Section 4.00 4.01 General

SECTION 4.00 4.01

HV SUPPLY/DISTRIBUTION – PERFORMANCE SPECIFICATION

General

This section of the works is a performance specification which the contractor will be responsible for the design deliver, test, install and commission of the 6600/430V supply and distribution system. The Contractor shall employ an approved specialist Sub-Contractor to carry out the complete HV Distribution and installation and if necessary a HV Consulting Engineer for the Design. The works shall include but not limited to the following:o o o o o o o 4.02

HV Distribution Main HV Switchgear HV Cabling Installation Transformer Testing & Commissioning Drawings & Operations Manuals HV Calculations Description of Works

Generally the HV Supply & Distribution will be served via NIE 6.6KV 1.4MW supply terminating in RMU inside the site boundary as indicated on the drawings. It is envisaged that the Contractors design will include the following:1. 2. 3. 4. 5. 6.

Customer owned RMU c/w incoming and outgoing VIP300 electronic O/L & EF Protection Relay’s and GRP enclosure on a concrete base. (located adjacent NIE Ring Master Unit). HV Cabling Network (Radial Supply) including any Pilot/Control cables to the rear of the site to the Proposed Transformer Location. 1650KVA Oil Filled Transformer (DYN II) unit c/w HV circuit breaker and LV circuit breaker. Transformer shall be enclosed in GRP type weather proof enclosure. Suitable earthing mats at RMU and Transformer locations. Test & Commissioning of the complete installation.

1.

Main Switchgear

a)

supply, deliver and install 1 x Schneider RMU, Type RN2c complete with VIP300 electronic O/L an EF protection relay.

b)

supply, deliver and install GRP enclosure to protect switchgear from view and protect against

c)

set relay to provide protection and discrimination for the site load.

d)

Test and leave in safe and proper working order.

2.

Transformer

a)

supply, deliver, erect and connect 1 x 1600kva 6600/433V standard distribution transformer, connected to Vector group DYN II, Oil filled and c/w off load tap change switch to give +/- 2.5% + 5% selection. Cable termination boxes would be arranged for 16 x 1c 300mm2 cables in the secondary side, bottom entry.

b)

supply and deliver a ring main unit as detailed above and directly complied to the primary side of 10

the TRX including suitable bracing and supports. c) d)

supply, deliver and erect suitable GRP enclosure to house all switchgear and transformer. set relay to provide discrimination with the main switchgear and TRX.

e)

test and leave in a safe and proper working order.

3.

HV Cable

a)

Supply, deliver, erect and install 3 core 95mm2 XLPE/SWA/PVC cable c/w copper conductors and insulated for operation on a 6350/11000V system.

b)

cable should be finished in red PVC over sheath and embossed with the voltage category.

c)

supply and install heavy duty maker tape 1mm thick PVC and labeled ‘WARNING PRESENCE OF HV CABLE BENEATH”.

d) end

supply and install suitable termination kits using heat shrinkable components to connect each to the switchgear.

e)

pressure test the completed installation and leave in a safe and proper working order.

4. a)

LV Cable supply, deliver and install single core 300mm2 XLPE/AWA/PVC cable from the secondary terminals of the TRX to the incoming terminals of the Main Circuit Breaker on the LV Switchboard. Install in Trefoil formation having 4No. cables for each phase and 4 cables for the neutral connection. b)

supply and install aluminum glands and locknuts to terminate the cables and connect to the transformer primary winding and the switchgear.

c)

test and leave in a safe and proper working condition.

It will be the Contractors responsibility to check the existing phase rotation for HV & LV systems to determine if they are standard or non-standard. The contractor must determine HV rotation from NIE and establish LV Rotation from site. The contractor shall visit the site and inspect the site conditions, levels etc prior to submitting their tender. No additional claims will be entertained which could have seen forseen during the pre-tender site inspection.

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4.05

Alternative Proposal

The tender shall be based on all new equipment RMU’s, Transformer etc however the Contractor is asked to submit an alternative quotation/tender price for re-conditioned equipment. All re-conditioned equipment shall be fully certificate and a 2 year warranty provided from the date noted on the practical completion certificate. 4.06

Builders Work Drawings

The Contractor is responsible for providing full detailed BWIC drawings, these drawings shall generally include base details, ducting routes and installation methods, cable ways etc as well as co-ordination with all other underground services. 4.07

Shunt Trip

The Contractor shall provide shunt trip wall mounted push buttons in the Main LV Switchroom. 4.08

Regulations

The complete installation shall be in compliance with BS 7671 : 2008 and current amendments. 4.09

Cable Installation

Where HV cabling is laid under roadways, under and into buildings be installed in 150mm O HD PVC (Red) ducting – only 1No. HV cable shall be installed in each duct. Ducts shall be laid on 100mm thick bed of 10mm single sized granulated material and covered with 100mm layer of the same material. This layer shall be covered with 400mm layer of selected fill. One or more continuous plastic marker strip marked ‘DANGER ELECTRICTY’ shall be laid on the selected fill to effectively cover the area of the ducts. The trench shall be back filled and hard compacted in 150mm layers and finally made up to finished roadway level in accordance with the roadway specification to give a minimum cover of 1000mm. All ducts containing a cable shall be sealed at each entry by means of a split wooden bung bored out to the cable diameter, a layer of DENSO Mastic (Plast) 100% spare ducts shall be provided. Where the 1000mm coverage over ducts cannot be achieved the ducts shall be haunched and covered with concrete. Horizontal clearances Between LV Cable & LV Cable – 150mm Between LV Cable & HV Cable – 300mm Between LV Cables & Telephone/Data Cables – 450mm Between HV Cables & Telephone/Data Cables – 500mm 4.10

Earthing

Refer to clause 10.09 MV/HV Earthing. 12