C&C All

Question 1

C&C= control and communications
Switchboard.
Intro.

Answer 1

• Controls main converted supplies.
• A converted supply is a supply that has it’s voltage and/or frequency changed before distribution around the ship.
• The only exception is 115V lighting and power supplies.

Question 2

Main low power batteries

Answer 2

• Maintain supply to important services:
   -W.E equipment
   -Diesel engine starting 
   -RICE rationalised internal coms    equipment. 
• Two voltages supplied:
   -24 Volts DC
   -115V, 400 Hz
STEERING GEAR

Question 3

Main low power batteries

Answer 3

• Batteries connected to positive and negative bus bars.
• Maintain supplies should the main power supply fail.
• Batteries constantly being charged.

Question 4

Conversion of supply

Answer 4

• Conversion from AC to DC is by transformer rectifier Unit (TRU).
• Rationalised Transformer Rectifier (RTR)
• The main difference is that the low power batteries are integral to the RTR.

Question 5

Earth testing

Answer 5

• Earth testing is conducted by a built in system.

* Both positive and negative sides of the batteries must be tested.

Question 6

Batteries

Intro

Answer 6

•The term ‘battery’ is often missused.
•A battery is a number of cells connected in series.
•The ‘battery’ used in a torch is actually a single cell.
However, in real life, it is referred to as a ‘battery’ and everyone knows what we are talking about.

Question 7

Batteries

Answer 7

•Batteries produce (via chemical action) and store electrical power. 
•They can be:
 -Portable
 -Static
•Batteries have a variety of uses:
 -Torches 
 -Watches 
 -hearing aids
 -cars/lorries

Question 8

Batteries

Categories

Answer 8

• Primary

- Secondary

Question 9

Primary batteries

Answer 9

Primary batteries/cells have four main characteristics:

• Not rechargeable
• Known as ‘dry cells’
• Once discharged they are thrown away.
• Normally small

Question 10

Prime batteries

Dry cell

Answer 10

A dry cell battery stores energy in an immobilised electrolyte paste, which minimises the need for water.
Examples:
Zinc-Carbon batteries and alkaline batteries.

Question 11

Secondary batteries

Answer 11

Four characteristics:

• Rechargeable
• Known as ‘wet cells’
• Require specialist recharging equipment.
• Variety of sizes (AAA up to very large)

Question 12

Secondary batteries

Answer 12

Wet cell the battery contains a liquid electrolyte such as sulphuric acid. A dangerous corrosive liquid.

Question 13

Battery capacity

Answer 13

• Capacity I’d measured in amps-hours
• The maximum amperage that can be drawn continuously until the battery is completely discharged.
• The amp hour rate if a battery is provided by the manufacturer.
• 100 amp-hours at the 10 hour rate will maintain a discharge of 10 amps for 10 hours.

Question 14

State of charge

Secondary bat

Answer 14

•Measure the terminal voltage of each cell in the battery.
•The voltage differences between a charged and discharge cell is as follows:
-2.1V full charged
-1.75V discharged
•The difference in charge is only 0.35V
Per cell.
•does not give good indication of the state of charge.
•An accurate check can only be accomplished by used if specialist charging/testing equipment. Harder with newer batteries as they are sealed so the cells can’t be accessed.

Question 15

Where can you find the battery’s capacity?

Answer 15

Supplied by the manufacturer.

Question 16

Define a converted supply

Answer 16

A supply that’s had it’s voltage and/or it’s frequency changed.