S.D.F Electrical Pty Ltd QLD. LICENSE NO ABN PROCEDURE

Transcription

1 OBJECTIVE To detail the electrical tests that shall be completed before and after electrical installation work is connected to supply. This testing procedure can be used for the testing of new installations or a full electrical test on an existing installation. LEGISLATION (Ref S36 & S37 of Electrical Safety Act QLD) A person who installs electrical equipment or an electrical installation has an obligation to ensure that: - (a) (b) (c) the way the electrical equipment or installation is installed is electrically safe; the processes followed for installing the electrical equipment or installation, when installed, will be electrically safe; after the electrical equipment or installation is installed, the person tests and examines it to ensure it is electrically safe. Obligation of repairer of electrical equipment or electrical installation 1. A person who repairs electrical equipment or an electrical installation has an obligation to ensure that: - (a) (b) (c) the way the electrical equipment or installation is repaired is electrically safe; the processes followed for repairing the electrical equipment or installation, whilst performing the repair, are electrically safe; and the electrical equipment or installation, when repaired, is electrically safe. 2. Without limiting subsection (1), the obligation includes ensuring that the electrical equipment or installation, when repaired, is tested and examined to ensure it is electrically safe. Review Date: Page 1 of 13

2 Each of these Gates MUST be cleared before proceeding to the next step S.D.F Electrical Pty Ltd Are you a licensed Electrical Worker? No DO NOT PROCEED Yes Gate No 1 Have you been authorised to test by the Technical Endorsee? No Do not proceed until you have been authorised to test by the Technical Endorsee Gate No 2 Yes Will you be using test equipment from the S.D.F. Electrical test equipment register? No Do not use test equipment that is not on the Test Equipment Register Gate No 3 Yes Have you carried out a functional test on the test equipment just prior to testing? No Do not proceed with testing until test equipment operation has been validated (AS/NZS 3017) Gate No 4 Yes Have you signed on to the Testing Safe Work Method Statement? No Do not proceed with testing until you have completed the Safe Work Method Statement - sign off record Gate No 5 Yes PROCEED TO NEXT PAGE Review Date: Page 2 of 13

3 1. METHOD This procedure is derived from AS/NZS 3000:2007, AS/NZS 3017:2007 and the Electrical Safety Regulations It has been arranged so that testing and checking may be carried out in a logical and orderly manner. However, it is acceptable to vary the written procedure providing; the same results are achieved, the intent of the procedure is satisfied and the installation is electrically safe. The inspection process should be results orientated and not necessarily procedural orientated PERQUISITE PRIOR TO CARRYING OUT TESTING (GATE 1 & GATE 2) Before performing any Mandatory Tests prescribed by AS/NZS 3000, testing personnel SHALL have an Authorised Person card as shown below. To obtain an Authorised Person card, the Technical Endorsee for S.D.F Electrical shall assess the competency of the Electrical Worker. If the Electrical Worker is deemed competent to perform electrical testing, an Authorised Person card will be issued to the individual and a record of the endorsement shall be kept on the Staff Register available on SharePoint. Authorised Person Card 1.2. TEST EQUIPENT (GATE 3 & GATE 4) Only test equipment which is registered on SDF Electricals test equipment register is permitted to be used for electrical testing. Prior to performing any mandatory tests, the test equipment shall be verified it is in correct working order. Refer to: SDF-05 -Testing of electrical instruments and SDF-06 - Before use inspection of test instruments WORK METHOD STATEMENT (GATE 5) Prior to commencing any work, all workers shall: be signed onto the appropriate work method statement Complete a Risk Assessment Check Sheet - Form 4(a) and Complete a Risk Assessment Form 33 making sure all hazards and risks are identified and that all controls are in place before testing. Review Date: Page 3 of 13

