Topic 7 - Lighting Maintenance

Question 1

Replacement cost formula

Answer 1

Number of lamps x cost of lamp x hours of use / life of lamp

Question 2

Labour cost for replacement formula

Answer 2

Number of lamps x labour cost x hours of use / life of lamp

Question 3

Electrical energy cost formula

Answer 3

Number of lamps x wattage x hours of use x kwh rate / 1000

Question 4

What makes up the total operating cost?

Answer 4

Replacement cost + Labour cost + Electrical energy cost

Question 5

Advantages of LED lamps

Answer 5

1. High efficacy
2. Long life
3. Durable
4. No warm up time
5. Not affected by low temperature
6. Directional
7. Excellent colour rendering
8. Environmental friendly
9. Controllable

Question 6

Disadvantages of LED lamps

Answer 6

1. Expensive
2. Must be well engineered
3. Poor quality drivers