5.16Risk assessment#
| Area of risk | Description of risk | Mitigation of risk | Risk assessment | Comments | ||
|---|---|---|---|---|---|---|
| L | C | R | ||||
| Road lighting, (including tunnel road lighting and busway road median lighting) | Electric shock due to person coming in contact with metal pole during a fault (for example, road crash) | Rate 3 road lighting is energised only at night time. Standard design requires compliance with AS/NZS 3000 including 400 ms disconnect time for final sub-circuit to pole. Maintenance practices require periodic verification of road lighting installations. | U | Mi | L | AS/NZS 3000 specifies a 5 s disconnect time for final sub-circuits supplying fixed equipment. The required 400 ms disconnect time reduces the risk of electric shock. |
| Death or serious injury due to road incident as a result of road lighting being inoperative because of nuisance tripping of RCD | No mitigation – install RCD | A | C | A | In one 18-month period there were three fatalities on Queensland roads where failure of the road lighting was an alleged contributing cause. Road lighting is a recognised aid to reducing traffic accidents. HID luminaires will have leakage current dependent on age and accumulation of environmental factors. Underground cables have normal leakage current due to capacitive effects. Risk of nuisance tripping of RCDs is high with consequent failure of the installation to meet its intended purpose. | |
| Conclusion | Road lighting installations meet the requirements of AS/NZS 3000 Clause 2.6.3.2.1 Exception 5. Transport and Main Roads road lighting installations are required to comply with AS/NZS 3000. The specific deemed to comply requirement for additional RCD protection on lighting circuits in Clause 2.6.3.2.1(b) is not applied as the risk due to the disconnection of a circuit by an RCD through nuisance tripping could cause a danger / risk greater than earth leakage current. The fundamental safety principles of AS/NZS 3000 Part 1 however, are satisfied. |
Table in words
- For the area of risk Road lighting, (including tunnel road lighting and busway road median lighting), the description of risk is Electric shock due to person coming in contact with metal pole during a fault (for example, road crash), the mitigation of risk is Rate 3 road lighting is energised only at night time. Standard design requires compliance with AS/NZS 3000 including 400 ms disconnect time for final sub-circuit to pole. Maintenance practices require periodic verification of road lighting installations., the risk assessment is L U, C Mi, R L, and the comments are AS/NZS 3000 specifies a 5 s disconnect time for final sub-circuits supplying fixed equipment. The required 400 ms disconnect time reduces the risk of electric shock.
- For the area of risk Road lighting, (including tunnel road lighting and busway road median lighting), the description of risk is Death or serious injury due to road incident as a result of road lighting being inoperative because of nuisance tripping of RCD, the mitigation of risk is No mitigation – install RCD, the risk assessment is L A, C C, R A, and the comments are In one 18-month period there were three fatalities on Queensland roads where failure of the road lighting was an alleged contributing cause. Road lighting is a recognised aid to reducing traffic accidents. HID luminaires will have leakage current dependent on age and accumulation of environmental factors. Underground cables have normal leakage current due to capacitive effects. Risk of nuisance tripping of RCDs is high with consequent failure of the installation to meet its intended purpose.
- For the area of risk Conclusion, the description of risk is Road lighting installations meet the requirements of AS/NZS 3000 Clause 2.6.3.2.1 Exception 5. Transport and Main Roads road lighting installations are required to comply with AS/NZS 3000. The specific deemed to comply requirement for additional RCD protection on lighting circuits in Clause 2.6.3.2.1(b) is not applied as the risk due to the disconnection of a circuit by an RCD through nuisance tripping could cause a danger / risk greater than earth leakage current. The fundamental safety principles of AS/NZS 3000 Part 1 however, are satisfied.
