Glossary terms beginning with N

Terms used within Transpower
Click one of the letters above to go to the page of all terms beginning with that letter.
near miss

An unplanned event which has potential for: causing serious injury or serious harm to contractors, their employees, or members of the public; and/or causing an electrically initiated fire which results in property damage; and/or causing an environmental incident.


A resistor between the neutral point of a generator or transformer and earth, designed to limit prospective fault currents.


Usually a sub-transmission system primarily for the distribution of electrical energy to end users from the grid, other networks and generating sets directly connected to the network. The term may also be primarily used for the connection of several generating sets distributed over a wide geographical area, to the grid, to other networks and to end users. [GOSP glossary].

network carrier

A provider of telecommunications circuits to a Transpower substation site. Network carrier includes telecommunications companies, and any other organisation including electricity distribution companies implementing communications circuits to a Transpower substation.

network operator

An entity responsible for the operation of a network. [GOSP glossary].

network owner

network owner.

network risk register

A register of system deficiencies, or situations where security cannot be maintained, and requires further investigation to determine if further grid or network investment is required.

network/area operator

The person who carries out power system equipment operating and/or control functions to the requirements of the Security Coordinator and Grid Asset Owner.

neutral earthing resistor

A resistor between the neutral point of a generator or transformer and earth, designed to limit prospective fault currents.

neutral voltage displacement

This is the voltage of the neutral relative to earth. As the positive and negative sequence voltages do not displace the neutral, it is equal to the zero sequence voltage.

newly commissioned equipment notice

A warning notice indicating that an item of Transpower equipment is under operational control as from a given date and time.

NMS alarms

Short title for "Nokia Management Alarm Systems".


A designated point within the grid.

nominal discharge current (In)

Is the peak value of the 8/20 ms impulse current, used to classify a surge arrester.

nominal rating

The design rating of the equipment or transmission circuit. For equipment it is often referred to as the 'nameplate rating'.

nominal system frequency

The frequency of 50 Hertz.

nominal tap

The tap position of a power transformer that corresponds to nominal grid/power system voltages.

non-continuous load

A load which is energised for a portion of the duty cycle greater than one minute. It may be for a set period, removal may be automatic or by operator action or it may continue to the end of the duty cycle.

non-metallic crossover cable

Non-metallic cable used to interconnect two joint boxes on different transmission lines.

non-urgent work

Work that is not required to be done immediately or urgently, and that can be planned as a scheduled outage. See urgent work.

normal system conditions

The state of the power system when it is operating in accordance with statutory requirements as regards quality of supply and within the basic design and operational parameters.

not available to the reactive power control

An item of equipment which cannot be controlled by the RPC scheme. May be due to protection action or by manual selection.

not connected to the system

A circuit that cannot be livened by a normal operating action, such as closure of a disconnector or circuit-breaker. Such a circuit will usually be isolated from the system by the physical removal of connecting spans, or jumpers.

notice of initial transmission line livening

A published notice that warns the general public that a stated transmission line must be treated as alive.

notifiable accident

An accident which is notifiable to authorities under the HSE, Electricity, HSNO or RMA Acts or any regulations thereto.


New Zealand Electricity Market. The wholesale electricity market where the spot price for electricity is determined.


New Zealand Qualifications Authority.