Meter Cabinets and Metering Rooms supplied by underground cables
1. General
1.1 EAC as Distribution System Operator has the exclusive jurisdiction to decide, depending on the nature and capacity of its network, whether the method of electrification of a development will be carried out by:
The timing and the decision of the method of electrification of a development, the obligations of Building Developers and Land Developers as well as the obligations of EAC are covered by the "Policy of the Authority on submitting its views to the Appropriate Town Planning and local Authorities on the issue of Building Permits and Permits for the division of land and electrification methods"
The study for the needs of meters as regards type and number, for the arrangement and sitting of the Metering Room and for the installation of the conduits for the underground cables of EAC for electrification of the application is the responsibility of the applicants (Electrical Designers and Architects). The design must be curried out on the basis of the requirements and specifications of the Authority as they are designed herein and on the basis of typical plans for Meter Cabinets and Metering Rooms which are available and must without exception be approved by EAC.
For facilitating the Designers ( Electrical and Architects) and of Land Developers the Electricity Authority prepared detailed plans with a variety of versions and sittings of meter cabinets and metering rooms depending on the required number of meters, the electric load applied for and the available spaces of the development .
It is stressed that the decision regarding method of electrification of the development (Substation, underground service, overhead service) falls within the exclusive jurisdiction of EAC.
The location (sitting) and the detailed plans of the Meter Cabinets and Meter Rooms as well as the route of the ducting,for the passage of the underground cables and the manholes proposed by Private Designers must be submitted to EAC for approval.
If the approval of EAC is not forthcoming it is possible that the needs of the development in electrical loads may not be feasible, and that expensive structural modifications may be necessary, and delays in electrification may result or even complete inability of electrification, situations for which EAC will not have any responsibility.
2. Important Information
2.1 The subject of electrification method and the subject of design and construction of the Metering Room/Cabinet constitute separate actions which receive separate handling:
2.2. It is an obligation of the applicants who are applying for electrification to construct the cabinets/metering rooms, the requisite manholes, conduits for the passage of underground cables or the conduits of the installation for the passage of the overhead conductors in accordance with the requirements, indications, specifications and approval of the Authority.
2.3. The cabinets/metering rooms must be constructed exactly as indicated on the construction plans and in accordance with the indication of the competent officers of EAC and the relevant notes accompanying the construction plans so that
Feeding cables may be easily installed, but also
Feeding cables and other metering room equipment may be maintained in the future and
Current carrying equipment may be protected and safe at the same time for the occupiers of the building and those who work in it.
2.4 Special attention must be paid to the dimensions and construction details of manholes and of conduits for the passage of the cables of EAC. In or below the metering Rooms and in manholes and conduits for EAC cables there should not be any cables belonging to the customer, water pipes or sewers or any other installation except the installations of EAC.
2.5 It is recommended that cabinets/metering rooms
2.6 The photovoltaic provision on the typical plans for meter cabinets which are available concern a single phase meter. The required space for the customer's installations should be specified in cooperation with the suppliers/installers of the photovoltaics – hence wherever there is provision for a three-phase meter (production>5 kVA) the meter cabinet should be increased accordingly.
2.7 For any technical information regarding metering rooms and meter cabinets, the electrical designers and the electrical installation contractors must communicate with the Installation Inspection Department of EAC.
2.8 Electrical loads of a single consumer which exceed 500A, cannot be supplied at low voltage. Such loads are supplied at medium voltage from dedicated substation or transformer for the consumer. In this case a substation must be agreed with in the applicant's own development with competent officers of the Authority in accordance with the
"Policy of the Authority on submitting its views to the Appropriate Town Planning and local Authorities on the issue of Building Permits and Permits for the Division of land and electrification methods"
3. Categories of Meter Cabinets/ Metering Rooms
The area of EAC meter installation are divided into the following categories depending on the number of meters which may be installed, the magnitude of the load to be metered and the available spaces of the development.
3.1 Meter Cabinets
They satisfy a small number of meters. They are suitable for houses, industrial and commercial buildings and small blocks of flats.
