7.1      Control Panel

A local control panel shall be provided by the Vendor.  It shall be ingress protected to IP54 minimum and fabricated from heavy gauge sheet steel with fully opening gasketted doors.  Cable entry shall be provided using removable gland plates.

The control panel shall be complete with all internal wiring, relays and terminal blocks to receive the Purchaser’s connections.  All terminal blocks and connectors are to be numbered and all wires to be numbered and identified with core markers.  Vendor shall prepare terminal block diagrams to clearly indicate the interface between Generating Unit termination, Purchaser’s incoming connections and also between each item of the Generating Unit package.

A final “As Delivered” schematic and wiring diagram shall be fixed to the inside of the panel door suitably protected by a transparent cover.

Current Transformers (CT’s) required for the Generating Unit shall be supplied by the Vendor but specified by the Purchaser.  CT’s required for protection and metering shall be specified by the Principal, and supplied and installed by the Vendor.

Voltage signals from voltage transformers (VTs) at the switchgear shall be provided, housed and wired by the Vendor.

Voltage signals from voltage transformers (VTs) at the switchgear shall be provided by others.

The control panel shall provide the following features:

• Start-up control system utilising a 24V DC supply provided by the Generating Unit Vendor.
• Automatic start-up of equipment initiated from loss of supply on busbars of HV Black Start Switchboard or from a signal from the plant fire and gas system or the load management system.
• Tripping of automatic fuel shut off valve from a remote facility provided by others.
• Automatic voltage regulator and field forcing circuit.
• Excitation controls (see 7.3).
• Electronic governor controls (see 7.3).
• Check relay to ensure busbars of Black Start HV Switchboard are isolated from mains supply before generator circuit breaker is automatically closed in auto-start condition.

7.2    Alarms and Shutdowns

A self-contained annunciator panel, with 25% spare windows, shall be provided by the Vendor, incorporating the following alarm and shutdown indicators using a first up alarm annunciator system mounted on the local control panel.  Red or yellow lamps shall flash on a fault and sound an audible alarm.  By pressing the accept button the audible alarm shall be silenced and the lamp energised continuously from the flash mode until the fault is cleared.  The alarm system shall be operated at 24V DC.

Vendor shall include suitably rated transformers and rectifiers within the control panel to produce these voltages from the main supply.

	Alarm	Shutdown
Gen. set not available for auto-start	X
Engine fails to start	X
Low lube oil pressure (pre-alarm)	X	X
High lube oil temperature	X
High jacket water temperature (pre-alarm)	X	X
Engine Overspeed		X
Inlet air filter restricted	X
Exhaust temperature high	X
High generator winding temperature	X
High generator bearing temperature	X
Generator field failure	X	X
Load threshold limit	X
Generating winding fault	X	X
Low hydraulic oil accumulator pressure	X
Radiator CW level low	X

Volt free contacts for remote signalling a common unit fault and also a shutdown are to be provided.  (Refer to Specification for Electrical Equipment)

Generator metering and protection CT’s shall be connected to a suitable junction box equipped with terminals (and shorting links) to enable hook-up by others.

 

7.3    Local Controls and Indications

Each Generating Unit local control panel shall be provided with the following:

Controls

• Emergency stop button
• Manual/auto selector switch for engine start
• Local/remote selector switch for manual start
• Manual start/stop
• Raise/lower speed and local/remote change over switch
• Raise/lower excitation and local/remote change over switch
• Manual/auto selector for synchronisation

Indication

• Engine ready to start
• Engine running
• Tachometer
• Generator volts
• Generator amps
• Power factor
• Circuit breaker open/closed indicating lamps
• Jacket water temperature
• Jacket water heater energised
• Exhaust temperature
• Engine oil pressure
• Engine oil temperature
• Air inlet filter high differential pressure
• Running hours to totaliser

The panel shall be complete with all internal wiring, relays, number terminal blocks and connectors for external cables.  All cables are to be clearly identified in accordance with a system to be agreed with the Purchaser.

Such items as the Manual/Auto selector switch and the fuel supply control or isolating devices, which prevent an automatic start-up and auto connection to busbars, shall be fitted with auxiliary contacts so as to provide the “Generator set not available for auto-start” alarm.

7.4    Remote Controls and Indications

Vendor shall provide terminations at the Local Control Panel for the following indications to interface with a remote panel.  The equipment, housing and wiring will be provided by others.

• Common Trip
• Common Alarm
• Remote Stop

(Refer to Specification for Electrical Equipment)

7.5    Control Panel Wiring and Interconnections

Control wiring shall be carried out with multi-stranded copper conductors with a minimum size of 1.5mm² internal.  External electrical wiring shall have a minimum size of 2.5mm².

All cables and wiring shall be constructed to BS 6883.

Control wiring shall be terminated at easily accessible clamp type terminal blocks, wiring ends shall have a pin type or spade type crimped terminal to suit.

All current transformers secondary wiring shall be carried out with multi-stranded copper conductors with a minimum size of 4sq.mm.

Minimum voltage grading of small wiring shall be 600 volts.

All wiring shall be clearly identified by means of permanent cable identification markers and colour coding for each voltage level.  Colour BLUE is for intrinsically safe circuits only and shall not be used for any other circuits.

Circuits and terminals operating at different voltages and/or performing a different function shall be segregated.

Intrinsically safe circuit terminal bases shall be physically segregated, or have a steel barrier, from other terminal bases.  Intrinsically safe circuit wiring shall be blue, relays and terminal bases shall be labelled ‘IS’.

Terminals associated with external sources of supply shall be fully shrouded and shall carry a label warning personnel to isolate the supply at source before commencing work.

Emergency circuits and shutdown systems shall have cable and wiring which satisfy IEC331.  All other cable and wiring shall have reduced fire propagation qualities to at least IEC332-3.

All insulating material shall be flame retardant, low halogen content.

Control wiring on the generating unit shall be neatly run, properly supported and protected from mechanical damage.

Control wiring shall be to edge of skid terminal boxes.  Separate boxes shall be provided for each voltage/circuit type.

All control wiring between the skid and remote control panel(s) shall be by others.

7.6    Generator Threshold Alarm

A threshold alarm with an adjustable 0-3 minute time delay suitable for a variable loading between 70% and 110% of full load shall be supplied and connected to the annunciator panel.