4 2. S & TEST RESULTS S.D.F Electrical Pty Ltd 2.1. TEST RESULTS Electrical tests results shall be recorded on Form 4 Electrical Test Sheet. If it is necessary to provide a written report to the customer in the case of faults or abnormalities in the Electrical Installation, use Form 14 Electrical Safety Report. NOTE: All columns on test sheet FORM 4 must be filled in. If a reading not required indicate with N/A PRIOR TO TESTING 1. Advise the customer that it is necessary to disconnect the supply. 2. Note the position of protective devices as to whether any are isolated. Leave installation in condition as it was found. 3. If supply is connected isolate supply at the appropriate point. Disconnect any earth bond to the neutral when there is an aerial supply MANDATORY TESTS/REQUIREMENTS The following tests shall be carried out on all electrical equipment and installations prior to energization: Visual inspection (Mandatory requirement) Continuity of earthing system Insulation resistance Polarity Correct circuit connections Fault loop impedance Operation of RCD Visual Inspection A visual examination of the electrical installation shall be conducted to ensure that the electrical work is complete and that all cables are properly terminated in the correct terminals. Conduct a visual inspection of the installation using Form 5 - Visual Inspection Check Sheet Earthing Continuity The resistance of protective earthing conductors shall be: a) low enough to permit the passage of current necessary to operate the overcurrent protective device; and b) consistent with the length, cross-sectional area and type of conductor material, e.g. for a 100 metre length of 2.5mm2 copper conductor, a resistance of 0.8 Ω could be expected. The resistance of the main earthing conductor or any equipotential bonding conductor shall be not more than 0.5 Ω. Definitions: 1. A main earthing conductor and a protective earthing conductor carries any return or fault current. 2. A bonding or equipotential conductor is to ensure all metal of the installation is at the same potential. Review Date: Page 4 of 13

5 Testing Procedure 1. Remove the main earthing conductor and the main neutral conductor from the neutral link. Where practicable, disconnect any earth bond conductor (e.g. water heater earth, water pipe bond and reinforcing bonds). 2. Test continuity of the main earthing conductor between the electrode adjacent to the main earth connection and the main switchboard. Maximum Resistance Test continuity between the main earthing conductor at the switchboard and any portion of metallic water piping and wet area reinforcing steel required to be bonded, i.e. any copper water pipe leaving the ground and entering the building. Maximum Resistance Test continuity between the main earthing conductor at the switchboard, all accessories and permanently connected appliances that are required to be earthed e.g. HWS, socket outlets, lights, motors, range, etc. 5. Record results. Confirm results are within acceptable limits. 6. Make corrections and re-test as necessary. 7. Reconnect any earth bonds that were disconnected. NOTE 1: If insulation resistance tests are carried out before continuity tests a defective continuity test may require a further insulation resistance test of the circuit affected. NOTE 2 Confirmation of earth continuity using tables in Section may not constitute conformance for fault loop impedance requirements. Refer to Section Test Results Record the value of resistance in the appropriate field of Form 4. a) Where active and earth conductors are connected at the end of circuit and resistance measured at start of circuit, use Table 1 to verify measured resistance is less than or equal to the expected value. b) Where trailing lead & zeroed low ohm meter is used to measure resistance of protective earth, use Table 2 to verify measured resistance is less than or equal to the expected value TABLE 1 Active Conductor 1mm 1.5mm 2.5mm² 4mm² 6mm² 10mm² Earth Conductor 1mm 1.5mm 2.5mm² 2.5mm² 2.5mm² 4mm² Length (m) Table 1 - Expected resistance values of circuit where active and earth conductors are connected at end of circuit and resistance measured at start of circuit Review Date: Page 5 of 13

6 TABLE 2 Earth Conductor 1mm 1.5mm 2.5mm² 4mm² 6mm² 10mm² Length (m) Table 2 - Expected resistance values of circuit where trailing lead with zeroed low ohm meter is used to measure resistance of protective earth Insulation Resistance An insulation resistance test is necessary to ensure that the insulation resistance between all live conductors and earth or, as the case may be, all live parts and earth is adequate to ensure the integrity of the insulation Testing Procedure 1. Test insulation resistance between the main earthing conductor at the switchboard and each conductor of the consumer s mains. 2. Test insulation resistance between active and neutral conductors of consumer s mains (between phases if three phase), sub-mains and final sub circuits. Ensure that parallel conductors have no interconnection. 3. Test insulation resistance between the main earthing conductor at the switchboard and the neutral link and terminals of the main switch/s. 4. Where circuits with low insulation resistance incorporate appliances, disconnected the appliance where practical and repeat the test to establish whether the appliance or the circuit has the low insulation resistance. 5. Test insulation resistance between any conductive parts of low pitched rooves or rooves associated with cathedral ceilings and the main neutral link and the terminals of the main switch/s. Minimum Insulation Resistance 1 m Test Results Record the value of resistance in the appropriate field of Form 4 and verify actual readings are satisfactory. Element Consumers Mains General Installation General appliances incorporating heating elements Minimum Insulation Resistance 1m 1m 0.01m Review Date: Page 6 of 13

