Ship's Power

Electrical Capabilities

• AC electrical power is generated by one of two 300 kw diesel-driven generators. Usually one generator operates at a time to provide all ship and scientific power. However, both generators may be operated for heavy load applications.
• DC power for the ship's electric winches is converted from AC by one of two silicon controlled rectifier (SCR) drive systems. The ship's bow-thruster power is provided by a separate DC power take-off from the main engine.
• AC power for scientific purposes comes directly from the operating generator, which also powers the ship's crane, winches, galley range, etc.

  
  

  Regular Service

  120 vac, 15 amp, single phase at several locations throughout the vessel, clean power at most dry lab locations.

  Special Service

  • 480 vac, 3 phase, 30 amp, 2 outlets
  • 480 vac, 3 phase, 50 amp, 1 outlet
  • 480 vac, 3 phase, 250 amp, 1 outlet
  • 480 vac, 3 phase, 400 amp, 1 outlet
  • 220 vac, 3 phase, 30 amp, 5 outlets
  • 220 vac, 3 phase, 100 amp, 1 outlet (for portable crane)
  • 120 vac, single phase, 30 amp, 4 outlets

• The following steps have been taken in order to improve the quality of electrical power for scientific electronic equipment:
  1. Provide electronic governors for ship's generators. This smooths out voltage and frequency fluctuations encountered when heavy equipment (crane and winches) are started or stopped.
  2. Installed specialized starters on ship's crane. This reduces the voltage and frequency variation introduced into the system when this equipment is started.
  3. Improved quality of electrical service on labeled laboratory circuits (30 KVA) by installing:
     • Transient limiting device to reduce the level of transient signals (spikes) reflected from other equipment on board ship.
     • Transofrmer (480 V to 110 V delta) which permits use of line filters common to most electronic equipment.
• Regulated power standards for research vessels were specified in the Feb. 1979 UNOLS Technology Assessment Committee (TAC) report as:
  1. Voltage - 5% acceptable variation
  2. Frequency - 2% acceptable variation
  These may not be the final standards, but will be used until further information is available. Electrical measurements of WECOMA voltage and frequency fluctuations follow in on this HTML page.
• Electrical power is available in most voltages and amperages normally used by scientific parties to a total of 50 kw. Users having special requirements should consult the Marine Superintendant in advance.

Electrical Measurements of Voltage and Frequency Fluctuations

Generator #1 (with new Electronic Governor)

• When starting Crane:
  • Voltage drop is -5% to -7%
  • Frequency is 59.8 hZ (.3% shift)
• When starting MG1:
  • Voltage drop is -3%
  • Frequency is 59.1 hZ (1.5% shift)
• When starting Crane:
  • Voltage drop is -6%
  • Frequency is 59.2 hZ (1.3% shift)

Generator #2 (with old Mechanical Governor)

• When starting Crane:
  • Voltage drop is -10% to -12%
  • Frequency is 58.1 hZ (3.3% shift)
• When starting MG1:
  • Voltage drop is -6% to -%8
  • Frequency is 57.05 hZ (5% shift)
• When starting Crane:
  • Voltage drop is -12% to -15%
  • Frequency is 57.05 hZ (5% shift)

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