Questions exam Flashcards
With regards to the EWR act 1989 how do we comply with reg 13?
“Dead”
* LOTO
* Ph to Ph & Ph to earth
* Follow safety protocol
What documentation does the RN use to comply with regs?
- HASAWA 1974
- EWR 1989
- BR 167 (SHE)
What are the reqs for carrying out load trails?
- Load barge
- laptop
- generator isolated
- Trails form D346f
State the purpose of the NER on ships
Limit fault current to acceptable limits 10A
Why are we limited in the number of ACOS fitted?
- Weight
- Cost
- Throw over limit
The thyristor converter provides 2 DC supplies what are they & what are they used for?
- 750 DC, 2250A -armature
- 270V DC 42.5A -Field current
transfers power from AC to Dc & DC to AC
What is the principle operation of cathodic protection?
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
Name 2 types of fire
- Slow (slow to ignite & very smoky)
- Fast (flames very soon after ignition)
Name 4 types of detector heads
- Optical
- ionisation
- Heat
- Infra-red
Name advantages & disadvantages of AC induction motor
+ Easier to gen
+Variable output
+ Cheaper
- Slow to respond to load changes
What actions should be taken in the event of supply failure?
- Check supply has failed
- Change to alternate supply
- Report loss to HQ1
As I/C of EL repair team what are the tasks when closing up for action?
- Organise team
- Delegate tasks
- Prioritise tasks
- Comms
- Test equipment
- Training
List the PPE worn when working on batteries
- PVC Apron (White)
- Rubber gloves
- vent fans
- Eyewash
With regards to reg 14 how do we work on live equipment?
- 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
Harmonic pollution causes what problems?
- Heat
- V distortion
- Zero crossing noise
- Unbalanced line current
SACE breakers can be operated in what 2 methods?
- Auto
- Manual
List the typical converted supplies
- 24V DC
- 50V DC
- 115V 400HZ
- 200V,400HZ
static frequency changer
List the SFC fault protection
- Output V exceeds 126.5v (10% over)
- Power module Temp exceeds 120
- Load current exceeds 10.2A (130%)
List safety precaution when serving batteries
- No smoking
- PPE
- Vent fans
- Face visor
- PVC Apron (white)
2 procedures for monitoring Cathodics?
Dailies ,monthlys
Describe how AC induction motor works
- 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
On a T23 what size is the emgen & what does it supply?
- 250KW
- 2 of 5 HPSW pps
- Emergency lights
- Sickbay
- Smoke clear fans
- Portable pp sockets
- Steering gear
What controls the timing in auto for a siren?
Capacitors (C1,C2,C3 ect…)
Reg 8 states the requirement to earth equip to prevent danger in a fault situation,what process controls the checking & testing of these earths?
- Umms
- Check for 0.1 ohms
How is cooling on a generator achieved?
- Air/water heat ex (closed air circuit water cooler)
Generator cooling in emergency?
- Open vent flaps on generator to allow air to flow through
