Appendix A: Asset Types, Groups and Subgroups for Electricity Line Businesses
Asset registers should include, as a minimum, the classification of assets such as set out in this appendix.
A. Transpower
(a) AC Transmission Lines
Transmission lines should be divided into subgroups by voltage: 11kV, 33kV, 50kV, 66kV, 110kV and 220kV.
Further subdivision should be by conductor size.
For standard valuation purposes the unit is 1km.
(b) Benmore-Haywards HVDC Link
The Benmore-Haywards HVDC link including land and buildings should be recorded.
(c) AC Substation Equipment
Substations should be divided into subgroups as follows:
| Category | Average No. of Incoming HV bays |
| Major | 14 |
| Medium | 8 |
| Small | 6 |
| Rural | 2 |
B. Transpower and Local ELBs
(d) Subtransmission
Subtransmission Lines
Subtransmission lines should be divided into subgroups by voltage: 22kV, 33kV, 66kV and 110kV.
Further subdivision should be by conductor size (e.g. 185mm2 aluminium, 100mm2 aluminium).
For standard valuation purposes the unit is 1km.
Subtransmission Cables
Subtransmission cables should be divided into subgroups by voltage: 33kV and 110kV. If cable sizes differ markedly within an ELB, the quantities should be recorded separately for ranges of capacity.
For standard valuation purposes the unit is 1 km.
(e) Zone Substations
Zone substations should be divided into subgroups by capacity: 0-5MVA, 6-10MVA, 11-20 MVA, 21-30MVA, over 30MVA.
Numbers of substations should be determined separately for the asset categories identified in Table B.1 of Appendix B.
Equipment owned at associated points of supply should be listed under this section e.g. circuit breakers, metering and communications equipment.
Ripple injection equipment should be included under this class of asset and will incorporate control equipment, tuned circuit, coupling equipment and remote units. The master station should be included separately with the system control facilities.
For standard valuation purposes the unit is one substation.
(f) Distribution
Medium Voltage Lines
MV distribution lines should be divided into subgroups by voltage, conductor size ranges and type:
- 6.6kV, 11kV and 22kV
- (150mm2 to 300mm2 Al incl.) etc aluminium or equivalent
- 3 phase, single phase, SWER
- lines with more than one voltage.
For standard valuation purposes the unit is 1 km.
Medium Voltage Cables
MV distribution cables should be divided into subtypes by voltage: 6.6kV, 11kV and 22kV.
If necessary, they should also be divided by conductor size.
For standard valuation purposes the unit is 1km.
(g) Medium Voltage Switchgear
MV switchgear should be divided into subgroups by type. Voltage regulators are to be included in this group.
(h) Distribution Substations
Distribution substations should be divided into subgroups: pole mounted, ground mounted (covered), indoor (kiosk) or on customers' premises.
Consumer substations with the substation sited in a customer's premises should be treated as a subgroup.
For standard valuation purposes the unit is one substation.
(i) Distribution Transformers
Distribution transformers should be divided into subgroups by size.
For standard valuation purposes the unit is one transformer.
(j) Reticulation
Low Voltage Lines
It should not be necessary to divide low voltage lines into subgroups by conductor size or according to whether there are one, two or three phases. However, the lines should be divided into subgroups by type: overhead and underbuilt. Streetlighting mains, should be recorded separately.
For standard valuation purposes the unit is 1km.
Low Voltage Cables
It should not be necessary to divide low voltage cables into subgroups by conductor size, Streetlighting mains, should be recorded separately.
For standard valuation purposes the unit is 1km.
(k) Customer Service Connections Excluding Meters and Relays
This class of asset includes cable or line connections from the mains to the property boundaries and includes LV fuses. The assets should be divided into subgroups according to whether they are for one or three phases.
For standard valuation purposes the unit is 1 service.
(l) System Control Facilities
Most local ELBs have only one system control centre which, along with any other system control facilities, should be recorded separately as a master station. Remote units should be recorded with the appropriate zone substation.
(m) Communication Facilities
This class of asset comprises:
- terminal facilities: these should be recorded as a group with the master station and the remote units recorded with the zone substation.
For standard valuation purposes the unit is one terminal. - lines/cables: these should be subgrouped if necessary.
For standard valuation purposes the unit is 1km.
(n) Miscellaneous Equipment
This class of asset includes items such as air break switches and auto reclosers.
(o) Stores and Spares
The stock of stores and spares should be recorded.
(p) Land
Land owned by ELBs on which substations are built should be recorded.
(q) Easements
Easements which qualify for assessment (see B.29) should be recorded.
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