GB2444850A - An apparatus for assisting measurement of the resistances of LV ring main circuits - Google Patents
An apparatus for assisting measurement of the resistances of LV ring main circuits Download PDFInfo
- Publication number
- GB2444850A GB2444850A GB0724265A GB0724265A GB2444850A GB 2444850 A GB2444850 A GB 2444850A GB 0724265 A GB0724265 A GB 0724265A GB 0724265 A GB0724265 A GB 0724265A GB 2444850 A GB2444850 A GB 2444850A
- Authority
- GB
- United Kingdom
- Prior art keywords
- measuring instrument
- measuring
- switches
- measuring apparatus
- conductors
- 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.)
- Granted
Links
- 238000005259 measurement Methods 0.000 title claims abstract description 60
- 238000012360 testing method Methods 0.000 claims abstract description 37
- 230000007935 neutral effect Effects 0.000 claims abstract description 22
- 239000004020 conductor Substances 0.000 claims description 57
- 238000010616 electrical installation Methods 0.000 claims description 10
- 238000002834 transmittance Methods 0.000 claims 1
- 238000010561 standard procedure Methods 0.000 description 6
- 238000000034 method Methods 0.000 description 3
- 238000013461 design Methods 0.000 description 2
- 238000009434 installation Methods 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 238000013208 measuring procedure Methods 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 238000012795 verification Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/16—Measuring impedance of element or network through which a current is passing from another source, e.g. cable, power line
- G01R27/18—Measuring resistance to earth, i.e. line to ground
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/16—Measuring impedance of element or network through which a current is passing from another source, e.g. cable, power line
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/66—Testing of connections, e.g. of plugs or non-disconnectable joints
- G01R31/67—Testing the correctness of wire connections in electric apparatus or circuits
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measurement Of Resistance Or Impedance (AREA)
Abstract
A remotely controlled switch box 102 reconfigures the connections of the live, neutral and earth terminals 101 in a ring main distribution board 102 so that an electrician using a resistance meter 103 can conduct different resistance tests at sockets 115 on the ring main without returning to the distribution board. In particular the live terminals may be coupled to the neutral terminals and then to the earth terminals so that R1+RN and R1+R2 tests may be made. Reference values for these tests are derived from resistance measurements made on the earth, live and neutral loops (figure 3). The switches in the box 102 (figure 5) are controlled reliably in dependence on coded low frequency signals sent from the meter 103.
Description
MEASURING APPARATUS FOR TESTING WIRING OF LOW VOLTAGE ELECTRICAL
INSTALLATIONS
Field of the invention
This invention relates to testing and control of low voltage electrical installations, and in particular, to testing the wiring in ring final circuits.
Technical problem The technical problem solved by this invention is performing simpler and quicker tests on wiring in ring final circuits of electrical installations in such a way that at a distribution board multiple switching of conductors of a tested circuit to a measuring instrument is not necessary. The goal of the invention is that by using a measuring apparatus with only one physical connection of the ring final circuit conductors at the distribution board all the required tests of accuracy of the tested circuit connections can be performed. Moreover, the present invention aims to design an efficient and reliable remote control of the measuring apparatus via test leads and measured conductors.
Current technology Testing the wiring of ring final circuits is a mandatory part of verification of low voltage electrical installations in most countries. During the tests the accuracy of connections of phase, neutral and earth conductors is thoroughly checked. The test requirements are stated in, e.g. the BS7671 standard, in the book by John Whitfield titled >The Electrician's Guide to the 16th Edition of the lEE Wiring Regulations and in the international standard for electrical house installations IEC 60364. A detailed description of testing such a circuit is given in a practical guide >The Inspection and Testing of Electrical Installations" as well.
The established method of testing the wiring connections in a ring final circuit comprises three steps and wires in a distribution board need to be switched five times. The first step consists of measuring resistances ri, rN and r2, i.e. the resistances of phase (L), neutral (N) and earth (PE) conductors connected in the loop. On the basis of results of the resistance mesurements ri, rN and r2, reference values for the next two steps of the test are calculated.
