Questions exam

Question 1

With regards to the EWR act 1989 how do we comply with reg 13?

Answer 1

“Dead”
* LOTO
* Ph to Ph & Ph to earth
* Follow safety protocol

Question 2

What documentation does the RN use to comply with regs?

Answer 2

• HASAWA 1974
• EWR 1989
• BR 167 (SHE)

Question 3

What are the reqs for carrying out load trails?

Answer 3

• Load barge
• laptop
• generator isolated
• Trails form D346f

Question 4

State the purpose of the NER on ships

Answer 4

Limit fault current to acceptable limits 10A

Question 5

Why are we limited in the number of ACOS fitted?

Answer 5

• Weight
• Cost
• Throw over limit

Question 6

The thyristor converter provides 2 DC supplies what are they & what are they used for?

Answer 6

• 750 DC, 2250A -armature
• 270V DC 42.5A -Field current
  transfers power from AC to Dc & DC to AC

Question 7

What is the principle operation of cathodic protection?

Answer 7

2 dissimilar metals are in SW and connected together ,current flows from the more reactive metal (anode Hull) to the less reactive (Cathode). A basic galvanic cell. Protects hull from corrosion

Question 8

Name 2 types of fire

Answer 8

• Slow (slow to ignite & very smoky)
• Fast (flames very soon after ignition)

Question 9

Name 4 types of detector heads

Answer 9

• Optical
• ionisation
• Heat
• Infra-red

Question 10

Name advantages & disadvantages of AC induction motor

Answer 10

+ Easier to gen
+Variable output
+ Cheaper
- Slow to respond to load changes

Question 11

What actions should be taken in the event of supply failure?

Answer 11

• Check supply has failed
• Change to alternate supply
• Report loss to HQ1

Question 12

As I/C of EL repair team what are the tasks when closing up for action?

Answer 12

• Organise team
• Delegate tasks
• Prioritise tasks
• Comms
• Test equipment
• Training

Question 13

List the PPE worn when working on batteries

Answer 13

• PVC Apron (White)
• Rubber gloves
• vent fans
• Eyewash

Question 14

With regards to reg 14 how do we work on live equipment?

Answer 14

• Only if MEO is satisfied there is no alternative
• Person has been trained & briefed
• Sentry
• Avoid direct contact with any circuit or component which might be live
• No direct contact with any earthed metal
• Insulated tools
• Rubber mat
• Not when ship is moving

Question 15

Harmonic pollution causes what problems?

Answer 15

• Heat
• V distortion
• Zero crossing noise
• Unbalanced line current

Question 16

SACE breakers can be operated in what 2 methods?

Answer 16

• Auto
• Manual

Question 17

List the typical converted supplies

Answer 17

• 24V DC
• 50V DC
• 115V 400HZ
• 200V,400HZ

Question 18

static frequency changer

List the SFC fault protection

Answer 18

• Output V exceeds 126.5v (10% over)
• Power module Temp exceeds 120
• Load current exceeds 10.2A (130%)

Question 19

List safety precaution when serving batteries

Answer 19

• No smoking
• PPE
• Vent fans
• Face visor
• PVC Apron (white)

Question 20

2 procedures for monitoring Cathodics?

Answer 20

Dailies ,monthlys

Question 21

Describe how AC induction motor works

Answer 21

• 440 v 3 ph supply to windings
• Creates rotating mag field
• Conductor moves through mag field & induces EMF
• The 2 mag fields interact creating torque on rotor

Question 22

On a T23 what size is the emgen & what does it supply?

Answer 22

• 250KW
• 2 of 5 HPSW pps
• Emergency lights
• Sickbay
• Smoke clear fans
• Portable pp sockets
• Steering gear

Question 23

What controls the timing in auto for a siren?

Answer 23

Capacitors (C1,C2,C3 ect…)

Question 24

Reg 8 states the requirement to earth equip to prevent danger in a fault situation,what process controls the checking & testing of these earths?

Answer 24

• Umms
• Check for 0.1 ohms

Question 25

How is cooling on a generator achieved?

Answer 25

• Air/water heat ex (closed air circuit water cooler)

Question 26

Generator cooling in emergency?

Answer 26

• Open vent flaps on generator to allow air to flow through