Alternating 450V Supply

Question 1

Alternative 450V supplies

Answer 1

•There must always be a 450V supply.
•There are two sources of 450V if the motor generators are lost:
~converted diesel generator.
~Emergency generator.

Question 2

Converted diesel generator.

Answer 2

A 600V generator can be re-configured as a 450V generator.

There is a access panel in the rear of the switchboard.

Question 3

Converted diesel generator

Answer 3

•Inside the panel is a switch with four positions:

• 440V generator test.
• 440V generator.
• 600V generator.
• 600V generator test.

Question 4

Converted diesel generator

Answer 4

• The 600V supply breaker is opened

* This disconnects the generator from the 600V bus bar.

Question 5

Converted diesel generator

Answer 5

• The four position switch is placed to 440V generator test.
• The generator output is checked to ensure correct voltage and frequency
• The four position switch is placed to 440V generator.

Question 6

Converted diesel generator

Answer 6

• The diesel generator alternative supply breaker is closed.
• This connects the generator to the 450V bud bar.

Question 7

Emergency diesel generator

Answer 7

• Type 23 also has an emergency generator.

* Output of this generator is 270kW, 450Volts, 60Hz, 3Ø.

Question 8

Emergency diesel generator

Answer 8

• The output is connected to an emergency switchboard.

* This is done by an emergency generator supply breaker.

Question 9

Emergency switchboard

Answer 9

The switchboard:

• General appearance is the same as other switchboards.
• Functions in the same manner.
• Has the same general controls.

Question 10

Emergency switchboards

Answer 10

• The emergency switchboard connects 450V, 60Hz, 3 Phase to essential equipment in an emergency situation.
• Feeder breakers provide power to the essential services.

Question 11

Emergency switchboard

Answer 11

The switchboard supplies:
•Steering motors. 
•High pressure salt water pumps. 
•Surgery/sickbay. 
•Smoke clearance exhaust fans.  
•Portable pump sockets.