CHECKING AND TESTING ELECTRICAL INSTALLING WORK

CHECKING AND TESTING ELECTRICAL INSTALLING WORK Department of Consumer and Employment Protection Energy Safety

Preface It is a requirement of the Electricity (Licensing) Regulations 1991 that all electrical installing work carried out in Western Australia complies with the relevant standards, including Australian/New Zealand Standard AS/NZS 3000 (known as the Wiring Rules) and the WA Electrical Requirements. The application of minimum electrical requirements and Standards is essential for the safety of persons, livestock and property. A clear understanding of these requirements is essential for those involved with electrical installing work carried out in Western Australia. All completed electrical work must be checked and tested by a licensed electrician before the electrical contractor certifies the work to the relevant supply authority. This booklet has been produced as a guide to meet the checking and testing requirements for electrical installing work, as specified in the Wiring Rules. Whilst the details are focussed on domestic electrical installations, the principles apply to all electrical installing work. The testing methods in this booklet are not exclusive. Other test methods may be used provided that they meet the minimum requirements of the Wiring Rules. More detailed testing information is contained in the Australian/New Zealand Standard AS/NZS 3017 Electrical installations - Testing and inspection guidelines.

Table of Contents Checking, Testing and Certification of Electrical Installing Work 1 Installation Test Certificate 2 Checking and Testing 4 Checking and Testing Procedure 5 1. Visual Inspection 5 2. Earth Resistance and Continuity Tests 5 Test Equipment 6 Test Procedure 7 3. Insulation Resistance Test 8 Test Equipment 8 Test Procedure 8 4. Polarity/Functional Test 10 Test Equipment 10 Test Procedure 10 5. Correct Circuit Connections 11 6. Fault-loop Impedance Test 11 Test Equipment 11 Test Procedure 11 7. Verification of RCD 12 Testing Alterations and Additions 12 Test Equipment 13 Table 1 - Maximum resistance values of final subcircuit 14 protective earthing conductor Table 2 - Comparison of voltage drop and fault-loop 15 impedance to determine circuit maximum distance. Further Information 16 Notes 17

IV CHECKING AND TESTING ELECTRICAL INSTALLING WORK

Checking, Testing and Certification of Electrical Installing Work All completed electrical installing work must be checked and tested to confirm that it complies with the Wiring Rules and is safe for connection to the electricity supply. The required steps to comply with the current regulatory requirements are as follows: 1. When the electrical installing work has been completed, a licensed electrician (which may be the contractor or an employee) is required to carry out checks and tests of the installation, to ensure the electrical work meets the requirements of the Wiring Rules. The checking and testing should be carried out in accordance with a formalised checking and testing procedure. 2. Once these checks and tests have been completed, the electrician confirms on the relevant section of the Notice of Completion or Notice of Completion- Minor Work, that the checking and testing has been carried out. 3. For electrical installing work that requires the supply authority to attend (eg. for electricity supply connection or alteration to the supply service apparatus), the electrician then completes an Installation Test Certificate and fixes it inside the meter enclosure of the installation. 4. Then, in the usual manner, the electrical contractor (or nominee) completes the Notice of Completion, thereby certifying the work, and submits the Notice to the supply authority. 5. When the Notice of Completion is received, the supply authority will determine if an inspection of the installing work will be carried out, to ensure that the standards of electrical safety of the installation are being maintained. The supply authority will also arrange for the connection of the electricity supply if necessary. Notes 1. Minor work, ie. alterations and additions to existing electrical installations, is also subject to a similar system except that the work is connected to the electricity supply by the electrician. 2. Western Power s Contractor Connect Scheme permits accredited electrical contractors and authorised electrical workers to connect the electricity supply to the installation and to then submit the Notice of Completion following connection. 1