7 Polarity Testing Polarity Testing of Mains S.D.F Electrical Pty Ltd 1. Turn OFF the main switch/s and any circuit breakers or remove all fuse carriers. Confirm that bonding conductor to a service support is not connected and that main neutral is still disconnected from link. NOTE: These tests may also be achieved using a low reading ohmmeter and a trailing lead, testing end to end of each conductor and making sure each conductor is in its correct terminal. 2. Reconnect supply. 3. Test between the main neutral conductor and the line terminal/s of the main switch/s and on a multiphase installation, between phases. The test lamps should light, proving that the test lamps are in order and that the required supply is available. 4. Test between the main neutral conductor and an independent earth electrode. The test lamps should not light. 5. Test between an independent earth electrode and the line terminal/s of main switch/s. The test lamps should light. NOTE: Failure of the test lamps to light during this test indicates that the resistance between the independent electrode and the general mass of earth is too high. The last two tests must be repeated using an approved instrument (voltmeter) in lieu of test lamps. 6. Test between the main neutral conductor and both line and load side of all circuit protective devices. The test lamps should not light, proving there is no supply at the circuit protective devices with the main switch/s in the "OFF" position. 7. Replace the main neutral conductor and main earthing conductor into the neutral link. 8. Turn the main switch ON. NOTE 1: A similar polarity test sequence is required for sub-mains. NOTE 2: Replacement of the main earth and neutral into the neutral link at this time is to minimise the possibility of a potential rise on the earthing system during tests and causing others on site to receive a shock. 9. Test between the main neutral conductor and the line side of all circuit protective devices (CPDs) proves supply at CPDs. 10. Test between the phases of circuit protective devices on a multiphase installation. 11. Test between the main neutral conductor and the load side of any circuit breakers. Test lamps should not light proving the CBs turn off. 12. Reinstate any service bonding conductor that was removed. Polarity testing of final sub-circuits 1. Test the switch, isolator or other switching device operates the active conductor/s on all light and power devices. 2. Test for polarity on all multi switched light circuits. Testing of phase sequence Phase sequence testing is necessary to ensure that multi-phase equipment such as multi-phase motors and semiconductor controlled equipment operates in a predictable manner. 1. When supply is available, use a phase sequence tester in accordance with the manufacturer s instructions. Review Date: Page 7 of 13

8 2. When supply is not available, test using a multimeter and a trailing lead to each pin of the 3 phase outlet to the source of the final sub-circuit. Note: Each 3 phase outlet must be tested and be the same sequence for all Earth Fault Loop Impedance The impedance of the earthing system shall be limited to that which will generate sufficient current in the protective device to cause operation of that device within the required time Non RCD Protected Circuits Supply Connected 1. Use a Fault Loop Impedance Tester to measure the earth fault-loop impedance of a circuit. The reading shall be taken from the farthest point from the protective device. NOTE: This is regarded as a live test. 2. Record the value of impedance in the appropriate field of Form 4 and verify the reading is satisfactory. Refer to AS3000 Table 8.1 for maximum values of fault loop impedance. Supply Not Connected 1. Join the active and corresponding earth conductors of the circuit at the protective device end. 2. Use a multimeter to measure the resistance of the 2 conductors at the farthest point of the circuit. 3. Record the value of resistance in the appropriate field of Form 4 and verify the reading is satisfactory. Refer to AS3000 Table 8.2 for maximum values of R phe RCD Protected Circuits Fault Loop Impedance need not be carried out on an RCD protected sub-circuit however Fault loop impedance should be verified on mains and sub-mains where earth leakage protection is installed Residual Current Device (RCD) Operation Test 1. Test the integrity of the RCD function by tripping the device with the test button. 2. Test the device by using an RCD Tester and note the time taken to disconnect the supply. On a 30mA RCD this time must be less than 300mS. NOTE: This test is regarded as a live test SUPPLEMENTARY TESTS & CHECKS Verification of Supply Voltage 1. Measure voltage at the point of supply to ensure it meets the requirements of AS3000:2007 s.1.6.2(c) as shown below: a. For single phase 216V 253V b. For three Phase 376V 440V 2. If voltage is more or less than the above, recommend to the customer that they request the electricity distributor to conduct a voltage check at their terminals Verification of Installation 1. Check marking and rating of main switch/s is correct and refit neutral link cover where required. 2. Test with the whole of the installation energised, including lighting points switched ON, that any exposed conductive parts are not live. 3. Ensure any fridge, freezer or hot water system is energised and stove elements and oven are off. Review Date: Page 8 of 13

