Emisión del voto a distancia; facultades para el desarrollo de

13.1 INTRODUCTION

An emergency power supply system shall be provided for all consumers, which are to be operational under emergency conditions. Essential consumers which are needed during periods where the main power supply is not available (e.g. start-up) shall be connected to this supply.

The emergency power supply system shall consist of diesel power generator, connected to a dedicated part of the low voltage switchboard (hereafter called the essential switchboard), UPS-systems for the supply of safety consumers, and DC-Systems with battery back-up where required by the relevant consumers.

13.2 GENERAL SYSTEM LAYOUT

The emergency power supply systems shall be located in a safe area, separate from the main power generation and protected from external fires in accordance with SOLAS requirements for segregation of spaces.

All cabling of the system that is required to operate under emergency conditions shall be fire resistant.

In general all electrical consumers shall be graded in four categories:-

• U: non-essential

• N: normal

• C: critical

Critical and Safety Consumers shall be supplied with electrical energy under emergency conditions from the generator; if no break supply is required by certain consumers this shall be via UPS-systems. Shut down and load shedding of consumers fed from the essential switchboard under emergency conditions shall be considered.

13.3 CRITICAL AND SAFETY CONSUMERS

The following systems shall be supplied from the emergency diesel generator for duration of at least 24 hours.

• HVAC for the following rooms: Local Technical Room (LTR)

• Emergency lighting

• AC/DC UPS with 4 hours autonomy

• UPS system for Navigational Aids with 96 hours autonomy

• Battery Chargers

• Potable water pump

• Hydraulic power units

• Methanol injection pumps

In case of failure of the diesel generator, the safety system, which is supplied with battery backup, will remain operational for a pre-determined time.

13.4 EMERGENCY DIESEL POWER GENERATOR

The emergency power shall be generated by diesel generator, connected to an essential busbar of the low voltage switchboard.

Each diesel generator shall have a day tank of sufficient capacity to enable it to run at full load for 24 hours.

Each diesel generator shall have two independent starting systems, each with a capacity of at least three consecutive starts.

The emergency generators shall be enclosed and separated by A0 rated fire walls and decks.

After six unsuccessful attempts to start, the automatic start sequence shall be stopped an alarm shall be annunciated. The diesel generator (if any) shall be inhibited in case of gas detection in its air intake.

13.5 ESSENTIAL SWITCHBOARD

The essential switchboard shall be located near the low voltage switchboard and shall be equipped with all control and protection devices for the emergency consumers and the emergency generator.

Synchronising of the emergency generator with the main power supply system shall be possible.

If consumers are supplied from the emergency switchboard, which are not safety consumers but needed under special conditions, when the main power is not available (e.g. start-up) load shedding shall be considered for emergency operations.

13.6 UPS-SYSTEMS

In addition to the emergency generator, transitional sources of power by means of UPS-Systems shall be provided for consumers which need an uninterruptible power supply.

The UPS-systems shall consist as a minimum of: • Rectifier

• battery bank • Inverter

• static bypass switch • manual bypass switch • bypass transformer

The capacity of the battery bank shall be sufficient to supply the connected loads for an autonomy period as mentioned in item 13.3.

The UPS-systems shall be fed from the essential switchboard.

13.7 DC-SYSTEMS

Where consumers require a DC-supply, this shall be provided by dedicated DC-systems with battery back-up for an autonomy period as mentioned in Item 13.3.

The system shall be equipped with two rectifiers, each with sufficient capacity to provide for the full load current to the consumers and additionally the full charging current for the batteries.

The rectifiers shall be fed from the essential switchboard.

13.8 BATTERY ROOMS

Batteries shall be located in dedicated rooms, separate from their chargers. The rooms shall be equipped with separate exhaust ventilation systems.

The battery rooms shall be enclosed in A60 rated fire walls and decks as minimum.

Interlocks shall be provided between the ventilator and the rectifiers in order to inhibit boost charging of the batteries if the ventilation is out of operation.

