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PE 4B > Unit 8 Plant Auxiliary Systems > Flashcards

Unit 8 Plant Auxiliary Systems Flashcards

1
Q

Luminaire

A

A complete lighting unit, including the lamp, a voltage controlling device or ballast and is the means of light control (reflector or refractor)

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2
Q

Luminaires provide

A

Direct or indirect lighting or a combination of the two

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3
Q

Four types of Luminaires

A

Recessed troffer, surface mounted wrap arounds, open reflectors, structural lighting

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4
Q

Recessed troffer

A

Rectangular light fixtures that fit in grids or recessed ceilings. They have Prismatic panels that distribute light. Commonly used for General lighting in offices and Commercial Interiors.

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5
Q

Ceiling mount wraparound

A

Fluorescent fixtures that are mounted directly on the ceiling or wall surface. Clear Prismatic plastic covers that surround the lamp. Give broad light distribution, inexpensive and efficient. May appear too bright in many installations

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6
Q

Open reflectors

A

Serve as Shields to partially screen the lamps from View. Used in industrial installations or in storage areas of commercial buildings

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7
Q

Structural Lighting

A

Fitted into Architectural Components of a room

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8
Q

Three main types of Illumination

A

General (uniform)
Local (supplementary)
Combined general/local

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9
Q

General illumination (uniform)

A

Designed to provide uniform illumination throughout an area. Used in most offices since it is difficult to predict the location of workstations, which require more lighting. Luminaires are spaced at regular intervals

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10
Q

Local or supplementary illumination

A

Used to illuminate work areas or displays regardless of the overall uniform ambient light.
Ex; track lighting that illuminates wall displays

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11
Q

Combined general/local (non-uniform or task lighting)

A

Provides reasonable lighting level. In addition an effort is made to identify specific work areas to increase their illumination levels. Requires more design work, but will be more energy efficient than a uniform system. More difficult to alter the lighting system if the room is rearranged

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12
Q

Direct lighting

A

All or most of the Luminous intensity is directed down, toward the work area

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13
Q

Indirect lighting

A

All or most of the Luminous intensity is directed up, at the ceiling. Light reflected off the ceiling, arrives at the work area indirectly

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14
Q

Direct lighting advantages and disadvantages

A

Advantages; more energy efficient, low initial cost, lower floor to ceiling height possible, easier to control and direct

Disadvantages; harsh Shadows, potential for direct glare, greater potential for ceiling Reflections and reflected glare, excessive luminance and glare

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15
Q

Indirect lighting advantages and disadvantages;

A

Advantages; potential for maximum Visual Comfort, greater glare control, Blends in with environment, produces uniform shadow free light

Disadvantages; less energy efficient, requires a uniform unobstructed reflecting sealing surface, increase in building cost, electrical installation may be more expensive

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16
Q

Incandescent light

A

One of the oldest developed light sources. Electrical current passes through a wire filament inside a glass bulb or globe. Filament glows and emits visible light

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17
Q

Main reason for coated glass

A

To distribute light evenly. Coding can also be colored

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18
Q

Halogen lamp

A

Type of incandescent light. Bulb is filled with halogen gas to prolong life of filament. Halogen provides a brighter light emission than typical incandescent lights. Operates at higher temperature then regular incandescent light.

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19
Q

Incandescent light luminous efficacy

A

Low ratio of energy to light emission efficiency. Most energy supplied to produce light is converted to heat.

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20
Q

Fluorescent lights

A

Type of gas discharge light source. Filled with mercury vapour. Electrical current is applied to the gas, producing ultraviolet light. The UV light then causes the phosphor coating inside the tube to Glow White. Consumes less energy than incandescent light.

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21
Q

Straight tube fluorescent light

A

All require external ballasts to work

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22
Q

Two types of compact fluorescent

A

Screw in and plug in. Both operate the same way as straight tube fluorescent lights

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23
Q

Screw in compact fluorescent light

A

Has an integrated ballast. Simply screws into existing electrical sockets

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24
Q

Plug-in compact fluorescent light

A

Requires a ballast and a socket that corresponds to a specific base configuration

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25
Q

High intensity discharge (HID)

A

Type of electric gas discharge light. Produces light when an arc passes between two tungsten electrodes inside a transparent quartz tube filled with metal salts and gas. Gas is used to assist with the Arc. Arc heats the metal salts that evaporate and form plasma. Can admit a large amount of light with relatively low energy consumption

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26
Q

HID primary uses

A

High ceiling applications. Like gymnasiums, warehouses and street lights. May require extended warm up time and not suitable for interrupted services

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27
Q

Mercury vapour light bulb

A

Type of HID light. Operates similar to hid but uses mercury vapour inside a pressurized glass tube coated with phosphor

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28
Q

Sodium vapour light

A

Type of gas discharge light. Similar to mercury vapour bulb except utilizes sodium gas inside a pressurized glass tube.

