Part B Exam - Unit 8

What are the 4 types of luminaires?

Recessed troffers

Ceiling mount wraparounds

Open reflectors

Structural lighting

Recessed troffers are \___________ that distribute light.

Prismatic panels

Recessed troffers are commonly used for general lighting in:

Offices and commercial interiors

Why can recessed troffers sometimes appear excessively bright?

Because of the numerous troffers required

Ceiling mount wraparounds consist of \___________ mounted directly on the ceiling or wall.

Fluorescent fixtures

What is the purpose of the open reflector?

It partially screens lamps from view

The open reflector is typically used for:

Industrial installations or storage areas

Structural lighting is fitted into \_____________ of a room.

Architectural components

In incandescent light, an electrical current passes through a \_________ wire filament.

Tungsten

Why are incandescent light bulbs fading into obscurity?

Because of its low ratio of energy to luminous efficacy

What's the purpose of a vacuum or inert gas in incandescent light bulbs? (3)

Prolongs filament life

Reduces evaporation

Prevents oxidation

What is the main reason for a coated glass over the incandescent light bulb?

To distribute the light evenly

The fluorescent light bulb is filled with \________ instead of tungsten.

Mercury vapour

What does the straight tube fluorescent bulb need in order to work?

External ballasts

A high-intensity discharge light produces light when:

An arc passes between two tungsten electrodes

What is the purpose of gas in a tube for the high-intensity discharge?

To assist the formation of an arc

Why does a high-intensity discharge light require ballasts?

To supply adequate starting current

What applications is the high-intensity discharge light used for?

High ceiling applications

The low pressure sodium vapour light contains a small amount of:

Neon and argon

The high pressure sodium vapour light contains:

Xenon

Where are the low and high pressure sodium lights used?

Where intensive lighting isn't needed

What is the LED light's only disadvantage?

Its initial purchase cost

Low-voltage switching is characterized by:

Centralized control, and ability to control lighting at multiple locations

What happens if you use circuit breakers as switches?

It causes them to trip prematurely

The photoelectric controls are placed in series with the:

Holding coil of a normally closed relay

Electro-mechanical timers may be equipped with \__________, which are kept wound up by the electric clock motor.

Carryover springs

Infrared detectors only receive a signal from within:

A line of sight

What are important factors for occupancy sensors?

Area coverage and beam pattern

A dimmer diverts some of the current through a:

Variable resistor (rheostat)

What are some occupancies requiring emergency lighting? (9)

Assembly

Educational

Health care

Detention and correctional

Residential

Mercantile

Business

Industrial

Storage

What must emergency lighting be powered by?

A battery or standby generator

How can lighting and air conditioning improve the ceiling's appearance?

By eliminating air diffusers and air grills

How can high-efficiency ballasts reduce energy consumption?

Decreases wattage losses within the steel core and copper windings

Reduced light output ballasts reduce the amount of current to the lamps as much as \____%.

20

Which type of ballasts use much less power than conventional ballasts?

Solid state ballasts

The most economical time to relamp can be predicted based on:

The known rate of burnouts

The most economical group relamping period is about \____% of rated life.

70

How often are lighting systems cleaned?

Every 1-3 years

Most municipal water systems distribute water at pressures between _______________, with extremes of ______________.

350 to 490 kPa

175 kPa to 560 kPa

Why do some local regulations require that a higher pressure be available?

For fire protection

The water demand load is determined by adding up the maximum flow rate of:

All the plumbing fixtures in the system

In the direct pressure system, water is obtained directly through a municipal distribution system at approximately \_____ kPa.

350

In what instances is the tankless constant pressure system used?

When building demand is less than the max flow, or if the supply pressure is too low

Water for the building fire system comes directly from the:

City water supply

When two water pumps are used, each must be capable of supplying \____% of the max flow demand.

70

When three water pumps are used:

Two pumps must be capable of supplying 55% each, while the third is 25%

When must the constant pressure system with suction tank be used?

If water flow is not adequate to meet max demand

In the constant pressure system with suction tank, why must the pump suction always be above the bottom of the tank?

To prevent sediment from being discharged into the system

When must the constant pressure system with pneumatic tank be used?

When the water demand exceeds the supply, or source pressure is insufficient

How does the controller (of the constant pressure system with pneumatic tank) operate the service pump intermittently?