3.1.1 Independent low cabinets-supply via an underground cable
The are used for small electric loads
They are used for small electric loads, smaller than 100A and for up to 2 three-phase meters
They can be constructed as independent structures along or right angles to the development and the road or along the boundary which is adjacent to a green space or a pedestrian road. It is not recommended to be along the boundary of plots belonging to others.
In the set of plans "Independent low Cabinet" construction details are given for:
3.1.2 Build – in Cabinets -supply via underground cable
They are used for small loads, smaller than 100A. For larger loads or for more than two meters other types of cabinets must be used or appropriate modification should be carried out in communication with EAC officers.
These cabinets can be in contact with buildings such as walls, garages, verandas etc. It is not recommended to be in contact with plots belonging to others.
In the set of plans "Build – in Cabinets" details are given for:
3.1.3 Cabinet with opening Meter Board-supply via underground cable
It is used for electric loads smaller than 100A per meter. It has the capacity for up to 16 equivalent single phase meter positions. This means that 14 single phase meters or 7 three-phase meters – including the meter for any communal services and two single-phase meter positions for tariff receivers may be accommodated.
They can satisfy the needs in meters of small blocks of flats, small complexes of warehouses or small industries with common meter positions and small electrical loads.
They can be constructed as independent structures adjacent to building or at the ground level parking area of a block of flats.
In the set of plans "cabinet with opening Meter Board" construction details are given for:
3.1.4 Cabinet with Metering Panel –supply via underground cable
It is used for industrial or commercial developments with usually one consumer having large electric load which requires the installation of a "Metering Panel"
They can be constructed as independent building structures or as a part of the building development.
In the set of plans "Cabinet with Metering Panel "construction details are given for:
3.2 Metering Rooms
Metering Rooms are used for the illustration of a large number of meters and can be accommodated at the ground floor or in the basement of buildings.
3.2.1
Metering Rooms at Ground Floor/ ground level parking area
For choosing a suitable metering room the notes accompanying the typical plans for metering rooms should be diligently studied by architects as well as electricians. In some types of metering rooms no more than 45 single phase meters (22 three-phase) may be installed.
It should be noted that that if a consumer requires a load of over 100A a "metering panel" is required which needs a space of 80cm width and 120cm height.
Some types of metering rooms cannot satisfy total loads in excess of 300KVA. If suitable types of metering rooms are chosen which can satisfy loads in excess of 300KVA, the provisions of the notes on the plans which should always be approved by the competent officers of the Authority must be adhered to.
Special attention should be paid to the dimensions and the position of the terminal manhole as well as to the manner in which conduits for the passage of underground cables terminate within the manhole. Special care should be given when alternative method 1 of the typical plans for the cable entry into the manhole is chosen. In these cases the detail shown in section B-B should be accurately applied.
In the set of plans "Metering Room at the Ground Floor/ ground level parking area » construction details are given for various configurations of the metering room.
3.2.2 Metering Rooms in the Basement –supply via underground cable
For choosing a suitable metering room the notes accompanying the typical plans for metering rooms should be diligently studied by architects as well as electricians. In some types of metering rooms no more than 45 single phase (22 three- phase) meters may be installed.
Care should be taken so that if any consumer requires a load in excess of 100A then a "metering panel" will be required which needs a space of 80cm width and 120cm height.
Some types of metering rooms cannot satisfy total loads in excess of 300KVA. If suitable types of metering rooms are chosen which can satisfy loads in excess of 300KVA, the provisions of the notes on the plans which should always be approved by the competent officers of the Authority must be adhered to.
The fact that the metering room is situated in the basement of the building requires that special attention be given to both the arrangement as well as to both the arrangement aw well as to the manner of entry of the underground service cables.
For easier maintenance of EAC installations and for minimising possible dangers, it is recommended that metering rooms be adjacent to the boundary of the building with the public road.
The method of entry of the conduits for the cables of EAC into the metering room must be in accordance with the typical plans of EAC. For assisting electricians and architects, sections with details of the position of the conduits, of the position of the fuse box and of EAC cables are given on the various typical plans.
In the set of plans
"Metering Room at the Basement" construction details for various arrangements (configurations) of the metering room are given.