Figure 1 shows the first step of the standard procedure measurement. All the tasks cannot be performed in one step, since every measurement requires the measuring instrument to be connected to another pair of wires, i.e.: -when measuring resistance ri, the measuring instrument is connected with the connection 110, -when measuring resistance rN, the measuring instrument is connected with the connection 111, -when measuring resistance r2, the measuring instrument is connected with the connection 112.
In the second step the resistances R1+RN on electrical sockets are measured. To perform the measurement a cross connection of phase (L) and neutral (N) conductors at a distribution board is required. In the third step the resistances R1+R2 on electrical sockets are measured. To perform the measurement a cross connection of phase (L) and earth (PE) conductors at a distribution board is required. On the basis of comparing the results of resistance measurements R1+RN and Ri+R2 with reference values, obtained in the first step, it is possible to estimate the accuracy of electrical circuit connections in a house installation. Figure 2 illustrates the second and the third step of the measurement following the standard procedure. At the distribution board the following additional manual switchirigs must be done during the procedure: -when measuring resistance R1 RN the switching 120, i.e. the connection of connectors Li and N2 with connectors L2 or Ni; -when measuring resistance R1+R2 the switching 121, i.e. the connection of connectors Li and PE2 with connectors L2 or PE1.
With the method outlined above all the switchings are executed manually, whereas combining the measurements is not possible. Hence the disadvantages of the standard procedure are: -a time consuming measurement, since measurements on electrical sockets need to be carried out separately for each switching.
-a rather complicated measuring procedure and consequently a high probability of mistakes while measuring.
Remote control of the measuring apparatus via test leads, by using a high-frequency signal is described in the patent S120440. The high-frequency signal can be successfully transmitted within several meters, making it suitable to control different apparatus via standard connecting measuring cables, while it is not suitable for larger distances.
The measuring apparatus in the present invention solves the above indicated disadvantages and thus enables quicker, simpler and more reliable execution of wiring tests.
Description of the invention
A solution to the described technical problem is an independent measuring apparatus which, in combination with a measuring instrument, enables quicker and simpler performance of the required measurements when testing the wiring of low voltage electrical installations. The measuring apparatus ensures that at a distribution board, after receiving the commands from the measuring instrument, the required connections are made. Communication from the measuring instrument to the apparatus is directly established via test leads of the instrument, and also via phase, neutral and earth conductors of the measured circuit.
An important feature of the remote control in the present invention is that any source of signal in the measuring instrument, which enables generation of signals with a frequency from 0.5 Hz up to several HZ, can be used as a generator of control signals for the measuring apparatus. The usual testers of low voltage electrical installations include several such sources. If a signal is alternating and has an adequately low frequency, there are no problems in its transmission also via the conductors in one circuit, almost within unlimited distances. The appropriate terminal of a circuit is ensured by predetermined measuring connections and switchings.
The measuring apparatus for testing wiring of low voltage electrical installations in the present invention is described in detail with reference to the accompanying drawings, which show: Figure 1 -Connecting scheme for the first group of measurements, i.e. for measurements of resistances ri, rN and r2 according to the standard procedure.
Figure 2 -Connecting scheme for the second group of measurements, i.e. for measurements of resistances Ri+RN and R1+R2 according to the standard procedure.
Figure 3 -Connecting scheme for the first group of measurements by using the measuring apparatus of the invention.
Figure 4 -Connecting scheme for the second group of measurements by using the measuring apparatus of the invention.
Figure 5 -Block scheme of an example of the measuring apparatus for three-wire single-phase ring final circuit.
Figure 6 -Block scheme of the measuring instrument.
Figure 7 -Outline of the circuit for remote control of switches in the measuring apparatus.
Symbols, used on the drawings and in the descriptions, denote the following: ri: resistance of phase conductor between points Li and L2 in a ring final circuit.
rN: resistance of neutral conductor between points Ni and N2 in a ring final circuit.
r2: resistance of earth conduCtor between points PE1 and PE2 in a ring final circuit.
R1+RN: resistance between phase connector (L) and neutral connector (N) at the measuring point with cross conection of conductors L and N in a distribution board.
(Ri+RN)x: maximum resistance R1+RN, measured across the circuit.
