetrieally eonductive means for connection to the insulator, intermediate the ends of the insulator; sensing means conneeted between said eleetrieally eonduetive element and said eleetrieally eonduetive means for earrying leakage eurrent from the insulator to the pylon and being responsive to sueh leakage eurrent to cause a break in the eonneetion between the eleetrieally conductive element and the eleetrically conduetive means when the leakage .: .
current exeeeds a predetermined value, whereby said eleetrieally eonduetive element will move elear of said eleetrically conductive means; and aetuating means assoeiated with said eleetrically conductive element for aetuating indieating means remote from the pylon when said eleetrieally eonductive element has moved . - ~3~
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clear of the electrically conduc-tive means so as to indlca-te tha-t the leakage current has exceeded said predetermined value and therefore that the cond:ition of the insulator has fallen below a certain standard.
The actuating means o~ this device may be a posi-tion-sensitlve switch, such as a mercury switch and one or more leads may be connected to -the switch for connecting the switch to the indicating means. The electrically conductive elemen-t can then include a tube o~ electrically conductive material and the lead or leads may pass through the tube.
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lhe invention will now be described in more detail, by way of example, with reference to the accompanyinq drawings.
In the drawings:
Figure 1 shows, diagramatically, part of the cross arm of a power line pylon with a sensing and actuating device in accordance with the invention a-ttached to the insulator string thereof;
Figure 2 is similar to Figure 1 but shows the position of the sensing and actuating device after i-t has been actuated or triggered;
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Figure 3 shows a detail longitudinal cross section : of par-t of -the insulator string with the sensing and actuating device attached thereto;
Figure 4 shows a transverse cross section taken on line IV - IV in Figure 3;
Figure 5 shows a detail cross section of one form of sensi'ng and actuating device;
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Figure 6 shows partly in cross section, part oE
another form of sensing ,nd ctuating device: and '' .B .
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Figure 7 shows a cross section of part of yet another form of sensing and ac-tuating device.
Referring now to F'igures 1 and 2 of the drawings, there is shown a power -transmission line conductor 10 which is suspended from a cross arm 12 of a power line pylon by means of a multiple shed insulator string 16. Near the top encl of the insula-tor s-tring, spaced from -the end, there is mounted a sensing and actuating device 18 which is connec-ted via an electrical connector 20 to -the steelwork of -the cross member 12, ie to earth.
As can be seen in Figures 3 and 4, the sensing and actuating device 18 has attachment means in the form of a bifurcated copper or brass strap 22 whereby it is secured to a metal cap 24 which forms part of the insulator 16. The strap 22 makes electrical con-tact with the cap 24.
Referring now to Figure 5, the sensing and actuating device 18 comprises an explosive cartridge 26, actuating means in the form of a mercury switch 28, the connector 2Q, the strap 22 and wires 30 leading from the strap 22 via an electrically detonatable detonator 32 to the connector 20. The explosive cartridge 26 comprises a glass or PVC tube 34 which is filled with an explos:ive charge 36, the detona-tor 32 being embedded in the charge. The tube is plugged at each end.
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~h~'7~ ~i The strap 22, the wires 30, the fuse wire of the detonator 32 (no-t shown), and the connector 20 form conductive means bypassing the upper part oE the insulator string 16, thereby rendering that par-t of the insulator inoperative.
The strap 22 is secured to one end of the cartridg~
26 by means of a block 38 of epoxy resin, and the connector 20 is secured by means of a block 40, also of epoxy resin, to the other end of the cartridge. The mercury switch 28 is embedded in the block 40 and its -two leads are indicated by reference numeral 42.
The mercury switch 28 has a pair of electrodes 44 which are arranged such that the switch is open when the actuating device 18 is in the horizon-tal position, ie when attached to -the insulator string 16 as shown in Figure 1, and closed when the part thereof which is a-ttached to the connector 20 is in the vertical position, ie when suspended from the connec-tor 20 as shown in Figure 2. --The leads 42 follow the connector 20 and lead down the pylon to a switchboard or the like, which is remote from the insulator 16, where the~ are connected in series with an electric indicator lamp to a source of electrical power. :
Thus, when the mercury switch closes, the indicator lamp will light up. The leads 42 may also lead to a small radio transmitter or other signalling device which will be activate when the mercury switch closes, to give an indication at a ~ 7 -- ~
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- ~ . ` ., remote switchboard. One o-f the leads 42 may of course be connec-ted to earth, ie, to -the connector 20, so that a single lead 42 leading to the lamp or the like will suffice.