Installation Test Certificate When a Notice of Completion is to be submitted for completed electrical installing work that may require the supply authority to attend (eg. new connection or upgrade of supply), the electrician carrying out the checking and testing must complete an Installation Test Certificate. An Installation Test Certificate is an adhesive label (included in books of Preliminary Notices/Notices of Completion and also available from supply authorities) that must be filled in by the electrician who performed the checking and testing of the completed electrical installing work. An Installation Test Certificate is to be fixed by the electrician to the inside of the meter enclosure to indicate to the supply authority and the customer that the installation is completed, has been checked and tested and is safe to be connected to the electricity supply. The electrician is requested to record the following key installation test results and the underground consumer s mains cable route on a self adhesive label which is also to be placed inside the meter enclosure: main earth conductor resistance; either the earth continuity or fault-loop impedance values for each sub circuit; and insulation resistance values for each sub circuit. The information will benefit subsequent electrical work and inspection, as well as assist in preventing electric shocks and accidents. 2

INSTALLATION TEST CERTIFICATE Installation Address: I confirm that I have carried out the checks and tests of this electrical installation, as required by Electricity (Licensing) Regulations 1991. Signature of A Grade Electrical mechanic Date E.W. Licence No This work has been carried out for and on behalf of: Electrical contractor s name and licence No. Note 1. The Electrical Mechanic is responsible for the issue of this Test Certificate. 2. This Test Certificate is to be fixed to the inside of the meter enclosure. DON T MEDDLE WITH ELECTRICITY - ALWAYS USE A LICENSED ELECTRICAL CONTRACTOR 3

Checking and Testing On completion of the electrical work and before the electricity supply is connected and energised, the electrical contractor is responsible to ensure that: the electrical work has been carried out in accordance with the Electricity (Licensing) Regulations 1991; and the installation has been checked and tested and is safe for connection to the electricity supply. To achieve this, the following minimum checks and tests should be carried out by the electrician: 1. Visual Inspection - should be carried out whilst referring to a plan (to ensure a systematic check to pick up any omissions and to verify that the work complies with the requirements of the applicable standards). 2. Earth Resistance and Continuity Tests - this test is to include the main earthing conductor, protective earth conductor and bonding conductor. 3. Insulation Resistance Test - this test is necessary to ensure that the insulation resistance between live parts/conductors and earth is adequate. 4. Polarity Test - used to ensure correct connection of active, neutral and earthing conductors. 5. Correct circuit connections - this test checks earthing conductors do not carry current during normal operation and no short circuit exists. 6. Fault Loop Impedance - measures the fault loop impedance of each circuit to verify the protective device will operate. 7. Verification of RCD (residual current device) operation - testing of RCDs is carried out to ensure that the RCD operates. 4

Checking and Testing Procedure The following procedure will meet the key checking and testing requirements. Ensure that test results are recorded carefully. Other testing procedures may be used, provided that they meet the minimum requirements of the Wiring Rules. It is also recommended that the tests be carried out whilst there is no electricity supply connected (except for the Fault Loop Impedance verification or the RCD operation test) to the installation, or, in the case of alterations to an existing installation, that the circuits to be tested have been isolated from the electricity supply and have been securely tagged and where possible padlocked. 1. Visual Inspection A visual inspection is carried out to ensure that all work has been correctly completed, by checking that: all cables and equipment have been correctly installed and terminated, and the installation complies with the relevant parts of the Wiring Rules and the WA Electrical Requirements. 2. Earth Resistance and Continuity Tests Earth resistance tests are required to confirm the installed earthing system will cause circuit protective devices to operate and maintain cable integrity if there is a fault between live parts and exposed conductive parts. Earthing System Impedance The resistance from any point of the electrical installation required to be earthed, to the point where the main earthing conductor is connected to the neutral conductor (MEN connection) of the supply system, shall be low enough to permit the passage of current necessary to operate the circuit protective devices. To confirm this value (which is dependent upon the type and rating of the protective device and the fault-loop impedance of the associated conductors) requires the following test to be performed: Test 1: Obtain the resistance value of the protective earthing conductor using a quality ohm meter (see next page for procedure) and compare this value with the maximum allowable resistance as tabulated in Table 1, page 14 of this booklet. 5