R1+R2: resistance between phase connector (L) and earth connector (PE) at the measuring point with cross conection of conductors L and PE in the distribution board.
(R1+R2)px: maximum resistance R1+R2, measured across the circuit.
Li: first terminal of phase conductor in a ring final circuit.
L2: second (opposite) terminal of phase conductor in a ring final circuit.
Ni: first terminal of neutral conductor in a ring final circuit.
N2: second (opposite) terminal of neutral conductor in a ring final circuit.
PE1: first terminal of earth conductor in a ring final circuit.
PE2: second (opposite) terminal of earth conductor in a ring final circuit.
The measuring apparatus of the invention enables all the required connections of measured conductors to the measuring instrument by using switch array and receiver for control signals for switches in the switch array. Control signals are received by the apparatus via the connecting point of the measuring instrument. When measuring resistance of individual conductors, i.e. resistances of phase, neutral and earth conductors, the connecting point for the measuring instrument is the corresponding measunng connector on the measuring apparatus. When measuring resistance between phase connector and neutral connector at particular measuring points, and between phase connector and earth connector at particular measuring points, the control signals are transmitted via test leads and measured connectors and conductors of the circuit under test. For connection to the ring final circuit, the measuring apparatus has several connecting pins, which are connected to the terminals of the ring final circuit in the distribution board.
Ring final circuits are primarily three-wire one-phase, but they can also be multiple-phase.
With the latter a number of switching combinations have to be ensured when testing. In order to present more clearly the design and operation of the measuring apparatus an example of a measuring apparatus for one-phase three-wire ring final circuit is described. Figure 5 is a block scheme of the example of the measuring apparatus for three-wire one-phase ring final circuit. The measuring apparatus consists of the following parts: five switches, used when performing switching, a receiver for control signals for switches, two resistances, an input for the measuring instrument and connecting pins for connecting the test conductors to the measuring apparatus.
Switch 105, which has its two contacts connected at point LI or L2 in the ring final circuit, is activated for the measurement of resistance ri of the phase conductor. Switch 108, which has its two contacts connected at point Ni or N2 in a ring final circuit, is activated for the measurement of resistance rN of the neutral conductor. Switch 109, which has its two contacts connected at point PE1 or PE2 in the ring final circuit, is activated for the measurement of resistance r2 of the earth conductor.
Switches 105, 108 and 109 have two switch-on contacts. All first contacts of switches 105, 108 and 109 are directly connected to the first pin of input 113 for the signals from the measuring instrument 103, all the other contacts of switches 105, 108 and 109 are connected to the second pin of input 113. A control signal circuit for controlling switches 105, 108 and 109 is formed from the second pin of the input 113, via the current transformer 106 and resistance 107, to the first pin of input 113.
Switch 116 is actived for measuring resistance Ri +RN between the phase connector and neutral connector at the measuring point. Switch 116 has two switch-on contacts, first of which is connected to the first terminal of the phase conductor Li, and the second one to the second terminal of the phase conductor L2. When switch 116 is activated, the terminals Li and L2 of the phase conductor are connected to the changeover contacts of switch 1,19.
When switch 119 is in a deactivated state, its first switching contact connects the first terminal of phase conductor Li to the second terminal of the neutral conductor N2, and its second switching contact connects the second terminal of phase conductor L2 to the first terminal of neutral conductor N2. To measure resistance Ri+RN the measuring instrument 103 is connected between points L and N of the tested circuit, e.g. to electrical socket 115, as shown in figure 4. A circuit for control signal to activate switch 116 is formed from the terminal of neutral conductor Ni via current transformer 106 and resistance 117 to the terminal of phase conductor L2. A circuit for control signal to deactivate switch 116 is formed via contacts of switches 116 and 119.
