Chapter 4 Requirements for High Voltage Shore Connection Systems
4.2 Requirements for Equipment
(e) Safety device activation alarm (for example, overcurrent, earth fault)
4.2 Requirements for Equipment
4.2.1 General
Electric equipment shall be made of durable, flame-retardant, and moisture-proof materials; these equipment shall withstand marine environments, such as temperature. The degree of protection of equipment shall be according to 1.11 and 14.2.2 in Part VII of the Rules for Steel Ships.
4.2.2 Preventing condensation
Means to prevent condensation shall be provided if there is a risk of damage of insulation due to condensation of moisture.
4.2.3 Air gap clearance
The air gap clearance of conducting parts in high voltage electric equipment shall be according to 14.2.3 (a) in Part VII of the Rules for Steel Ships.
4.2.4 Creepage distance
The creepage distance of high voltage electric equipment shall be adequate for the rated voltage. Tracking index in the condensation condition of insulation materials according to IEC 60112, or transient over voltage during an accident when circuit breaker is activated, shall also be considered.
4.2.5 Shore connection switchboard
(a) Construction
The shore connection switchboard shall conform to the provisions of IEC 62271-200.
(b) Circuit breaker
(i) Circuit breaker shall be installed in the shore connection switchboard to protect the high voltage cable to the on-board receiving switchboard.
(ii) Low voltage protector (LVP) shall be provided in the high voltage shore circuit breaker.
(iii) The rated short circuit making current of the high voltage shore circuit breaker shall be greater than the maximum prospective short circuit current (maximum peak value).
(iv) The rated breaking capacity of the high voltage shore circuit breaker shall be greater than the maximum prospective short circuit current (rms value).
(c) Instrumentation and protection devices
The instrumentation listed below shall be provided in the shore connection switchboar d. Backup power supply for operation of at least 30 minutes shall be provided for the protection devices. In the event of a breakdown of this backup power supply, alarm shall be given in the machinery control room.
(i) Voltmeter (that can measure voltage in each phase) (ii) Short circuit protection device (open circuit and alarm) (iii) Overload protection device (open circuit and alarm) (iv) Earth fault detector
(v) Unbalance protection device (for multiple connections)
4.2.6 On-board receiving switchboard
Chapter 4 Requirements for High Voltage Shore Connection Systems 4.2 Requirements for Equipment
CR Classification Society GUIDELINES FOR HIGH VOLTAGE SHORE CONNECTION SYSTEMS GD-HVSC-202004 - 14 -
(a) Construction
On-board receiving switchboard shall conform to IEC 62271-200, except when low voltage is received (less than 1 kV) through a transformer.
(b) Instrumentation and protection devices
(i) For load transfer via short term parallel connection, the following instrumentation and protection devices shall be provided in the on-board receiving switchboard:
(1) 2 sets of voltmeters (for on-board power and shore power) (2) Phase sequence indicator for shore power
(3) 2 sets of frequency meters (for on-board power and shore power) (4) Ammeter for shore power (for all three phases)
(5) Synchronizing device
(6) Short circuit protection device (open circuit and alarm) (7) Overcurrent protection device (open circuit and alarm) (8) Overcurrent alarm
(9) Earth fault detection (alarm and insulation system connection, and open circuit if required) (10) Over-voltage/ low voltage protection device (open circuit and alarm)
(11) Over-voltage/ low voltage alarm
(12) High/ low frequency protection device (open circuit and alarm) (13) High/ low frequency alarm
(14) Reverse power protection device (open circuit and alarm) (15) Phase sequence protection device (alarm and interlock)
(ii) For load transfer via blackout, the following instrumentation and protection devices shall be provided in the on-board receiving switchboard:
(1) Voltmeter (2) Frequency meter
(3) Ammeter (for all three phases)
(4) Short circuit protection device (open circuit and alarm) (5) Over current protection device (open circuit and alarm) (6) Overcurrent alarm
(7) Over-voltage/ low voltage protection device (open circuit and alarm) (8) Over-voltage/ low voltage alarm
(9) High/ low frequency protection device (open circuit and alarm) (10) High/ low frequency alarm
(11) Phase sequence protection device (alarm and interlock)
(c) Circuit breaker
(i) The rated short circuit making current of the circuit breaker shall be greater than the maximum prospective short circuit current (maximum peak value).
(ii) The rated breaking capacity of the circuit breaker shall be greater than the maximum prospective short circuit current (rms value).