In use, when the insulator is in a good condition, it will pass very little leakage current from -the conductor 10 to the pylon. As the insulator becomes dir-ty, due, for example, to pollution, the leakage current increases. The connector 20 and the wires 30 via the detonator 32 will effec-tively bypass -the upper portion of the insulator 16 above the point of attachment of the device 18, so that the leakage current will flow to the steelwor~ of the pylon via the detonator 32. The detona-tor 32 is selected so that it will detonate at a predetermined current, say, for example, one half to three quarter amp. When the deton-ator is detonated, it will detonate the explosive charge 36, thereby positively severing the connection between the block 38 with its strap 22 and the block 40. The connector 20 will then drop away as shown in Figure 2 and cause the mercury switch 28 to close. This will cause the indicator lamp to light up indi-cating that the insulator needs cleaning. Severing of this con-nection will also be effective to remove the bypass, thereby effectively increasing the operative length of the insulator.
This will allow the insulator to be kept in service for some time until the line has to be taken out of service for some other reason. When the line is out of service the insulator can then be cleaned and the device 18 replaced.
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As a variation, shown in Figure 6, the connector 20 may be in the form oE a copper tube 50 which, at lts one end is embedded in -the epoxy resin block 40 and at the other end is attachable to the eross-arm 12 via a short length of flexible, braided copper wire 52 and a connecting lug 54. The leads 42 will in this case pass from the switeh 28 throu~h -the tube 50 to the pylon and thenee to the indieator lamp. The tube 50 will shield the leads 42 in the vieini-ty of the insulator 16.
It will be apprecia-ted -that the switch 28 may, depending on the type of alarm eircuit used, also be arranged so that it is closed when the device 18 is in the position shown in Figure 1 and open when in the position shown in Figure 2.
As a further variation, shown ln Figure 7, the explosive eharge 36 is done away with and the glass or PVC tube 34 replaced by two metal tubes 56 which fit toge-ther telescopically and frictionally and make electrical contact with one another. The end of each tube 56 remote from the other is plugged by means of an electrically insulative plug 57 and embedded in the respective block of epoxy resin 38, 40. The tubes 56 thus define an enclosed space 58. Within the spaee 58 -- ~~
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there are arranged two detonators 60, instead of only one as in the device of Figure 5. ~lso, i-t does no~ contain an additional explosive charge 36, the explosive power oE
the detonators being sufficient for proper operation of the device. Each detonator 60 has one of its leads 62.1 passing through the respective plug 57 and its other lead 62.2 crlmped between the plug and the respective tube 56, -thereby to make electrical con-tact with the tube. The two leads 62.1 are respectively connected to the strap 22 and the connector 20 or tube 50 (see Figures 5 and 6).
The two tubes 56 are covered by a plastics sleeve 64 or some other suitable coating so as herme-tically to seal the enclosed space 58.
When the leakage current in this embodiment exceeds the predetermined value, the detonators 60 will explode and will cause the two -tubes 56 with the blocks 38 and 40 a-ttached thereto to fly apart thus severing the mechanical and electrical connection between the strap 22 and the connector 20 or tube 50. It will be understood that the device illustrated in Figure 7 will also have a mercury switch `~8 embedded in the block 40.
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. ~ - . . ~ - - ~ .-In one embodimen-t, the severing means may include a pair of conductive -tubes which fit together -telescopically, thereby establishing electrical contact with one ano-ther, and which are closed a-t their ends remo-te from one another so as together to define an enclosed space, the detonator belng arranged within the enclosed space, and the arrangemen-t being such that the detonator can -then be positioned wi-th:in -the enclosed space so -that, when the de-tonator is detonated, the explosive force causes the two tubes to fly apart, breaking eleetrical eontaet between them and thus severing said eonduetlve path.