Or, where the electricity supply IS connected: Test 2: Obtain the fault-loop impedance of each sub circuit using a quality faultloop impedance meter (refer to manufacturer s instructions and page 11 of this booklet for procedure). Compare the measured fault-loop impedance value with the maximum value provided at Appendix B, Table B4.1 of the Wiring Rules. Notes: 1 If the application of a fault-loop impedance test onto an RCD protected sub circuit results in the RCD operating, then: the earth resistance and continuity test requirements are considered to be satisfied; and the fault-loop impedance value need not be considered further. 2 If the value measured is GREATER than the allowable maximum, then the following steps must be performed: Test 2.1 Check the MEN connection, active, neutral and earth conductor/equipment connections are all solidly made. Repeat the fault-loop impedance test 2, above. If the fault-loop impedance values exceed the requirements of Table B4.1, then perform Test 2.2 Test 2.2 Perform the earth continuity measurement, Test 1 and confirm results. Repeat the fault-loop impedance Test 2, above. If the fault-loop impedance values do not satisfy the requirements of Table B4.1 then you must contact the supply authority advising them of the discrepancy. Main Earthing Conductor The resistance from the earthing electrode to the point where the main earthing conductor is connected to the neutral conductor of the supply system shall not exceed 0.5 ohms. Test Equipment A multimeter set to ohms. Insulated copper conductor of suitable length (long lead). 6

Test Procedure Preparation: 1. Ensure that the electricity supply has been disconnected. 2. Connect an insulated copper conductor of suitable length (long lead) to one terminal of the ohm meter. 3. Connect a standard length test lead to the other terminal of the ohm meter (short lead). 4. Connect the two leads together, and zero the multimeter or, if this is not possible, record the resistance of the test leads. 5. Disconnect the water pipe equipotential bonding conductor and the water heater earthing conductor (if applicable). Care must be taken that there are no parallel earth paths when conducting this test, ie. the earthing system must not be connected to either the water or gas pipes. 6. Disconnect the MEN link from the main neutral link and connect it to the long lead (ie. long lead now connected to the earth bar). A: Main Earthing Conductor Connect the short lead to the earth electrode and measure the earth resistance of the main earthing conductor. The resistance shall not exceed 0.5 ohms for the main earthing conductor. B: Earth Continuity Test Using the long lead and zeroed multimeter, measure, for each circuit, the earth conductor resistance from the circuit extremity to the switchboard. Confirm the measured values are LESS THAN those values as provided at Table 1, page 14 of this booklet for each sub circuit. This test is applicable to all circuits, including socket outlet circuits, lighting circuits and fixed equipment (eg. water heater supply) circuits. 7. Re-connect the MEN link to the main neutral link. 8. Re-connect the water pipe equipotential bonding conductor. 7

3. Insulation Resistance Test An insulation resistance test is performed to ensure that the resistance between all live conductors and earth, or as the case maybe, all live parts and earth, is adequate to prevent electric shock hazards, fire hazards and equipment damage. It is a requirement of Clause 6.3.3.3.1 of the Wiring Rules that the insulation resistance between all live conductors (including the neutral) connected together, and earth, measured with all protective devices in circuit and all switches on, is not less than 1 Megohm (see Note below). This applies to the complete installation and all parts of the installation. This does not preclude the use of appliances incorporating heating elements provided that, when tested with all elements in circuit, the insulation resistance between live parts and the earthing terminal or earthing contact of the appliance is not less than 0.01 Megohm (10,000 ohms). Note: Whilst the minimum reading is 1 Megohm, the ideal reading is infinity. This indicates a sound installation. Test Equipment Where the supply voltage does not exceed 250 volts between conductors and earth, a 500 volt insulation tester should be used to perform this test. Test Procedure 1. Ensure that all protective devices are in circuit and that all switches are on. If there are two way lighting circuits in the installation, tests must be carried out with the two way switches in all positions, so all circuit conductors are tested. 2. Set the insulation tester (eg. Megger) to Megohms. 3. Connect one lead of the insulation tester to the main earthing bar (MEN Link disconnected) and the other lead to the actives and neutrals connected together. Do not test between actives and neutrals. 4. Measure the insulation resistance of the total installation (including the consumers mains). If the insulation resistance is 1 Megohm or more - re-connect the MEN Link and return the installation to normal. 8