To measure resistance R1+R2 between the phase connector and earth connector at the measuring point, switches ii6 and 119 are activated. Closed normally-open contacts of switch 116 connect the terminals Li and L2 of the phase conductor to changeover contacts of switch 119. When switch ii 9 is in activated state, its first changeover contact connects the first terminal of phase conductor Li to the second terminal of earth conductor PE2, and its second changeover contact connects the second terminal of phase conductor L2 to the first terminal of earth conductor PEi. To measure resistance Ri +R2 the measuring instrument 103 is connected between the terminals L and PE of the tested circuit, as illustrated in figure 4. A circuit for control signal to activate switches 116 and i 19 is formed from the terminal of neutral conductor Ni via current transformer i06 and resistance i17 to the terminal of phase conductor L2. A circuit for control signal to deactivate switches 116 and 119 is formed via contacts of switches 116 and 1i9.
Control signals to activate or deactivate switches are sent to the measuring apparatus 102 to the same input as measuring signals. A circuit of the control signal is presented in figure 7.
The existing voltage and current sources in the measuring instrument 103 can be used as the sources of control signal, e.g. voltage source 104, which is a source of signal for resistance measurement and has current ability of a few mA. Signal i25 for controlling the measuring apparatus 102 is suitably coded, e.g. a square wave of varying frequency. The control signal is transmitted from source 104 via internal connections 128 of the measuring instrument, test leads 129 of the measuring instrument, via measured conductors 130 and internal connections 131 in the measuring apparatus.
A receiver for control signals in the measuring apparatus comprises simple current transformer 106, amplifier 127 and decision circuit 118. The current transformer 106 is an adequate sensor since it does not influence the measuring signals, flowing in the corresponding conductors, and therefore does not influence the result of the measurements.
AC part of the control signal is adequately transformed via the current transformer 106 and amplifier 127, and transmitted to the decision circuit 118, which executes the command, i.e. it activates a particular switch or a suitable combination of switches, needed for a chosen measurement.
A detailed description of the operation of measuring apparatus is given in the continuation together with an outline of measurement procedures.
Preparation for measuring resistances ri, rN and r2 by using the apparatus of the invention As with the standard procedure, the wires of the circuit under test in the distribution board need to be disconnected before the measurement. In the distribution board 101 are thus accessible wires LI, L2, Nl, N2, PE1 and PE2. The measuring apparatus 102 is connected to the previously mentioned conductors of the ring final circuit in the distribution board and to the measuring instrument 103. Figure 3 illustrates the connections.
Measurement of resistance rI Measurement of resistance rl commences on the measuring instrument 103. The voltage source 104 generates the control signal for the measuring apparatus 102. The control signal flows through the current transformer 106 via amplifier 127 to decision circuit 118, which recognizes the command and activates switch 105. The measuring instrument 103 then executes the standard measurement of resistance. After the completed measurement the measuring instrument 103 generates the command to release all the switches.
Measurement of resistance rN Connection of the measuring apparatus 102 and measuring instrument 103 is the same as with the measurement of resistance rI. Measurement of resistance rN commences on the measuring instrument 103. The voltage source 104 in the measuring instrument 103 generates a control signal for the apparatus 102. The control signal includes the command to activate switch 108 and flows through the current transformer 106. The decision circuit 118 recognizes the command and activates switch 108. The measuring instrument 103 then executes the measurement of resistance rN. After the completed measurement the measuring instrument 103 generates the command to release all the switches.
Measurement of resistance r2 Connection of the measuring apparatus 102 and measuring instrument 103 is the same as with the measurement of resistance ri. Measurement of resistance r2 commences on the measuring instrument 103. The voltage source 104 in the measuring instrument 103 generates a control signal for the apparatus 102. The control signal includes the command to activate switch 109 and flows through the current transformer 106. The decision circuit 118 recognizes the command and activates switch 109. The measuring instrument 103 then executes the measurement of resistance r2. After the completed measurement the measuring instrument 103 generates the command to release all the switches.
The connection of the measuring instrument for measurements of resistances rl, rN and r2 is the same, that is why all three measurements can be combined and performed in one step.
The measuring instrument can within one measuring function compare the results with limit values, and calculate comparison values (rl+rN)/4 and (rl+r2)/4, which function as reference values in the continuation of the test.