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29
Q

Two types of sodium vapour light

A

Low pressure and high pressure sodium

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30
Q

Light emitting diode (LED)

A

Semiconductor device that allows electric current to flow in One Direction only. Emit light when a suitable amount of electricity is applied across the leads. They have been steadily replacing other artificial light sources

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31
Q

High Luminous efficacy

A

Low energy cost with high ratio of energy to light emission efficiency

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32
Q

LED light disadvantage

A

The initial Purchase cost

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33
Q

Wattage

A

Amount of electrical energy consumed by the lamp to produce light

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34
Q

Lumen or luminous flux

A

Metric unit for total quantity of light emitted by a light source. The more lumens emitted by a light source, the brighter the light

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35
Q

Light colour is measured in

A

Units of absolute temperature (kelvin). Lower temperature light is more yellow. Higher temperature light is Bluer

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36
Q

Line voltage lighting system

A

Only uses line voltage rated controls and wiring. To control lighting it requires the use of 3-way and 4-way switches

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37
Q

Low voltage switching

A

Uses low voltage relays to control lighting from multiple locations

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38
Q

Low voltage switching advantages

A

Local and remote control of Lights, Reduction in installation cost, higher voltage lighting, alteration work is simpler, low voltage relays can be operated by programmed distributed control systems

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39
Q

Cadmium sulfide cell

A

Placed in series with a holding coil of a normally closed relay. As the illumination level drops, the resistance of the cell increases and the current through the relay decreases. When light level reaches the control setting, relay contacts close and light is energized

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40
Q

Timer for time clock

A

Device that energizes or D energized has a light out of preset time.

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41
Q

Two types of timers or time clock

A

Electromechanical or electronic

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42
Q

Electro mechanical time clock

A

Electric clock Motors that move a series of adjustable engagement dogs to turn the lights on or off at designated times

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43
Q

Electronic timers

A

Use microprocessor controls and switches to achieve the same result

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44
Q

Occupancy sensors

A

Turn the lights on when people enter a room, and off when they leave after a set time. Most effective in spaces with transient activities, where the lights are easily forgotten.

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45
Q

Occupancy sensors can reduce lighting costs by

A

20 to 60%. The sensors can pay for themselves in less than 2 years.

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46
Q

Areas where occupancy sensors are used

A

Conference and meeting rooms, hallways, washrooms, storage rooms, warehouses

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47
Q

Two most common types of occupancy sensors

A

Infrared and ultrasonic detectors

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48
Q

Infrared motion detectors

A

Respond to heat. They sense changes in patterns of heat radiated of objects warmer than their surroundings. Only receives a signal from within a line of sight

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49
Q

Ultrasonic motion detectors

A

Detect motion with ultrasound. Sends out an inaudible tone, capable of bouncing off walls and round corners. The returning tune is compared with the tone sent out. Any change in frequency indicate occupancy. Will turn on from any motion from person or object

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50
Q

When selecting an occupancy sensor, important factors to consider

A

Area coverage, beam pattern, and false triggering.

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51
Q

Infrared occupancy sensor disadvantage

A

May consider a mirrored image or daylight as a signal that space is occupied

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52
Q

Ultrasonic occupancy sensor disadvantage

A

May be triggered by vibrations

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53
Q

The most effective means of controlling the level of Illumination

A

By use of a dimmer

54
Q

Solid-state dimmers

A

Reduce the average voltage across the lamps by turning on or off at a particular instant

55
Q

Fluorescent and HID dimmers require

A

Special dimming ballast and special dimmers, not interchangeable with regular incandescent dimmers

56
Q

Emergency lighting must be powered by

A

Battery or a standby generator

57
Q

Emergency lighting must provide adequate lighting Within

A

10 seconds and remain on for 90 minutes

58
Q

In large Office Buildings the percentage of electrical energy consumption used by the lighting system