(iii) Interlocking means shall be provided for the circuit so that the circuit breaker cannot be closed in the following conditions:
(1) One of the earthing switches is closed (shore side, ship side or both) (2) The pilot connection circuit is not established
(3) The emergency shutoff facilities are activated
Chapter 4 Requirements for High Voltage Shore Connection Systems 4.2 Requirements for Equipment
(4) Abnormality such as effect of controller (shore side/ship side) or self-monitoring function (alarm/safety device) on safe connection is detected
(5) Ship-shore communication system (if it exists) is not working (6) High voltage power is not being supplied
(7) Equipotential bonding is not established
(8) Earth fault condition is detected in on-board distribution system
4.2.7 Cable management system
The cable management system shall prevent the tension limits of the cable from being exceeded during cable extension or retraction.
4.2.8 High voltage plug and socket
(a) High voltage plug (limited to ship-shore connections) and high voltage shore circuit breaker shall be provided with interlocking means so that high voltage plug can be pulled out only after the circuit breaker is open.
This interlocking means may be realized through appropriate construction of high voltage plug and socket.
(b) High voltage plug and socket shall be protected from dust, humidity and condensation when not in use.
Degree of protection provided by enclosures for high voltage plug and socket shall comply at least with IP66 rating.
(c) High voltage plug and socket shall be provided with interlocking means so that plug can be pulled out or inserted only when the earthing switch is closed. However, high voltage plug and socket other than for ship -shore connections need not be provided with interlocking means provided that safety measures are adopted during removal (such as automatic opening of circuit breaker, device for discharging residual charge, earthing device).
(d) High voltage plug and socket shall be protected so that internal fault shall not cause harm to personnel.
(e) When inserting the high voltage plug, the earthing connection unit shall be connected before connecting the conducting pin.
(f) Pilot contact shall be provided in all high voltage plugs to maintain safe circuits. At least three pilot contacts are required in a single phase plug. When two or more cables are laid, interlock shall not be removed until all the cables are connected.
(g) While high voltage shore circuit breakers are open, the high voltage flexible cable conductor shall be maintained in the earthed condition manually or automatically. The pilot contact assembled in the high voltage plug and socket may be used for this interlocking application.
(h) Connection shall be made according to the following procedure:
(i) Connection
(1) Earthing connection (2) Power circuit connection (3) Pilot connection
(ii) Isolation
(1) Isolation of pilot connection
Shall be isolated before the required protection performance is lost.
Chapter 4 Requirements for High Voltage Shore Connection Systems 4.2 Requirements for Equipment
CR Classification Society GUIDELINES FOR HIGH VOLTAGE SHORE CONNECTION SYSTEMS GD-HVSC-202004 - 16 -
(2) Isolation of power circuit (3) Isolation of earthing circuit
(i) In principle, all the electrical and mechanical specifications of the high voltage plug and socket shall be according to IEC 62613-1 and -2; however, if the specifications on the shore side are different, then those specifications may be applied.
(j) The connection of the high voltage plug and socket shall be supported such that the cable weight does not fall on it.
4.2.9 Transformer
(a) A transformer when installed shall comply with chapter 7 and 14 in Part VII of the Rules for of Steel Ships.
The current of high frequency harmonics shall be considered when deciding the rated capacity of the transformer.
(b) Protection of transformer
The transformer shall be protected from short circuits and overloads. Time and current shall be considered when setting the values for overload protection according to the thermal capacity of the transformer.
(c) Shore system and shipboard distribution system shall be separated by an insulating transformer. An on -board transformer may not be required if the earthing arrangement for neutral is the same on ship and shore and an insulating transformer is provided on shore.
(d) If necessary, procedures shall be established for reducing the transformer inrush current, inhibiting the start of large capacity electric motor, inhibiting connection to large capacity loads, and so on.
(e) Primary and secondary windings of the transformer shall be separate. Secondary winding shall be star configuration.
(f) The neutral point of a transformer shall be connected according to the earthing arrangement used in the main distribution system.
(g) If the transformer is connected to a low voltage distribution system, insulated winding shall be provided between the high voltage and low voltage systems.
4.2.10 High voltage cable
Fixed high voltage cable installed on-board shall comply with the provisions of IEC 60092-353 and -354. High voltage cables that are not fixed installations (i.e. high voltage flexible cable) shall comply with standards deemed appropriate by the Society.
4.2.11 Laying high voltage cables
(a) If it is unavoidable to pass high voltage cable through accommodation space, fully closed cable run shall be used.
(b) High voltage cables are not to be installed in the same cable tray as low voltage cables below 1 kV.
Chapter 4 Requirements for High Voltage Shore Connection Systems