| Area of risk | Description of risk | Mitigation of risk | Risk assessment | Comments | ||
|---|---|---|---|---|---|---|
| L | C | R | ||||
| Traffic signals | Electric shock due to person coming in contact with metal traffic signal post during a fault (for example, road crash) | Standard design requires compliance with AS/NZS 3000 including 400 ms disconnect time for final sub-circuit to pole. Maintenance practices require periodic verification of traffic signal installations. | U | Mi | L | AS/NZS 3000 specifies a 5 s disconnect time for final sub-circuits supplying fixed equipment. The required 400 ms disconnect time reduces the risk of electric shock. |
| Death or serious injury due to road incident as a result of traffic signals being inoperative because of nuisance tripping of RCD | No mitigation – install RCD | L | Ma | A | Traffic signal lanterns are part of a traffic safety system. They will have leakage current dependent on age and accumulation of environmental factors. Underground cables have normal leakage current due to capacitive effects. Risk of nuisance tripping of RCDs is high with consequent failure of the installation to meet its intended purpose of safely managing traffic. | |
| Conclusion | Traffic signals installations meet the requirements of AS/NZS 3000 Clause 2.6.3.2.1 Exception 5. Transport and Main Roads traffic signals installations are required to comply with AS/NZS 3000. The specific deemed to comply requirement for additional RCD protection on lantern circuits and supporting communications devices in Clause 2.6.3.2.1(b) is not applied as the risk due to the disconnection of a circuit by an RCD through nuisance tripping could cause a danger / risk greater than earth leakage current. The fundamental safety principles of AS/NZS 3000 Part 1, however, are satisfied. NOTE: Any socket outlets installed in the controller cabinet, and not connected to a critical supporting communications device, must have RCD protection. | |||||
| L | C | R | ||||
| Pedestrian pathway lighting to AS/NZS 1158 (including exterior pathway lighting around bus stations, along bicycle ways, through park areas, carparks, pedestrian underpass lighting, and so on) | Electric shock due to person coming in contact with metal pole during a fault | Rate 3 pedestrian pathway lighting is energised only at night time. Standard design requires compliance with AS/NZS 3000 including 400 ms disconnect time for final sub-circuit to pole. Maintenance practices require periodic verification of road lighting installations. | U | Mi | L | AS/NZS 3000 specifies a 5 s disconnect time for final sub-circuits supplying fixed equipment. The required 400 ms disconnect time reduces the risk of electric shock. |
| Assault, serious injury or death due to criminal activity as a result of pedestrian pathway lighting being inoperative because of nuisance tripping of RCD | No mitigation – install RCD | P | Ma | A | Pathway lighting is a recognised deterrent to criminal activity at night and is designed to help provide a safer environment for users particularly of the public transport system. HID luminaires will have leakage current dependent on age and accumulation of environmental factors. Underground cables have normal leakage current due to capacitive effects. Risk of nuisance tripping of RCDs is high with consequent failure of the installation to meet its intended purpose of providing a safe environment for users at night. | |
| Conclusion | Pedestrian pathway lighting installations meet the requirements of AS/NZS 3000 2Clause 6.3.2.1 Exception 5. Transport and Main Roads pathway lighting installations are required to comply with AS/NZS 3000. The specific deemed to comply requirement for additional RCD protection on lighting circuits in Clause 2.6.3.2.1(b) is not applied as the risk due to the disconnection of a circuit by an RCD through nuisance tripping could cause a danger / risk greater than earth leakage current. The fundamental safety principles of AS/NZS 3000 Part 1 however, are satisfied. |
Table in words
- For the area of risk Traffic signals, the description of risk is Electric shock due to person coming in contact with metal traffic signal post during a fault (for example, road crash), the mitigation of risk is Standard design requires compliance with AS/NZS 3000 including 400 ms disconnect time for final sub-circuit to pole. Maintenance practices require periodic verification of traffic signal installations., the risk assessment is L U, C Mi, R L, and the comments are AS/NZS 3000 specifies a 5 s disconnect time for final sub-circuits supplying fixed equipment. The required 400 ms disconnect time reduces the risk of electric shock.
- For the area of risk Traffic signals, the description of risk is Death or serious injury due to road incident as a result of traffic signals being inoperative because of nuisance tripping of RCD, the mitigation of risk is No mitigation – install RCD, the risk assessment is L L, C Ma, R A, and the comments are Traffic signal lanterns are part of a traffic safety system. They will have leakage current dependent on age and accumulation of environmental factors. Underground cables have normal leakage current due to capacitive effects. Risk of nuisance tripping of RCDs is high with consequent failure of the installation to meet its intended purpose of safely managing traffic.
- For the area of risk Conclusion, the description of risk is Traffic signals installations meet the requirements of AS/NZS 3000 Clause 2.6.3.2.1 Exception 5. Transport and Main Roads traffic signals installations are required to comply with AS/NZS 3000. The specific deemed to comply requirement for additional RCD protection on lantern circuits and supporting communications devices in Clause 2.6.3.2.1(b) is not applied as the risk due to the disconnection of a circuit by an RCD through nuisance tripping could cause a danger / risk greater than earth leakage current. The fundamental safety principles of AS/NZS 3000 Part 1, however, are satisfied. NOTE: Any socket outlets installed in the controller cabinet, and not connected to a critical supporting communications device, must have RCD protection.
- For the area of risk Pedestrian pathway lighting to AS/NZS 1158 (including exterior pathway lighting around bus stations, along bicycle ways, through park areas, carparks, pedestrian underpass lighting, and so on), the description of risk is electric shock due to person coming in contact with metal pole during a fault, the mitigation of risk is rate 3 pedestrian pathway lighting is energised only at night time. Standard design requires compliance with AS/NZS 3000 including 400 ms disconnect time for final sub-circuit to pole. Maintenance practices require periodic verification of road lighting installations., the risk assessment is L C R U Mi L, and the comments are AS/NZS 3000 specifies a 5 s disconnect time for final sub-circuits supplying fixed equipment. The required 400 ms disconnect time reduces the risk of electric shock.
- For the area of risk Pedestrian pathway lighting to AS/NZS 1158 (including exterior pathway lighting around bus stations, along bicycle ways, through park areas, carparks, pedestrian underpass lighting, and so on), the description of risk is assault, serious injury or death due to criminal activity as a result of pedestrian pathway lighting being inoperative because of nuisance tripping of RCD, the mitigation of risk is no mitigation – install RCD, the risk assessment is L C R P Ma A, and the comments are pathway lighting is a recognised deterrent to criminal activity at night and is designed to help provide a safer environment for users particularly of the public transport system. HID luminaires will have leakage current dependent on age and accumulation of environmental factors. Underground cables have normal leakage current due to capacitive effects. Risk of nuisance tripping of RCDs is high with consequent failure of the installation to meet its intended purpose of providing a safe environment for users at night.