If the insulation resistance is less than 1 Megohm - test all circuits individually, starting with circuits supplying appliances incorporating heating elements. Where a circuit is less than 1 Megohm, disconnect the appliance or appliances. Then test the circuit and appliance (separately) to ensure that the insulation resistance of both the circuit and the appliance complies with the following: not containing a heating element - is not less than 1 Megohm, or containing a heating element - is not less than 0.01 Megohm Note: Where the insulation resistance of an appliance containing heating elements is found to be less than 0.01 Megohm and the defect cannot be rectified at the time of checking and testing, the electrical contractor must make arrangements for correction of the defect prior to submission of the Notice of Completion. Alternatively, the following procedure may be used: a) Isolate the defective circuit, including the neutral conductor, by disconnecting at the appropriate switchboard. b) Attach an out of service tag to the circuit protection device, advising that the circuit has been disconnected due to low insulation resistance. c) Check that the earth conductor has been reconnected at the MEN point. d) Then submit the Notice of Completion. Ensure that all circuits and the MEN connection are re-connected when the testing is complete. 9

4. Polarity Test Polarity tests are carried out to ensure the correct connection of active, neutral and earth conductors to electrical equipment and to ensure that switches are not installed in neutral conductors. Clause 6.3.3.4 Polarity of the Wiring Rules specifies the testing requirements for this mandatory test. Test Equipment To carry out these tests, a continuity tester such as a multimeter (set to ohms) should be used. Test Procedure To ensure that the installation circuits/equipment will function as intended, it is necessary that the following tests be performed: Isolate the active conductors by turning the main switch OFF and tagging. Confirm consumer and sub mains cables/connections by simply testing from the point of supply or distribution board to the main switchboard using an ohm meter and long test loads. Test result 0 Ω. Confirm active conductor switching by using an ohm meter with the long lead connected to the active conductor at the switchboard and the short lead connected to the switch terminals (one at a time) in the following manner: i) Switch ON 0 Ω for both terminals ii) Switch OFF 0 Ω for one terminal and infinity for the other terminal With the MEN link in place, confirm the polarity of socket outlets using a 10Ω resistor and an ohm meter. Connect the 10Ω resistor between the circuit active conductor and the neutral bar then at each socket outlet connect one lead of the multimeter to the earth terminal and the second lead to the active terminal. Test the resistance value for: i) socket outlet switch OFF infinity ii) socket outlet switch ON 10Ω. 10

5. Correct Circuit Connections These tests are required to ensure the following: 1. that protective earthing conductors do not carry current; 2. to prove there are no short circuits within the installation; and 3. for the circuit continuity test to prove each circuit for electrical continuity and that all switches operate in the active conductors. 6. Fault-loop Impedance Test This test is carried out to confirm the fault-loop impedance value of each circuit will be low enough to ensure the operation of the protective device during a fault. Test Equipment To perform the fault-loop impedance test, a fault-loop impedance meter is required. Test Procedure Energise all circuits Using the fault-loop impedance meter, proceed to the equipment to be tested and measure the earth-loop impedance at this point. Repeat for other items on the circuit. The measured value must be less than the maximum values as tabulated at Table B4.1 of the Wiring Rules. If an RCD operates during the test, the test result can be considered satisfactory. 11

