Excavating Near Northpower Underground Cables and Poles
There are restrictions on excavation or other interference with the land to be undertaken within specified distances of Northpower’s underground electricity and fibre telecommunications reticulation, poles and support stays.
Why is it important to check for underground cables before excavating?
It is important you know where underground power cables are located before undertaking any excavation work for your safety and those of others around you. If power cables are struck it could result in an electric shock, explosion and the loss of power. It is the legal responsibility of the person intending to excavate, that they determine whether or not there are any services in the vicinity before commencing work.
Safe Digging Process
1 Check for cables before excavating
Prior to starting any excavating you will need to check if there are cables in the vicinity.
To check for cables and to book a cable location enter the request on the Before U Dig website www.beforeudig.co.nz
If adequate notice is given of at least two working days, this service is currently free during normal working hours (7.30 a.m. to 4.00 p.m. weekdays).
2 Restrictions for excavating within safety clearances
If the excavation is within the safety clearances for underground cables or greater than the safe excavation depths near poles specified then either of the following is required:
- The excavation is to be conducted by or supervised by a person with a current electrical practicing certificate or,
- A restriction for excavating near underground cables form or a restriction for excavating near poles form must be issued by Northpower.
To obtain a restriction form call Northpower Dispatch on 0800 10 40 40 during working hours at least 2 working days before commencement of work.
Any on site supervision which we may deem necessary to avoid damage to Northpower’s reticulation or equipment, is free during our normal working hours.
3 Hand dig within safety clearances
When excavating near cables, mechanical digging aids must not be used, within the specified safety clearances from a cable, where the location of cables is not certain. Hand digging or potholing to locate the cable must take place before mechanical diggers are used.
Safety Clearances for Excavating near Underground Cables
400 V, 11,000 V & Fibre Distribution
500 mm from located cable position
Critical Cables, All 33,000 V to 110,000 V and Express 11,000 V
2.2 m from located cable position, Northpower supervision required
Cable rising up pole
2.2 m from pole
For critical cables Northpower supervision (standover) is also required for the excavation.
The following is to be noted and requirements also to be met:
- Cable locators are not exact.
- Construction plans and supplied maps do not always show the correct cable location.
- Cable depths may vary due to road works or other earthworks.
- Cables may be buried with timber, concrete or plastic slabs for mechanical protection, be buried inside ducts and/or have orange plastic danger warning tape indicating cables below.
- Cables should not be moved without Northpower approval or supervision.
- The excavation is to be backfilled with suitable material that does not damage the cable.
- Any protection or tape disturbed by the excavation is to be replaced in its original position.
- The land is to be reinstated and cable depth is to remain compliant with Northpower’s standards.
Safety Clearances for Excavating near Poles
Distance from Pole or Stay
Safe Excavation Depth
Within 2.2 metres
Down to 300 mm
Between 2.2 and 5 metres
Down to 750 mm
Note that these requirements apply to poles supporting Northpower electricity or fibre reticulation.
The excavation will require backfilling and reinstatement without compromising pole stability.
Charges will be made for services provided outside working hours, and we reserve the right to charge if less than two working days’ notice is given.
Please note that any person causing any damage to Northpower cables or poles may be liable for the cost of repair.
Northpower has the right under the Electricity Safety Regulations 2010 to prevent any work continuing which is likely to cause or present a significant risk of serious harm or damage.
Note that there may be other electricity, streetlight and telecommunications cables and other services on site that are not owned by Northpower and will not be shown on Northpower plans or have been located by Northpower.
To report any damage call Northpower faults immediately 0800 10 40 40 (24 hour)
For any additional information on Northpower reticulation phone 09 430 1803 (working hours)
Northpower uses the Department of Labour’s Guide for Safety with Underground Services to develop its policy for the location of underground cables. This is available from www.worksafe.govt.nz.
Details of restrictions on excavating near poles are provided in section 2 of NZECP 34 NZ Electrical Code of Practice for Electrical Safe Distances.