- For the area of risk Conclusion, the description of risk is pedestrian pathway lighting installations meet the requirements of AS/NZS 3000 2Clause 6.3.2.1 Exception 5. Transport and Main Roads pathway lighting installations are required to comply with AS/NZS 3000. The specific deemed to comply requirement for additional RCD protection on lighting circuits in Clause 2.6.3.2.1(b) is not applied as the risk due to the disconnection of a circuit by an RCD through nuisance tripping could cause a danger / risk greater than earth leakage current. The fundamental safety principles of AS/NZS 3000 Part 1 however, are satisfied.
| Area of risk | Description of risk | Mitigation of risk | Risk assessment | Comments | ||
|---|---|---|---|---|---|---|
| L | C | R | ||||
| Safety Related Traffic Management Devices (including electronic speed limit signs (ESLS), variable message signs (VMS) and enhanced variable message signs (EVMS), lane use management systems (LUMS), road condition information signs (RCIS), overheight vehicle detection systems, conspicuity devices such as flashing wigwags, ramp metering, CCTV) | Electric shock due to person coming in contact with metal parts of equipment during a fault | Standard design requires compliance with AS/NZS 3000 including 400 ms disconnect time for final sub-circuit to pole. Maintenance practices require periodic verification of safety related traffic management installations. | U | Mi | L | AS/NZS 3000 specifies a 5 s disconnect time for final sub-circuits supplying fixed equipment. The required 400 ms disconnect time reduces the risk of electric shock. |
| Death or serious injury due to road incident as a result of safety related traffic management devices being inoperative because of nuisance tripping of RCD | No mitigation – install RCD | L | Ma | A | Safety related traffic management devices are designed to help improve the safety of vehicle and pedestrian users of the road system. They are expected to have leakage current dependent on age, and accumulation of environmental factors. Underground cables have normal leakage current due to capacitive effects. Risk of nuisance tripping of RCDs is high with consequent failure of the installation to meet its intended purpose of safely managing traffic. | |
| Conclusion | Safety related traffic management devices meet the requirements of AS/NZS 3000 2Clause 6.3.2.1 Exception 5. Safety related traffic management devices are required to comply with AS/NZS 3000. The specific deemed to comply requirement for additional RCD protection on these circuits in Clause 2.6.3.2.1(b) is not applied as the risk due to the disconnection of a circuit by an RCD through nuisance tripping could cause a danger / risk greater than earth leakage current. The fundamental safety principles of AS/NZS 3000 Part 1 however, are satisfied. |
Table in words
- For the area of risk Safety Related Traffic Management Devices (including electronic speed limit signs (ESLS), variable message signs (VMS) and enhanced variable message signs (EVMS), lane use management systems (LUMS), road condition information signs (RCIS), overheight vehicle detection systems, conspicuity devices such as flashing wigwags, ramp metering, CCTV), the description of risk is electric shock due to person coming in contact with metal parts of equipment during a fault, the mitigation of risk is standard design requires compliance with AS/NZS 3000 including 400 ms disconnect time for final sub-circuit to pole. Maintenance practices require periodic verification of safety related traffic management installations., the risk assessment is L C R U Mi L, and the comments are AS/NZS 3000 specifies a 5 s disconnect time for final sub-circuits supplying fixed equipment. The required 400 ms disconnect time reduces the risk of electric shock.
- For the area of risk Safety Related Traffic Management Devices (including electronic speed limit signs (ESLS), variable message signs (VMS) and enhanced variable message signs (EVMS), lane use management systems (LUMS), road condition information signs (RCIS), overheight vehicle detection systems, conspicuity devices such as flashing wigwags, ramp metering, CCTV), the description of risk is death or serious injury due to road incident as a result of safety related traffic management devices being inoperative because of nuisance tripping of RCD, the mitigation of risk is no mitigation – install RCD, the risk assessment is L C R L Ma A, and the comments are safety related traffic management devices are designed to help improve the safety of vehicle and pedestrian users of the road system. They are expected to have leakage current dependent on age, and accumulation of environmental factors. Underground cables have normal leakage current due to capacitive effects. Risk of nuisance tripping of RCDs is high with consequent failure of the installation to meet its intended purpose of safely managing traffic.
- For the area of risk Conclusion, the description of risk is safety related traffic management devices meet the requirements of AS/NZS 3000 2Clause 6.3.2.1 Exception 5. Safety related traffic management devices are required to comply with AS/NZS 3000. The specific deemed to comply requirement for additional RCD protection on these circuits in Clause 2.6.3.2.1(b) is not applied as the risk due to the disconnection of a circuit by an RCD through nuisance tripping could cause a danger / risk greater than earth leakage current. The fundamental safety principles of AS/NZS 3000 Part 1 however, are satisfied.