Wiring Systems and Enclosures - CABLE TRAY
Cable Tray systems, limitations, design, regulations, siting, cables, accessories, protection - 8 questions from a bank of questions
Answer ALL questions. Look for any feedback given if you get an answer incorrect. Keep choosing an answer until you get it correct. CORRECT or INCORRECT answers are indicated at the TOP of the page. A score is given at the TOP of the page when the exercise has been completed. © K.Brown 2015
why should cut edges of cable tray be 'made good' ?
- to minimise risk if damage to conductor insulation
- it makes fitting the cable tray together easier
- it helps maintain tray strength
- if makes to finished installation look better
what is the name of the 'pattern' of holes/slots in cable tray ?
- admiralty pattern
- standard pattern
- admirable pattern
- naval pattern
which one of the following 'finishes' would require an additional coating to ensure protection against corrosion ?
- red oxide
- PVC
- galvanising
- stainless steel
why is cable tray NOT to be used as an 'earthing conductor' ?
- because electrical insulation cannot be guaranteed
- because electrical continuity cannot be guaranteed
- cable tray CAN be used as an earthing conductor
- because cable tray cannot conduct electricity
what is the function of a 'return flange' on cable tray ?
- it provides strength to the tray
- it allows extra fixings to be made
- it allows the tray to be fixed to the wall
- it provides attachments for the cables
why is it important to provide spacing behind cable tray fixed flat to a wall ?
- to provide rigidity
- to allow cable-ties to be used
- to make the tray easier to fit
- to help keep the tray straight
which one of the following is a disadvantage of a cable ladder-rack system ?
- price
- adaptability
- ease of erection
- available in a range of sizes
what type of tray may be used for carrying large power cables in a factory environment, due to its exceptionally high strength ?
- ladder rack
- standard tray
- uni-strut steelwork
- cable basket