Measurement of resistance Ri i-RN The measuring apparatus 102 is connected to accessible wires of the tested circuit in the distribution board. The measuring instrument 103 is connected between the connectors L and N of the tested circuit. The usual connecting point is an electrical socket, e.g. socket 115. Figure 4 shows an example of a measurement connection. Measurement of resistance R1+RN commences on the measuring instrument 103. The voltage source 104 in the measuring instrument 103 generates a control signal for the measuring apparatus 102. The control signal includes the command to activate switch 116 and flows via the test leads of the measuring instrument, the tested socket, its connections to the connectors with the measuring apparatus, and in the measuring apparatus via the current transformer 106. The decision circuit 118 recognizes the command and activates switch 116. The measuring instrument 103 then executes the measurement of resistance. After the completed measurement the measuring instrument 103 generates the command to release all the switches.
Measurement of resistance RI +R2 Connection of the measuring apparatus 102 to the conductors of the tested circuit is the same as with the measurement of resistance R1+RN. The measuring instrument 103 is connected between the connectors L and PE of the circuit under test. The usual connecting point is an electrical socket, e.g. socket 115. This connection is illustrated in figure 4.
Measurement of resistance R1+R2 commences on the measuring instrument 103. The voltage source 104 in the measuring instrument 103 generates a control signal for the measuring apparatus 102. The control signal, which includes the command to activate switches 116 and 119, flows via the test leads of the measuring instrument, the tested socket, its connections to the connectors with the measuring apparatus, and in the measuring apparatus via the current transformer 106. The decision circuit 118 recognizes the command and activates switches 119 and 116. The measuring instrument 103 then executes the standard measurement of resistance. After the completed measurement the measuring instrument 103 generates the command to release all the switches.
If the measuring instrument supports the measurement of resistance between the measuring pins L and N, and L and PE, it is possible to perform the measurement on a socket with a measuring cable, with an appropriate plug. Since the measuring apparatus, given the command of the measuring instrument via the tested conductors, executes the required cross connection in the distribution board, the measurements of resistances R1+RN and R1+R2 can be carried out in one step. The measuring instrument can -inside this step -compare the results with reference values ((rl+rN)14, (rl+r2)/4) and store the maximum results (R1+R2), (R1+RN)MAX. The obtained values of the resistances R1+RN and R1+R2 are comparable to corresponding reference values, if the terminals are right and proper fastened, which is definitely true for sockets, otherwise a significant deviation occurs.
Claims (4)
1. A measuring apparatus for testing the wiring in ring final circuits of low voltage electrical installations, which includes a number of connecting pins, a switch array and a receiver for control signals for switches in the switch array, characteristic in that: -connecting pins enable connection of the measuring apparatus to all the terminals of the tested ring final circuit in the distribution board and to the measuring instrument; -switch array includes a group of on/off switches, intended for the execution of connections of individual phase, neutral and earth conductors to the connector for the measuring instrument, so that each of the on/off switches is activated at its own command, sent from the measuring instrument, and thus enables the resistance measurement of the conductor to which it is connected; -switch array includes a group of combinations of switches, intended for the cross connections of the terminals of phase conductors to the terminals of neutral conductors, and cross connections of the terminals of phase conductors to the terminals of earth conductors in individual phase circuits, so that the combinations of switches enable the resistance measurements between the phase connector and neutral connector, and resistance measurements between the phase connector and earth connector at individual measuring points of the ring final circuit under test.
2. The measuring apparatus according to claim 1, characteristic in that the combination of switches consists of two switches, connected in a series so that the first switch is an on/off switch, whereas the second switch is a changeover switch.
3. The measuring apparatus according to claim 1, characteristic in that the receiver for control signals from the measuring instrument includes a current transformer and decision circuit, and the receiver receives control signals via the connecting point on the measuring instrument.
4. The measuring apparatus according to claims 1 and 2, characteristic in that it receives control signals from the measuring instrument either via test leads in a direct connection to the measuring instrument or via test leads and measured connectors and conductors of ring final circuit under test.
