chapter 6- Electrical system

Question 1

What is electricity

Answer 1

The most costly and widely used energy source within the hospitality industry

Question 2

explain the electrical systems

Answer 2

• most hospitality operations have their electricity delivered by a local utility
• utility is responsible for providing power at a correct voltage and frequency
• utility provides power through an electric meter that measures the rate and amount of power consumed, this information is used to generate electrical bills

Question 3

what is voltage?

Answer 3

a measure of the electrical potential provided by the utility
(often compared with water pressure in a water system)

Question 4

what is frequency

Answer 4

the rate at which AC alternates direction of current flow

50/60 Hertz

Question 5

what is phases

Answer 5

the number of ‘hot’ wires in electrical system (1 or 3)

Question 6

what are feeders?

Answer 6

• deliver electricity to various portions of the building and to major equipment

Question 7

what are transformers

Answer 7

• devices that change the voltage of the electrical supply

step up or step down

Question 8

what are the design of operating standards

Answer 8

• Electrical distribution system at the property should be designed and maintained according to all relevant codes and standards
• these codes and standards ensure to provide safe and reliable sources of electrical power

Question 9

what are the codes and standards of system design and operating standards

Answer 9

1. National Electrical Code (NEC)
   concerned with safety
   provisions should be viewed as minimum standards
2. National Fire Protection Associations (NFPA)
   safety issues for employees operating/ maintaining a electrical systems are covered in the NFPA
3. Occupational Safety and Health Act (OSHA)
   legal requirements for electrical systems and safety are contained in the OSHA
   contains a large number of provisions for electrical safety

Question 10

what is needed for an effective electrical maintenance program

Answer 10

• current electricity system plans
• knowledge of electrical practices and buildings electrical system
• good housekeeping practices in areas containing electrical equipment
• proper safety procedures
  incorporation of electrical maintenance procedures into the facility’s preventive maintenance program

Question 11

what colour of wire is used for an equipment ground?

Answer 11

green or bare

Question 12

what colour of wire is used for your power source?

Answer 12

any colour but green, white or bare

Question 13

what causes a hermetic motor compressor burnout

Answer 13

moisture, high head pressure
single phasing on a three phase unit
start winding not dropping out

Question 14

how much voltage drop does it take to cause problems to a motor?

Answer 14

10%

Question 15

how many terminals does a domestic hermetic motor usually have? name them

Answer 15

1. Three
2. Start
3. Run

Common Neutral

Question 16

if a three phase motor is running backwards, what should you do to correct the problem?

Answer 16

Switch any two legs of power to the motor

Question 17

what are the operating practices to reduce electrical maintenance needs?

Answer 17

1. Keep electrical equipments clean
2. Store electrical equipment in dry locations
3. use a form grip when unplugging equipment
4. match equipment task
5. prompt reporting of malfunctioning
6. no DIY repairs to be allowed
7. Allow for proper access and air circulation in electrical rooms
8. Lock out/ Tag out procedures

Question 18

what are the key safety tips?

Answer 18

• When performing onsite excavations, refer to site maps for the location of any buried electrical cables
• avoid electrical service locations when painting eaves and drain troughs or doing other work on the roof/ sides of buildings
• Avoid downed electric wires
• Avoid any tree or limb touching electrical wires
• Wear safety glasses and rubber soled and heeled safety shoes when working

Question 19

what are the system components

Answer 19

• Fuses and and circuit breakers
• Distribution panels & wiring
• Electric motors, controls and drive elements
• electronic equipment
• Emergency power systems
• Electrical maintenance equipment

Question 20

electricity utility billing

Answer 20

• Electricity bill results bulk of utilities bill/costs
• energy = consumption
• charge = capacity

Question 21

what are the two utility charges

Answer 21

1. Energy (consumption) charge
   amount of electricity used by customer over the billing period
   kilowatt- hours (kwh)
2. Demand (capacity) charge
   based of the business’s highest rate of energy usage - kw

Question 22

what are the two types of electricity utility metering

Answer 22

1. Kilowatt- Hour meter
   - used to determine the number of kwh of electricity used
   - on a kwh meter, the meter fails are read in sequence from left to right
   - the number recorded should be the lower of two numbers that the hand is between each dail

2. Kilowatt- Hour Meter with Demand Meter 
• maximum demand 
• demand dails
• cumulative demand register 
• recording demand meters