By measuring the differential pressure between the air space and the point of minimum water level

Use of the constant pressure system with pneumatic tank is limited to:

Smaller buildings

Downfeed systems provide storage capacity for potable water systems if:

Supply flow is too low

Where is the downfeed system storage?

Above the highest fixture in the building

Why is domestic water drawn off from the downfeed system?

So a reserve of water is always available for fire protection

How is the heater of a downfeed system maintained at a constant pressure?

Water supply to the heaters is drawn off near the top of the vertical supply line

The non-circulating hot water system is used where:

Only short runs of piping are required

Building regulations prohibit single pipe systems over \________ long.

15 m

Circulating hot water systems can be applied to buildings where:

Fixtures are a long distance from the central heating source

In what situations may fixtures be used alongside automatic air vents?

If the risers end below the top floor fixtures

An automatic gas-fired storage heater is an example of a:

Direct hot water heater

A \____________ in the flue increases heat transfer efficiency in hot water heaters.

Spiral baffle

In direct hot water heaters, why should the circulating pump be installed at the heater inlet?

Since heaters are used where there is a continuous demand

Why is there a mixing valve located at the hot water outlet of direct hot water heaters?

To maintain a safe temperature at the water fixtures to prevent scalding

In indirect hot water heaters, steam flow to the heater is controlled by:

A thermostatically controlled regulating valve

The use of a thermowell permits:

Removal of the bulb without draining the heater

The pressure relief device is most often installed in the:

Hot water discharge line

There must not be any valve installed between:

The relief valve and the heater

The drain line from the relief valve must never be connected directly to:

Any drain or vent pipe

Why is a fusible plug an unsatisfactory protection device?

Because water continues to flow until a new plug is installed

The temperature relief device must be located:

At the top of the tank or in the hot water outlet

What are the different types of backflow prevention? (5)

Air gap backflow prevention

Reduced pressure

Double check valve

Pressure vacuum breaker

Atmospheric vacuum breaker

To prevent even a small amount of waste from flowing back after flushing, a \_________ is installed below the flush valve.

Vacuum breaker

What is the difference between the reduced pressure principle device and the double check valve device?

In the reduced pressure principle device, there is a pressure differential relief valve between the two check valves

In the double check valve device, the check valves close if:

The upstream pressure is less than the downstream pressure

The pressure vacuum breaker consists of a single body which contains:

A spring loaded check valve

The atmospheric vacuum breaker consists of a moving element that:

Prevents water from spilling from the device during flow

Permanent protection of the storage heater is assured by lining the shell with:

Cement

A faucet leak is generally caused by:

A worn rubber washer

If a faucet leaks for an extended period of time, the faucet seat is most likely:

Rough

If a specific packing cannot be obtained, valve stem packing made of \_____________ can be used.

Cotton saturated with graphite

Some newer faucets do not use packing, but instead use:

A rubber O-ring

To resist corrosive action, some ball cocks are made of:

Vitreous china

The filler tube on the ball cock is often called the:

Hush tube

To prevent cross connection in toilets, adjust the float rod so that:

The water level does not come above the ball cock

Newer toilet installations are to be between \_________ per flush.

3.8 to 6 L

To solve condensation on a toilet tank:

Attach an inner liner, or a tray under the tank

Why was the piston type flush valve developed after the diaphragm type?

Because of frequently ruptured diaphragms

Soil pipes carry ____________ waste, while waste pipes carry waste from _______________.

Solid and liquid

Anything other than a toilet

All horizontal branch piping should maintain a minimum flow velocity of:

0.6 m/s

What kind of drainage system requires piping to only be partially filled with waste and water?

Horizontal branch piping

The slope of the horizontal branch piping depends on the \_________ of the piping.

Size

Drainage traps should be installed externally in the:

Discharge piping

Drainage traps should be within \______ mm of the fixture.

610

Deeper drainage traps are more resistant to ___________, but more prone to ____________.

Siphoning

Plugging

Why are stack vents usually oversized in colder climates?

Because of ice accumulation

All loop air vent piping in drainage systems should be:

Sloped

In drainage systems, why might the vent stack be connected to the waste stack?

So the pressures equalize

What are some materials that are often used for drainage pipe material?

Cast iron, galvanized steel, and copper

Cast iron drainage pipe joints may be caulked with:

Oakum

Which drainage pipe materials are used for drainage, venting, and waste discharge?

Copper and plastic