The invention further extends to a sensing and aetuating ~.
deviee for monitoring the eondition of a power transmission line insulator, whieh deviee comprises: an eleetrieally eonduetive element for ec)nneeting to a power line pylon; eleetrieally eonductive means for connection to the insulator, intermediate the ends of the insulator; sensing means conneeted between said eleetrieally eonduetive element and said eleetrieally eonduetive means for earrying leakage eurrent from the insulator to the pylon and being responsive to sueh leakage eurrent to cause a break in the eonneetion between the eleetrieally conductive element and the eleetrically conduetive means when the leakage .: .
current exeeeds a predetermined value, whereby said eleetrieally eonduetive element will move elear of said eleetrically conductive means; and aetuating means assoeiated with said eleetrically conductive element for aetuating indieating means remote from the pylon when said eleetrieally eonductive element has moved . - ~3~
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clear of the electrically conduc-tive means so as to indlca-te tha-t the leakage current has exceeded said predetermined value and therefore that the cond:ition of the insulator has fallen below a certain standard.
The actuating means o~ this device may be a posi-tion-sensitlve switch, such as a mercury switch and one or more leads may be connected to -the switch for connecting the switch to the indicating means. The electrically conductive elemen-t can then include a tube o~ electrically conductive material and the lead or leads may pass through the tube.
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lhe invention will now be described in more detail, by way of example, with reference to the accompanyinq drawings.
In the drawings:
Figure 1 shows, diagramatically, part of the cross arm of a power line pylon with a sensing and actuating device in accordance with the invention a-ttached to the insulator string thereof;
Figure 2 is similar to Figure 1 but shows the position of the sensing and actuating device after i-t has been actuated or triggered;
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Figure 3 shows a detail longitudinal cross section : of par-t of -the insulator string with the sensing and actuating device attached thereto;
Figure 4 shows a transverse cross section taken on line IV - IV in Figure 3;
Figure 5 shows a detail cross section of one form of sensi'ng and actuating device;
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Figure 6 shows partly in cross section, part oE
another form of sensing ,nd ctuating device: and '' .B .
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Figure 7 shows a cross section of part of yet another form of sensing and ac-tuating device.
Referring now to F'igures 1 and 2 of the drawings, there is shown a power -transmission line conductor 10 which is suspended from a cross arm 12 of a power line pylon by means of a multiple shed insulator string 16. Near the top encl of the insula-tor s-tring, spaced from -the end, there is mounted a sensing and actuating device 18 which is connec-ted via an electrical connector 20 to -the steelwork of -the cross member 12, ie to earth.
As can be seen in Figures 3 and 4, the sensing and actuating device 18 has attachment means in the form of a bifurcated copper or brass strap 22 whereby it is secured to a metal cap 24 which forms part of the insulator 16. The strap 22 makes electrical con-tact with the cap 24.
Referring now to Figure 5, the sensing and actuating device 18 comprises an explosive cartridge 26, actuating means in the form of a mercury switch 28, the connector 2Q, the strap 22 and wires 30 leading from the strap 22 via an electrically detonatable detonator 32 to the connector 20. The explosive cartridge 26 comprises a glass or PVC tube 34 which is filled with an explos:ive charge 36, the detona-tor 32 being embedded in the charge. The tube is plugged at each end.
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~h~'7~ ~i The strap 22, the wires 30, the fuse wire of the detonator 32 (no-t shown), and the connector 20 form conductive means bypassing the upper part oE the insulator string 16, thereby rendering that par-t of the insulator inoperative.
The strap 22 is secured to one end of the cartridg~
26 by means of a block 38 of epoxy resin, and the connector 20 is secured by means of a block 40, also of epoxy resin, to the other end of the cartridge. The mercury switch 28 is embedded in the block 40 and its -two leads are indicated by reference numeral 42.
The mercury switch 28 has a pair of electrodes 44 which are arranged such that the switch is open when the actuating device 18 is in the horizon-tal position, ie when attached to -the insulator string 16 as shown in Figure 1, and closed when the part thereof which is a-ttached to the connector 20 is in the vertical position, ie when suspended from the connec-tor 20 as shown in Figure 2. --The leads 42 follow the connector 20 and lead down the pylon to a switchboard or the like, which is remote from the insulator 16, where the~ are connected in series with an electric indicator lamp to a source of electrical power. :
Thus, when the mercury switch closes, the indicator lamp will light up. The leads 42 may also lead to a small radio transmitter or other signalling device which will be activate when the mercury switch closes, to give an indication at a ~ 7 -- ~
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- ~ . ` ., remote switchboard. One o-f the leads 42 may of course be connec-ted to earth, ie, to -the connector 20, so that a single lead 42 leading to the lamp or the like will suffice.