4. Calculation of the dimensions of the Meter Board in Metering Rooms
On the meter board:
Single phase meters occupy one position (dimensions 25cm width, 33cm height)
Three phase meters(electrical load<100A) occupy two positions (Dimensions 50 cm width, 33cm height)
Three phase meters (electrical load>100A = Metering panel) occupy a space of dimensions, 80cm width and 120cm height.
Tariff Receivers occupy one position each (dimensions 25cm width X 33cm height each)
Ripple control receiver occupies one position (dimensions 25cm width X 33cm height)
Three phase meters are used in all the following cases without exception:
For electrical loads in excess of 100A a "Metering Panel" is required as mentioned above.
The Meter Boards have fixed height which can accommodate four rows of meters smaller than 100A.
The space needed for Metering panels (electrical load >100A) is added separately and in addition to the above.
Based on the above for calculating the requisite width of the meter board:
Building comprises |
Single phase Meter (<100Α) |
Three phase Meter (<100Α) |
Metering Panel (> 100Α) |
Storage Heaters (<100Α) |
| (1 position) | (2 positions) | | (2 positions) |
3 Shops | 0 | 3Χ2=6 | 0 | 0 |
2 Offices | 0 | 2Χ2=4 | 0 | 0 |
1 Warehouses | 0 | 1Χ2=2 | 0 | 0 |
1 Workshop | | | 1(90cm) | 0 |
2 Flats 3 B/R | 0 | 2Χ2=4 | 0 | 2χ2=4 |
2 Flats 2 B/R | 0 | 2Χ2=4 | 0 | 2χ2=4 |
2 Flats 1 B/R | 2Χ1=2 | 0 | 0 | 2χ2=4 |
1 Communal Services | 0 | 1Χ2=2 | 0 | 0 |
| | | | |
Receiver Positions | 2Χ1=2 | 0 | 0 | 0 |
Ripple Control Receiver (RCR) | 0 | 0 | 0 | 1x1=1 |
TOTAL | 4 | 22 | 90cm | 13 = 39 positions |
| | | | +Metering Panels |
This rounded up figure is multiplied by 0,25m, the width of each column of single-phase positions. The resulting number is the required width of the meter board for meters<100A
To the above figure we add 0,80m for each one of the metering panels required.
Meter Board with calculation
Number of columns = 39/4 = 9,75 =>10 (rounded upwards)
Width of Meter Board = 10 x 0,25(width of column position of single phase meter)=2,50m + 0,80m (one metering panel) = 3,30m
=> Width of Meter Board = 3,30m
When the meters are distributed on two or more meter boards, special attention should be given, as shown on the typical given drawings. For the calculation of meter board width, a spreadsheet is available
5. Comments
Special attention should be paid to the choice of a suitable Metering Room/ Meter Cabinet depending on:
If a particular case studied by the Consultant Designers does not fall within any of the categories of Metering Rooms which are proposed by EAC the necessary modifications to the metering room chosen must always be carried out in communication with the competent officers of EAC.
For informing the interested parties on the method of supply to the development which they are studying or for securing approval of the plans of the Meter Cabinets/ Metering rooms by the competent EAC personnel, a meeting should be arranged with appropriate Planning Departments at the Authority's Area Offices submitting for the purpose the form"Form for the stipulation of EAC views on the method of electrification-arrangement of a meeting"
The meter cabinets/Metering Rooms are always constructed on the basis of the plans and the notes accompanying each plan.
On the typical plans for manholes for acceptance of EAC cables construction details are given for intermediate and angle manholes which should be used in cases where such manholes are required.
The dimensions and details of terminal manholes which should be used in metering rooms are given on typical plans of meter cabinets/metering rooms. Details for the manhole covers are those shown on the terminal service manhole on the "typical plans for manholes for accepting cables".
On the typical EAC plans "typical arrangement for the installation of plastic conduits", details are given on the arrangement, depth and other construction details for the installation of conduits for supplies to buildings.
For the public's safety as well as for the employees' safety, the upper part of the conduits should not be at a depth of less than 60cm from the surface of the soil or the finished floor level at any point along the route.
The service conduits at buildings must pass through empty spaces of communal areas or parking spaces. They must not pass through warehouses, toilets, the electrician's room, engineer rooms, water reservoirs or other private spaces.