Electrical installation in battery rooms shall be Ex-protected and certified for use in hydrogen atmosphere, Gas Group B (or IIC as per IP 15) and Temperature Class T1.

13.9 EMERGENCY LIGHTING

Emergency lighting shall be provided for the illumination of technical rooms and other areas of the installation, which are critical for operation. It shall comprise 25% of the installed lighting system as a minimum.

The emergency lighting system shall be supplied from the essential switchboard.

In each area the emergency lighting shall be made so that the area is illuminated via two separate circuits. One of these can be a main lighting circuit. Failure of one circuit shall not render an area completely dark.

The emergency lighting fixtures shall be Ex-protected, in accordance with hazardous area classification.

13.10 SAFETY LIGHTING

The safety lighting system shall illuminate all emergency exits from rooms, escape routes, muster stations, Temporary Refuge and survival craft launching stations, including the water surface below these.

The safety lighting shall be fed from the essential switchboard

Safety lighting shall be provided by use of luminairs with a battery back-up system having an autonomy period of 4 hours after failure of the emergency power supply (See Electrical Design Basis).

The safety lighting fixtures shall be Ex-protected, even if installed in safe areas.

14. NAVIGATIONAL AIDS

14.1 GENERAL

Navigational aids shall be provided for the installation in accordance with the IALA recommendations for the marking of offshore structures, O-114. In addition, aviation obstruction lights and the helideck illumination shall be provided as noted below.

14.2 OPTICAL NAVIGATION AIDS

Generally, at least two primary maritime obstruction lights (beacon lights) shall be installed at prominent position of the complex in such a way, that no dead angle is left on the horizon.

Operation of the light shall be monitored automatically and automatic transfer to a standby circuit shall be initiated in case of light failure.

At each corner of each platform additional red maritime obstruction lights shall be installed.

All maritime obstruction lights and their battery power supply shall be Ex-protected or equivalent such that they can continue to operate after a level 4 ESD (or ESD 0 / Abandon Platform) where a gas hazard situation could exist.

All maritime obstruction lights shall be provided with a battery back-up to give an autonomy period of at least 96 hours.

14.3 ACOUSTIC NAVIGATION AIDS

On each wellhead platform, one or more foghorns shall be provided to ensure the coverage required by the IALA recommendations.

The foghorns shall be provided with a battery-backup to give autonomy of at least 96 hours. The foghorns shall be Ex-protected.

Signs shall be provided near the foghorns to warn personnel of high sound pressure levels in the vicinity.

14.4 AVIATION OBSTRUCTION LIGHTS

Aviation obstruction lights shall be installed on top of all structures higher than the helideck and intermediate at 10 meter intervals, particularly on crane booms and radio masts (is any). The characteristics shall be omni directional and of color red and their intensity shall not be less than 10 candelas.

The highest point of the installation shall be equipped with an omni directional red light of 25 to 200 candela intensity.

The aviation obstruction lights shall be part of the safety lighting system.

14.5 HELIDECK PERIMETER LIGHTING

The helicopter landing area perimeter lighting shall be provided on the Helideck in accordance with the requirements of API RP 2L and CAP 437.

The perimeter lighting shall be part of the safety lighting system.

14.6 HELIDECK ILLUMINATION

The Helideck shall be illuminated by floodlight, equipped with suitable filters and shades in order not to dazzle the pilot and to avoid reflections from the sea surface. Perimeter lights shall be provided in accordance with API RP 2L and CAP 437 requirements. Power supply shall be from the emergency lighting system. The Helideck wind socks shall be illuminated with power supply from the safety lighting system.

14.7 HELICOPTER HAZARD WARNING LIGHT

To warn helicopter pilots landing at the normally unattended wellhead platform, of platform F&G hazards, a system of visual warning lights will be provided. Under normal conditions a flashing GREEN light will show. In the event of confirmed fire or hydrocarbon/toxic gas detection, a RED flashing light will show. (Two status indicators are provided to cover for lamp failure.)

It is to be noted that fire/gas detection on wellheads is alarmed in the LTR allowing the helicopter pilot to be advised by radio of an unsafe situation at each wellhead.