In use, when the insulator is in a good condition, it will pass very little leakage current from -the conductor 10 to the pylon. As the insulator becomes dir-ty, due, for example, to pollution, the leakage current increases. The connector 20 and the wires 30 via the detonator 32 will effec-tively bypass -the upper portion of the insulator 16 above the point of attachment of the device 18, so that the leakage current will flow to the steelwor~ of the pylon via the detonator 32. The detona-tor 32 is selected so that it will detonate at a predetermined current, say, for example, one half to three quarter amp. When the deton-ator is detonated, it will detonate the explosive charge 36, thereby positively severing the connection between the block 38 with its strap 22 and the block 40. The connector 20 will then drop away as shown in Figure 2 and cause the mercury switch 28 to close. This will cause the indicator lamp to light up indi-cating that the insulator needs cleaning. Severing of this con-nection will also be effective to remove the bypass, thereby effectively increasing the operative length of the insulator.
This will allow the insulator to be kept in service for some time until the line has to be taken out of service for some other reason. When the line is out of service the insulator can then be cleaned and the device 18 replaced.
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As a variation, shown in Figure 6, the connector 20 may be in the form oE a copper tube 50 which, at lts one end is embedded in -the epoxy resin block 40 and at the other end is attachable to the eross-arm 12 via a short length of flexible, braided copper wire 52 and a connecting lug 54. The leads 42 will in this case pass from the switeh 28 throu~h -the tube 50 to the pylon and thenee to the indieator lamp. The tube 50 will shield the leads 42 in the vieini-ty of the insulator 16.
It will be apprecia-ted -that the switch 28 may, depending on the type of alarm eircuit used, also be arranged so that it is closed when the device 18 is in the position shown in Figure 1 and open when in the position shown in Figure 2.
As a further variation, shown ln Figure 7, the explosive eharge 36 is done away with and the glass or PVC tube 34 replaced by two metal tubes 56 which fit toge-ther telescopically and frictionally and make electrical contact with one another. The end of each tube 56 remote from the other is plugged by means of an electrically insulative plug 57 and embedded in the respective block of epoxy resin 38, 40. The tubes 56 thus define an enclosed space 58. Within the spaee 58 -- ~~
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there are arranged two detonators 60, instead of only one as in the device of Figure 5. ~lso, i-t does no~ contain an additional explosive charge 36, the explosive power oE
the detonators being sufficient for proper operation of the device. Each detonator 60 has one of its leads 62.1 passing through the respective plug 57 and its other lead 62.2 crlmped between the plug and the respective tube 56, -thereby to make electrical con-tact with the tube. The two leads 62.1 are respectively connected to the strap 22 and the connector 20 or tube 50 (see Figures 5 and 6).
The two tubes 56 are covered by a plastics sleeve 64 or some other suitable coating so as herme-tically to seal the enclosed space 58.
When the leakage current in this embodiment exceeds the predetermined value, the detonators 60 will explode and will cause the two -tubes 56 with the blocks 38 and 40 a-ttached thereto to fly apart thus severing the mechanical and electrical connection between the strap 22 and the connector 20 or tube 50. It will be understood that the device illustrated in Figure 7 will also have a mercury switch `~8 embedded in the block 40.
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Claims (11)
1. A device for monitoring a condition of power trans-mission line insulators on a power line pylon comprising an electrically conductive element for connecting to the power line pylon, electrically conductive means for connection to an in-sulator at a point insulated from the power line pylon, sensing means connected between said electrically conductive element and said electrically conductive means for carrying in a conductive path with said electrically conductive element and said elec-trically conductive means, substantially all of the leakage current between the insulated point and the pylon to electrically bypass the insulation between the insulated point and the pylon, said sensing means including severing means responsive to the leakage current between the insulated point and the pylon to cause a break between said electrically conductive element and said electrically conductive means when the leakage current exceeds a predetermined value in said conductive path and to render the previously bypassed insulated point and the pylon without a bypass, and indicating means to indicate that the leakage current has exceeded a predetermined value actuated by said severing means moving said electrically conductive element and said electrically conductive means apart.