A

60%

59
Q

Energy savings can be gained by reducing the illumination levels

A

In areas adjacent to the task areas requiring higher levels of Illumination

60
Q

Lamp efficacy is expressed by

A

Lumens per watt

61
Q

Luminous efficacy is a pure ______

A

Ratio and expressed in percent

62
Q

The suitability of a lamp for a particular application is influenced by these factors
4

A

Life expectancy, colour rendition, cost, warm up time

63
Q

Energy saving lamps

A

Bulbs can be replaced with clear dummy bulbs that provide no light but allow the circuit to function normally. Used in areas with excess fluorescent light

64
Q

High-efficiency fluorescent ballasts

A

Decrease wattage losses within the steel core and copper windings. Can reduce energy consumption by 9%. Ballast life is two to three times longer

65
Q

Reduced light output ballast

A

Decrease energy consumption by reducing the amount of current to the lamps by as much as 20%

66
Q

Solid-state ballast

A

Use much less power than conventional ballast

67
Q

As interior surfaces become less reflective

A

The amount of energy required to illuminate a room increases

68
Q

Coefficient of utilization (CU)

A

The percentage of light that arrives on the work plane. Important consideration in an energy efficient installation

69
Q

Key points for maintenance in a lighting system

2

A

Relamping and cleaning

70
Q

Relamping

A

All lamps replaced at a pre-planned time. Usually done at 70% of rated life. Can mean a considerable amount of reduction in labour costs

71
Q

Dirty lights can drop light output by

A

5% per year. Cleaning is required from once a year to once every three years

72
Q

Most Municipal Water Systems distribute water at pressures between

A

350 kPa and 490 kPa

73
Q

In cases where tall buildings require higher pressure, _____ are used

A

Pumps

74
Q

Highest and lowest permissible pressure in Plumbing Systems

A

560 kPa and 175 kPa

75
Q

Water demand load for a building plumbing system is determined by

A

Adding up the maximum flow rate of the total number of Plumbing fixtures used in the system

76
Q

Two methods water may be distributed throughout a building

A

Up feed systems and down feed systems (gravity)

77
Q

Four common up feed water systems

A

Direct pressure, tankless constant pressure, constant pressure with suction tank, constant pressure with pneumatic tank

78
Q

Direct pressure system

A

Water is obtained directly from Municipal Distribution Systems at 350kpa. Water flows through a water metre in the basement and then through a horizontal water main

79
Q

Tankless constant pressure system

A

Used when supply pressure to a high rise building is too low to provide enough water pressure on the Upper Floor

80
Q

When two water pumps are used, each pump must be capable of supplying

A

70% of the maximum flow demand

81
Q

When three water pumps are used, two pumps must each have sufficient capacity to supply

A

55% of the maximum demand, and the third 25%

82
Q

In a two pump system, one pump is usually

A

In continuous service while the second is on standby

83
Q

Two situations where a surge or suction tank should be used

A

Water flow from the supply source is not adequate to meet maximum demand for building

Maximum building demand could cause water pressure in the supply source to drop too low

84
Q

During periods of extremely low water demand, a pressure relief device

A

Bypasses the flow back into the tank and prevents the pump from overheating

85
Q

Generally pumps are operated under low

A

Suction head and must be capable of providing a greater discharge head, this results in higher electric power consumption

86
Q

Pump suction should always be above

A

The bottom of the tank to prevent sediment from being discharged into the system

87
Q

Down feed or gravity systems

A

Have a storage or house tank above the highest fixture in the building. Provide storage capacity for the potable water systems in situations where the supply flow may be too low.

88
Q

Two methods of hot water supply systems for buildings

A

Non circulating hot water system and circulating hot water system

89
Q

Non circulating hot water system

A

Has a single pipe through which the heated water passes from a water heater to each fixture in the building.

90
Q

Non circulating hot water systems are normally used

A

In small residential buildings with short runs of pipe less than 15 m in length

91
Q

Circulating hot water systems

A

Have a return line connected near the end of each hot water main leading back to the water heater. Provides hot water at each fixture with shorter delays, resulting in less waste

92
Q

Circulating hot water systems are used

A

In all types of buildings where the fixtures are a long distance from the central heating source

93
Q

A circulating hot water system consists of these three things

A

A heater, Supply piping to carry hot water to the fixtures, return piping to return the unused water back to the heater

94
Q

A ______ must be installed in the return line

A

Check or backflow valve which prevents cold water from entering the hot water lines when there is maximum flow from the fixtures at the end of the hot water supply

95
Q

Two types of hot water heaters

A

Direct and indirect

96
Q

Direct hot water heaters

A

Water is heated by a burning fuel or an electric element

97
Q

Indirect hot water heaters

A

Heated by steam or high temperature water from a heating system

98
Q

Instantaneous water heater

A

Direct fired heater that does not require a storage tank because the water is heated instantly as it flows through the tubes.