9 4. Before leaving the site check that the switchboard is in the same condition as it was found. Ensure any fridges, deep freezes or hot plate elements are in the same electrical position (i.e. on or off) as when you found them. 5. Recheck the MEN connection 2.5. EQUIPMENT SPECIFIC S Water Heater 1. Energise circuit. 2. Check that the control switch, over temperature cut-out and thermostat are connected in the active conductor. 3. Check that the neutral conductor corresponds with the active conductor and that there is no interconnection with other circuits. 4. Check access is available for component replacement and maintenance. 5. Check circuit loading and that the current carrying capacity of the cable, control switches, and protection device has not been exceeded and the switchboard is correctly marked. For water heaters with off peak and booster elements that have a common neutral, a double pole control switch or double pole circuit breaker is required Range/Cooking Appliance 1. Ensure that any isolating switch and all range element control switches are in the "OFF" position. NOTE: kw rating of range and check the current carrying capacity of all cables and equipment forming part of the final sub-circuit for the range has not been exceeded. 2. Connect supply and prove that any isolating switch is connected in the active conductor and effectively isolates supply. If fuses are incorporated in the range prove they are connected in the active conductor. 3. Check that the neutral conductor corresponds with the active and that there is no interconnection with other circuits. 4. Any cooking appliance connected by a 20Amp or less socket outlet protected by an RCD, the RCD must be tested for operation and accuracy Power Circuits 1. Energise and test one circuit at a time, checking each outlet individually for continuity polarisation and polarity. For socket outlets 20Amp rating or less not protected by RCD, test the last most extreme outlet on the circuit for loop impedance reading using a loop impedance tester having regard to maximum readings set out in AS/NZS 3000:2007 Table Alternatively, these tests can be carried out with power off using a low reading ohmmeter and the loop impedance phase/earth reading having regard to AS/NZS 3000:2007 Table Energise the RCD/s and test for accuracy with an RCD test instrument. The RCD/s should trip between 50% and 100% of rated value. 4. Energise all applicable circuits and press any RCD test button to ensure it is operational. 5. Check cable rating, RCD current and trip rating, fuse element or circuit breaker size and switchboard marking Lighting Circuits 1. Energise each lighting circuit separately. Check that each light works. A light connected by a plug and socket is not regarded as a socket outlet. Review Date: Page 9 of 13