2. The device of claim 1 further characterized by said severing means including an electrically operable detonator having a fuse wire which forms part of said conductive path, said detonator being detonatable upon the leakage current pas-sing through said conductive path exceeding said predetermined value.
3. The device of claim 2 further characterized by said severing means including an explosive charge in which said detonator is embedded.
4. The device of claim 2 further characterized by said severing means including a pair of conductive tubes which fit together telescopically to establish electrical contact with each other and which are closed at their ends remote from one another so as together to define an enclosed space, said detonator positioned within said enclosed space whereupon when said detonator is detonated, an explosive force causes said two tubes to fly apart, breaking electrical contact between them and thus severing said conductive path.
5. A method of continuously monitoring the condition of an electrical power transmission line insulator while it is in service comprising the steps of bypassing part of the insu-lator to establish an electrically conductive path between a power line pylon and a point on said insulator insulated from the power line pylon to conduct substantially all of the leakage current through said conductive path, automatically removing the bypass when the leakage current exceeds a predetermined value and rendering the previously bypassed part of the insulator operative as insulation without a bypassing electrically con-ductive path between said point on the insulator and the pylon, actuating an indicating means to indicate that the leakage cur rent has exceeded said predetermined value.
6. The method of claim 5 further characterized by.
performing the step of automatically removing the bypass when the leakage current exceeds a predetermined value by detonating explosive means to sever said conductive path.
performing the step of automatically removing the bypass when the leakage current exceeds a predetermined value by detonating explosive means to sever said conductive path.
7. A method as claimed in claim 5, wherein said pre-determined value is at least 100 mA.
8. A sensing and actuating device for monitoring the condition of a power transmission line insulator, which device comprises: an electrically conductive element for connecting to a power line pylon; electrically conductive means for con-nection to the insulator, intermediate the ends of the insul-ator; sensing means connected between said electrically con-ductive element and said electrically conductive means for carrying leakage current from the insulator to the pylon and being responsive to such leakage current to cause a break in the connection between the electrically conductive element and the electrically conductive means when the leakage current ex-ceeds a predetermined value, whereby said electrically conduc-tive element will move clear of said electrically conductive means; and actuating means associated with said electrically conductive element for actuating indicating means remote -from the pylon when said electrically conductive element has moved clear of the electrically conductive means so as to indicate that the leakage current has exceeded said predetermined value and therefore that the condition of the insulator has fallen below a certain standard.
9. A sensing and actuating device as claimed in claim 8, wherein the actuating means is in the form of a position sensitive switch.
10. A sensing and actuating device as claimed in claim 9, wherein the position sensitive switch is a mercury switch.
11. A sensing and actuating device as claimed in claim 9, which further comprises one or more leads connected to the switch for connecting the switch to said indicating means; and wherein said electrically conductive element includes a tube of electrically conductive material, said lead or leads passing through the tube.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA320,145A CA1112716A (en) | 1979-01-23 | 1979-01-23 | Monitoring the condition of an insulator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA320,145A CA1112716A (en) | 1979-01-23 | 1979-01-23 | Monitoring the condition of an insulator |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1112716A true CA1112716A (en) | 1981-11-17 |
Family
ID=4113386
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA320,145A Expired CA1112716A (en) | 1979-01-23 | 1979-01-23 | Monitoring the condition of an insulator |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1112716A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114923379A (en) * | 2022-03-25 | 2022-08-19 | 上海芯飏科技有限公司 | Self-adaptive processing method and system for leakage current of electronic detonator priming network |
-
1979
- 1979-01-23 CA CA320,145A patent/CA1112716A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114923379A (en) * | 2022-03-25 | 2022-08-19 | 上海芯飏科技有限公司 | Self-adaptive processing method and system for leakage current of electronic detonator priming network |
| CN114923379B (en) * | 2022-03-25 | 2023-10-27 | 上海芯飏科技有限公司 | Self-adaptive processing method for leakage current of electronic detonator priming network |
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| Date | Code | Title | Description |
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| MKEX | Expiry |