99
Q

Aquastat

A

Thermostatic controlling device, regulates the ratio of the two Flows at the mixing valve. Maintains the proper hot water temperature.

100
Q

Temperature and pressure relief valves

A

Installed on the uppermost part of heaters. Release water pressure if the temperature of the water becomes too high due to malfunction of the system

101
Q

Temperature regulator

A

Consists of a bulb, capillary, and a valve actuator Bellows filled with a volatile fluid. Can be equipped with a thermowell to permit removal of the bulb without draining the heater

102
Q

Hot water system safety devices

A

Prevent dangerously High pressures and temperatures from developing in the system

103
Q

Hot water system pressure relief valve typically opens at

A

175 kPa or 25 psi above-normal line pressure

104
Q

Typically a relief valve is installed in the______

A

Hot water discharge line

105
Q

If water is heated to above 100 degrees Celsius in a pressurized system, it will become a super saturated liquid. If the water pressure is reduced,

A

The super saturated water will flash into steam

106
Q

Temperature relief devices open when the water temperature rises to about

A

99 degrees Celsius

107
Q

If the hot water system includes a hot water tank, it will be equipped with

A

A drain valve at the bottom. To remove excess scale deposits, two or three pills of water should be drained every two to three months

108
Q

High-limit energy cut off

A

Thermostat that shuts off the heat to the water heater when the maximum temperature has been reached

109
Q

Backflow

A

Backwards flow of water or other liquids and gases into the Distributing pipes of a potable water supply

110
Q

Backsiphonage

A

Caused by pressure that is below atmospheric in the supply system

111
Q

back pressure

A

Results from a downstream pressure in the piping system that is higher than the upstream or supply pressure

112
Q

Cross connection

A

Any actual or potential connection between the potable water supply and any other source or system through which it is possible to introduce contaminants into the water system

113
Q

Air gap backflow prevention

A

Physical separation between the free-flowing discharge end of a potable water pipe and an open, non-pressurized vessel

114
Q

Every Plumbing fixture in a building receives pure water and usually

A

Discharges it at some lower point

115
Q

To allow for inspection and maintenance, larger storage heaters are fitted with

A

Manholes

116
Q

Large hot water storage tanks and heaters are

A

Confined spaces

117
Q

Insulation maintenance for hot water systems

A

Checking and patching insulation on the heater, steam lines, and hot water lines, otherwise heat can be lost via

118
Q

Almost all faucet leaks are caused by

A

Failure to turn the faucet completely off after use, eventually the rubber washer inside wears out

119
Q

Hush tube

A

The filler tube on the ballcock. Extends almost to the bottom of the tank and reduces noise by preventing splashing

120
Q

Refill tube

A

Extends from the ballcock to the Overflow reseals the bull after Flushing

121
Q

To prevent cross connection

A

Adjust the float rod so the water level does not come above the ballcock

122
Q

Two types of flush valves

A

Diaphragm and piston

123
Q

Horizontal Branch piping

A

Used to convey waste from fixtures throughout a building to a waste or discharge stack. This piping must be designed so that flow is not interrupted

124
Q

In horizontal Branch piping, each branch connection to the discharge stack should have a

A

Long turn elbow that meets the vertical stack at an angle of 45°. Should maintain an adequate slope and size to maintain a minimum flow velocity of 0.6 metres per second

125
Q

Traps

A

Their purpose is to seal the outlet of a fixture from the drainage piping so that sewer gases do not enter the building

126
Q

Clean out plug

A

Usually located at the bottom of a trap to clean it out

127
Q

Traps are often installed at

A

The end of a long length of horizontal piping before a floor drain

128
Q

In a hot water system, the pressure relief valve may be installed

A

Close to the heater or tank

129
Q

How often must backflow preventers be tested

A

Annually

130
Q

Ambient lighting can be improved by two types of lighting

A

Direct or indirect or a combination of the two

131
Q

In an indirect hot water heater, the thermostatically controlled valve is used to control

A

Steam flow. The valve increases steam flow when the water temperature drops below the desired value

PE 4B (8 decks)

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