10 2. Test light switches for correct polarity and two/three-way operation. 3. Energise the RCD/s and test for accuracy with an RCD test instrument. The RCD/s should trip between 50% and 100% of rated value. 4. Test RCD operates correctly by initiating push button test. 5. Check cable rating, fuse element or circuit breaker size and switchboard marking Permanently Connected Appliances or Equipment 1. Energise each circuit separately. 2. Check the circuit protection device does not exceed the current carrying capacity of the conductor. 3. For socket outlets energise and test one circuit at a time. Where the circuit is not RCD protected check the furthest socket outlet for verification of Fault Loop Impedance using the maximum readings of Table 8.1 AS/NZS 3000:2007 alternatively when supply is not available the combined active-earth resistance using the maximum readings of Table 8.2 AS/NZS 3000: Energise the RCD/s and test for accuracy with an RCD test instrument. The RCD/s should trip between 50% and 100% of rated value. 5. Energise any RCD/s that may be associated with permanently connected appliances (eg. pool equipment, wall ovens etc) and test for accuracy with an RCD test instrument. Initial any push button to check its operation Energising Switchboards Prior to the initial energisation of any switchboard, SDF-FORM-ENG-09 ELECTRICAL PRE- ENERGISATION CHECKLIST shall be completed for the switchboard. All Test Sheets shall be presented to the Supervisor for verification. The supervisor shall ensure that the all tests have been satisfactorily completed and documented. NOTE: Initial energisation requires the explicit approval of the supervisor and is a mandatory SDF requirement PERSONAL PROTECTIVE EQUIPMENT On the rare occasion that that live electrical work is required, the risks assessment for the live work MUST also consider the exposure the Electrical Worker has to the potential fault current available. Table 9.2 below is an extract from AS/NZS 4836 that provides guidance on the PPE associated with the level of fault current. Table 9.2 and indeed AS/NZS 4836 in its entirety must be complied with when working live or on/near live electrical parts. A copy of AS/NZS 4836 is always available on SharePoint RELATED POLICY & S: Working Live Policy Electrical safety obligations Procedure SDF-01 Work process flowchart Procedure SDF-02 Testing of electrical instruments Procedure SDF-05 Before use inspection of test instruments Procedure SDF-06 Safety tag and lock-out Procedure SDF-09 SDF-FORM-ENG-09 ELECTRICAL PRE-ENERGISATION CHECKLIST Review Date: Page 10 of 13

11 1 Work (isolated and verified) 2 3 S.D.F Electrical Pty Ltd AS/NZS TABLE 9.2 GUIDE TO THE SELECTION OF PERSONAL PROTECTIVE EQUIPMENT TASK CURRENT UP 100 A CURRENT EXCEEDING 100 A UP TO 400A CURRENT > 400A A B C D Switching, isolating, removing fuses or links Isolation verification, testing or fault finding Protective clothing (if required) (if required) Gloves (if required) Protective clothing Gloves (if required) Protective clothing Gloves 4 Live electrical work Protective clothing* Insulating gloves Arc flash suit and hood (if required) Flame-resistant gloves (if required) Face shield (if required) (if required) : Determined by the risk assessment. * Collar up, top buttons done up and sleeves down. Protective clothing (if required) (if required) Gloves (if required) Protective clothing Gloves Protective clothing* Gloves Arc flash suit and hood (if required) Face shield (if required) Protective clothing * Safety helmet Insulating gloves Arc flash suit and hood (if required) Flame-resistant gloves (if required) Face shield (if required) Protective clothing (if required) (if required) Gloves (if required) Protective clothing Gloves Protective clothing* Gloves Face shield Arc flash suit and hood (if required) Protective clothing * Insulating gloves Flame-resistant gloves Arc flash suit and hood Hearing protection Bracelets, rings, neck chains, exposed metal zips, watches, and other conductive items shall not be worn while working on or near exposed energized conductors or live conductive parts. Review Date: Page 11 of 13

12 SIGN OFF RECORD Electrical Worker in Charge By signing this, I acknowledge that I am aware of and agree with the procedure described in this document. I agree to see that I will ensure this procedure will be properly implemented and maintained. I will communicate the contents and interpretation of this procedure to each applicable member of the work crew and respond immediately to any non-compliance. I will consult with the work crew and submit any recommended changes/improvements to this procedure to the Technical Endorsee for consideration in subsequent revisions to the document. Name: Signature: Date: Employee By signing this record, I acknowledge I have been provided a clear explanation on the correct interpretation and proper implementation of this procedure. I also acknowledge I have been given ample opportunity to ask questions relating to this procedure and those questions (if any) have been satisfactorily answered. DO NOT SIGN THIS RECORD IF YOU DO NOT UNDERSTAND, DO NOT AGREE OR DO NOT INTEND TO COMPLY WITH THIS Family Name First Name Job Description (Trade/ Classification) Signature Date Of Induction Attendance Verified By Review Date: Page 12 of 13

13 Family Name First Name Job Description (Trade/ Classification) S.D.F Electrical Pty Ltd Signature Date Of Induction Attendance Verified By Review Date: Page 13 of 13