7. Verification of RCD Operation This is normally achieved by operation of the integral test device (typically test button on the RCD) to confirm: 1. the RCD is functioning correctly; and 2. the tripping device mechanisms are operating. Warning: Operation of the integral test device does not provide a means of checking: continuity of the main earthing conductor or the associated circuit protective earthing conductor; or any earth electrode or other means of earthing or the associated electrical installation earthing. Testing Alterations and Additions When alterations are carried out to an existing electrical installation, it is essential that the electrician tests the work to ensure compliance with the relevant standards and specifications. The tests described in this booklet must also be carried out on alterations and additions to ensure the electrical installing work is safe to remain connected to the electrical installation. The majority of tests described in this booklet are designed to be carried out without power being connected. When performing these tests, make sure that electricity supplies are disconnected where necessary and that the appropriate isolation and tagging has been carried out. A Notice of Completion form must be submitted to the supply authority to certify this type of work. 12

Test Equipment Before performing any tests, ensure that the test equipment is correctly set, is functional and is in good condition, particularly the test leads. Remember, when testing: check that the test equipment is operating correctly perform the required tests re-check the test equipment to confirm that it still operates correctly. Some types of test equipment (eg. multimeters) are fitted with fuse protection. Ensure that at all times only the correct type and rated fuse is used. This is for your protection. Electrical test equipment is a very important part of an electrician s tools. Test instruments should be tested at intervals not exceeding one year and records kept to verify this. 13

Table 1 Maximum resistance values of final sub circuit protective earthing conductors Protective Circuit - breakers Type B Type C Type D Fuses Device Earthing Disconnection times Rating Conductor Size 0.4sec 0.4sec A mm 2 Maximum final subcircuit earth conductor resistance Ω 6 1 3.08 1.65 1.00 3.69 10 1.5 1.85 1.00 0.60 2.06 16 2.5 1.16 0.62 0.38 0.99 20 2.5 0.93 0.50 0.30 0.68 25 2.5 1.07 0.57 0.34 0.76 32 2.5 0.72 0.38 0.23 0.51 40 2.5 0.66 0.35 0.21 0.44 50 4 0.54 0.29 0.17 0.34 63 6 0.44 0.23 0.14 0.26 14

Table 2 Comparison of voltage drop and fault-loop impedance to determine circuit maximum distance This table details the single phase voltage drop for a combination of conductor size, maximum demand current and distance. It also displays the maximum circuit length for a Type C circuit breaker (as normally used in most installations) to ensure the operation of the circuit breaker during an earth fault. You will notice that compliance for voltage drop is the predominant requirement compared to the fault-loop distance for the given circuit breaker type. Conductor Size Protective Device Rating Maximum Demand Distance 20m 30m 40m 60m 80m Voltage Drop Maximum Distance m For Voltage Drop #2 For Type C Circuit Breaker #3 mm 2 A A #1 V (11.5V = maximum) 1.0 10 10 10.3 - - - - 22* 55 5 5.2 7.7 10.3 - - 45* 55 1.5 10 10 6.6 9.9 - - - 35* 82 5 3.3 5.5 6.6 9.9-70* 82 2.5 16 16 5.8 8.6 - - - 40* 85 8 2.9 4.3 5.8 8.6-80* 85 4.0 25 * Denotes limiting parameter 25 5.6 8.4 11.2 - - 41* 67 12.5 2.8 4.2 5.6 8.4 10.2 82 67* Notes: #1: Maximum demand determined using (a) full load, and (b) half the rating of the protective device assuming distributed load. Refer to Wiring Rules Clause 3.6.2 #2: Voltage drop determined using 230V @ 5% = 11.5V maximum allowable. #3: Distances obtained from Wiring Rules table B5.1. 15

Further Information For further information on testing electrical installing work, please contact the Electrical Inspector at the relevant supply authority, as listed in the manual WA Electrical Requirements. For further information, please contact: ENERGY SAFETY 20 Southport Street WEST LEEDERVILLE WA 6007 Telephone: 08 9422 5200 Facsimile: 08 9422 5244 Email: energysafety@docep.wa.gov.au Website: www.energysafety.wa.gov.au 16

Department of Consumer and Employment Protection Issued by Energy Safety 20 Southport Street West Leederville WA 6007 Telephone: (08) 9422 5200 Facsimile: (08) 9422 5244 Email: energysafety@docep.wa.gov.au Website: www.energysafety.wa.gov.au ESWA E022 0104