Appendix ATest procedure – traffic signals (energised)#

This procedure details the required tests to be conducted for traffic signals when main circuit is live.

Procedure (in order of sequence)#

a)Visual inspection#

1. i.Check for any dangerous vermin/biohazards in the switchboard.
2. ii.Make sure the switchboard door and cabinet are correctly earthed.
3. iii.Make sure the MEN link is available (if applicable).
4. iv.Check that all exposed conductors cannot be inadvertently accessed (IP2X).
5. v.Look for mechanically-damaged equipment, unsupported parts, and cables in tension.
6. vi.Visually check all earthing conductors are connected to the earth bar.
7. vii.Visually check that neutral conductors are connected to the neutral bar.

b)Earth continuity [no voltage test, but working in vicinity of live parts]#

1. i.Isolate supply and confirm no voltage present on load side of main switch and neutral.
2. ii.Complete the following noting any possible risk. Disconnect the main earth and MEN from the neutral link. Disconnection point is the earth bar.
3. iii.Place Ohmmeter between the Earth bar of the controller and the post of each pedestal using suitable trailing lead.
4. iv.Record results (measure the resistance of the trailing lead also). Deduct value of trailing lead from the results to obtain test result.
5. v.Reconnect the main earth and the MEN.

This test can be replaced by completing Earth Fault Loop Impedance test if traffic conditions do not permit use of a trailing lead.

c)Neutral integrity [main circuit de-energised, but working in vicinity of live parts]#

1. i.Turn off main switch.
2. ii.Confirm integrity of main earthing connection as per test sequence b) Earth continuity.
3. iii.Remove main earth and main neutral from main switchboard.
4. iv.Check operation of voltage indicator.
5. v.Test supply side of the main switch and main earth. Result should indicate approximately 230 – 240 Vac.
6. vi.Complete the following noting possible risk. Disconnect MEN link. Test between supply side of the main switch and neutral bar. A result of approximately 230 – 240 Vac indicates other neutral to earth connections within the installation. Remove neutral connection of any such circuit.
7. vii.Isolate CCTS other than the test circuit. Reconnect main neutral to the neutral bar and close the main switch. Apply a substantial load. Test between main switch and neutral bar. Record the reading.
8. viii.Turn off main switch. Remove main neutral and connect main earth. Reconnect MEN link.
9. ix.Turn on main switch and test between main switch and neutral bar. Reading should be substantially the same as for step vii in this test sequence c) Neutral integrity i.e. within 5 volts.

d)Insulation resistance test (via leakage current testing)#

Insulation resistance testing requires the supply to be disconnected; therefore, as per AS/NZS 3019 Clause 4.7.4, leakage current test is to be conducted using a leakage current clamp meter.

1. i.Simultaneously measure the current in the active and the neutral conductors under test.
2. ii.If leakage current is greater than 10 mA per cable run from the controller then the test should be considered to have failed and further testing is required to determine source.

e)Earth electrode, main earth, supply polarity (combined)#

1. i.For earth electrode, perform visual inspection to look for evidence of corrosion, damage or poor connection.
2. ii.For main earthing conductor, perform visual inspection and confirm that:
3. Main earthing conductor is correct size.
4. Main earthing conductor is connected to the earth electrode by a suitable corrosion resistant connection.
5. Main earthing conductor terminations are accessible.
6. Connections are mechanically sounds and fixed to a secure system.
7. Connections are protected against mechanical damage, corrosion or vibration.
8. Connections do not impose any appreciable mechanical stress on components.
9. Main earthing conductor is correctly connected at the switchboard (where applicable).
10. Labelling of the main earth connection is correct.
11. iii.Identify the incoming mains cables, and visually check the active conductor is connected to the current limiting device (main fuse) and the neutral conductor is connected to the neutral bar.
12. iv.Disconnect the main earthing conductor at once established alternative earth exists, using
13. Earth Continuity test (refer to test sequence b) Earth continuity)
14. v.Place Ohmmeter between (end of main earthing conductor) and (body of earthing electrode). The resistance of the main earth conductor shall be less than 0.5 Ω according to Wiring Rules Clause 8.3.5.2.

1. vi.Test voltage between 1 and 3.
2. vii.Test voltage between 1 and 4.
3. viii.Test voltage between 3 and 4.
4. ix.If test voltage for steps vi. and viii. in this test sequence e) are as follows, then polarity is reversed and this needs to be corrected immediately:
5. x.Reconnect main earthing conductor to earth bar.

• Step vii. = 230 – 240 Vac
• Step viii. = 0 Vac

f)Correct circuit connections#

1. i.Prove that the active, neutral and protective earthing conductors of each circuit are correctly connected so that there is no:

• short circuit between conductors
• transposition of conductors that could result in the earthing system and any exposed conductive parts of the electrical installation becoming live
• interconnection of conductors between different CCTS.

g)Earth Fault Loop Impedance#

1. i.Connect Loop Tester at the last pedestal on each run.
2. ii.Measure EFLI, two measurements taken approximately 30 seconds apart.
3. iii.Confirm results are same (within 5%) – otherwise test again.
4. iv.Record the type and size of the Field Active protective device and Flasher Circuit protective device.
5. v.Record all test results (both):

The use of an active core with no other loads (or relatively low loads) will provide more accurate results. Readings can be affected by external factors on the supply side. Further testing may be required if readings are high and do not meet the requirements of Wiring Rules.

h)Earth leakage — each run#

1. i.Connect clamp meter around used actives and neutral only.
2. ii.Measure current differential for each run.
3. iii.Where leakage is noted to be greater than 10 mA, trace leakage back to faulty equipment and rectify.
4. iv.Record all results.

i)Controller voltage and peak current#

1. i.Connect clamp meter around incoming supply active 3 and record peak current result during one cycle of the traffic signals.
2. ii.Test voltage between 3 and 4 record results.

j)Test RCD#

1. i.Perform a visual inspection to make sure the socket outlets are not connected to any circuit used to drive traffic signals.
2. ii.Turn the RCD tester to RCD testing position.
3. iii.Select 30 mA current rating, full sine wave, and 0° current phase.
4. iv.Press and release ‘test’ (or ‘GO’) button, wait for the test to complete. Record the reading to the test report.
5. v.Record trip time and trip current, as well as any other factors of concern.
6. vi.Select 180° current phase, repeat step iv of this test sequence j) Test RCD.
7. vii.RCD that does not operate on test, or takes longer than 300 ms to interrupt the supply, should be replaced immediately.

k)Infrared thermal imaging#

1. i.In accordance with AS/NZS 3019 Clause 5.8, equipment is to operate under normal operating loads for at least 30 minutes.
2. ii.Measure the temperature of the equipment components using the infrared thermal imaging equipment.
3. iii.Determine if any equipment is affected by excessive rise in temperature. If high temperature values are measured, rectify installation. Retest equipment components including use of infrared thermal imaging equipment.

l)Touch voltage testing#

1. i.Confirm no potential exists between the department’s assets and also between assets of other entities and departmental assets.

Drawings from the original pages

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