SUMMARY
A measuring apparatus for testing the wiring of low voltage electrical installations enables quicker and simpler execution of the measurements in ring final circuits. In combination with a standard measuring instrument, the measuring apparatus executes all five different required connections in the distribution board. Its particular advantage is quicker and simpler execution of the measurements of resistances Ri --RN and Ri +R2 on electrical sockets in one step, without any reconnection in the distribution board, since the number of sockets in an electrical installation is usually very large. An important feature of the invention is also an efficient and reliable transmittance of control signals from the measuring instrument to the measuring apparatus via test leads and measured conductors.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SI200600286A SI22426A (en) | 2006-12-15 | 2006-12-15 | Measurement device for checking the wiring of low-voltage electrical wiring |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB0724265D0 GB0724265D0 (en) | 2008-01-23 |
| GB2444850A true GB2444850A (en) | 2008-06-18 |
| GB2444850B GB2444850B (en) | 2010-01-06 |
Family
ID=39016487
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB0724265A Expired - Fee Related GB2444850B (en) | 2006-12-15 | 2007-12-12 | Measuring apparatus for testing wiring of low voltage electrical installations |
Country Status (2)
| Country | Link |
|---|---|
| GB (1) | GB2444850B (en) |
| SI (1) | SI22426A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011083029A1 (en) | 2009-12-17 | 2011-07-14 | Prüftech GmbH | Self-monitoring connection line and operating equipment |
| GB2499514A (en) * | 2012-02-14 | 2013-08-21 | Geoffrey Irish | Testing a ring main circuit using a switchable test arrangement e.g. in a wall socket |
| GB2506669A (en) * | 2012-10-07 | 2014-04-09 | John Paul Wasellas | Socket outlet unit including ring main circuit conductor separating means |
| WO2024010511A1 (en) * | 2022-07-06 | 2024-01-11 | Megger Sweden Ab | Method, assembly and sense unit for measuring the frequency response of a plurality of electrical objects |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2376304A (en) * | 2001-03-30 | 2002-12-11 | Iain Edward Welch | Electrical Circuit Testing Aid |
| US7057401B2 (en) * | 2004-03-23 | 2006-06-06 | Pass & Seymour, Inc. | Electrical wiring inspection system |
| WO2008003917A1 (en) * | 2006-07-04 | 2008-01-10 | Interface Technical Components Limited | Apparatus for testing wiring |
-
2006
- 2006-12-15 SI SI200600286A patent/SI22426A/en not_active IP Right Cessation
-
2007
- 2007-12-12 GB GB0724265A patent/GB2444850B/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2376304A (en) * | 2001-03-30 | 2002-12-11 | Iain Edward Welch | Electrical Circuit Testing Aid |
| US7057401B2 (en) * | 2004-03-23 | 2006-06-06 | Pass & Seymour, Inc. | Electrical wiring inspection system |
| WO2008003917A1 (en) * | 2006-07-04 | 2008-01-10 | Interface Technical Components Limited | Apparatus for testing wiring |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011083029A1 (en) | 2009-12-17 | 2011-07-14 | Prüftech GmbH | Self-monitoring connection line and operating equipment |
| US9470730B2 (en) | 2009-12-17 | 2016-10-18 | Pruftech Gmbh | Self-monitoring power supply cord and operating equipment |
| GB2499514A (en) * | 2012-02-14 | 2013-08-21 | Geoffrey Irish | Testing a ring main circuit using a switchable test arrangement e.g. in a wall socket |
| GB2499514B (en) * | 2012-02-14 | 2014-10-08 | Geoffrey Irish | Electrical connector |
| GB2506669A (en) * | 2012-10-07 | 2014-04-09 | John Paul Wasellas | Socket outlet unit including ring main circuit conductor separating means |
| GB2506669B (en) * | 2012-10-07 | 2017-09-20 | 810 Innovation Ltd | Socket outlet including ring final circuit conductor separating means |
| WO2024010511A1 (en) * | 2022-07-06 | 2024-01-11 | Megger Sweden Ab | Method, assembly and sense unit for measuring the frequency response of a plurality of electrical objects |
Also Published As
| Publication number | Publication date |
|---|---|
| SI22426A (en) | 2008-06-30 |
| GB2444850B (en) | 2010-01-06 |
| GB0724265D0 (en) | 2008-01-23 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20211212 |