What is meant by the term "detent"?

Line voltage thermostats have heavier contacts and use which type of sensing element?

To obtain an accurate reading of a fluid in a large pipe, a technician should ___

A low pressure control has a "high event" and a "differential" setting. The technician wants the system to turn on at 28 psig and shut down at 2 psig. WHt would be the proper settings?

If the suction pressure of a system is 60 psig and the oil pump outlet is 85 psig, what is the net oil pressure?

Oil pressure safety controls measure the difference in pressure to establish _____

To prove that the combustion blower motor is operating ignition, a _____ would be used.

Where would a water regulating valbe that is controlling head pressure be installed?

When a water regulating valve is used to control the head pressure of a water-cooled system, the valve's spring is acting against which pressure to modulate the water flow?

The expansion tank provides a means of removing the air from the system as well as _________.

A column of water one foot high exerts a pressure of ________.

The more common type of expansion tank is the _____ expansion tank.

The reason for using zone valves on a hydronic heating system is to _______.

Air in a hydronic system can cause __________.

A pressure relieg valve is set at 30 psig. The valve is contantly opening and flooding the floor. What is causing the relief valve to contantly open?

The limit control on a hot water boiler is need to ________

The pressure relief valve ______.

An expansion joint is a device used to ____________

A series of loop hydronic system is not desireable for use in a large residence because _________

In a series loop hyfronic heating piping system, ________

The evaporator of a chiller can be used to absorb heat from

Two basic categories of chillers are the _________-

A beenfit of operating a compressor unloaded is

A reciprocating compressor with six cylinders, three banks of two cylinders each, can have its capacity reduced by unlading to ____% of full capacity

Speeds up to ________ rpm are used in centrifugal compressors

A centrifugal compressor uses _______for capacity control.

Direct expansion evaporators have ________

The compressors used in low pressure chillers are the ________ type

WHen a chiller using a low-pressure refrigerant is operating, the low pressure side of the system _______

A purge unit __________.

If the blower on a cooling tower breaks down on a hot day, the ______

Heat that the cooling tower must reject from the water in the chiller is the cooling load of the conditioned area plus the heat

Cooling towers are designed to reduce the entering water temperature to within ____F of the air's wet bulb

When sizing a cooling tower, the tower is sized to handle the cooling load of the conditioned area plus about _____% for heat of compression

The term ________refers to the process of cooling the circulating conderser water by evaporating the tower water.

Natural draft towers and spray ponds are designed to produce a defference in water and are temperatures of ______F

Two methods used to aid the evaporation rate of water in a forced or induced draft tower are_______________

A blowdown system for a cooling tower _________

The purpose of the cooling tower bypass valve is to _________.

Two types of shaft seals used for centrifugal pumps are _____

The first steps to starting a chilled water system is to

There should be a ______ test point at the inlet and outlet of any water heat exchanger, chiller, or condenser.

A chiller field control circuit

Chillers manufactured in the last few years all have ______controls

Water-cooled chillers must have water treatment to _____-

Conterfugal chillers range in size from ____tons

A typical chilled water system is designed to operate with a leaving water temperature off the chiller coil of _____F

The ideal cooling tower temperature of a lithium bromide absorption system is 85 degree F. What is a likely result if this temperature drops to 75 F

The amount of refrigerant indicated on the ______is the total refrigerant charge for the unit not simply holding charge as in the case of a split type system.

The fans that move air through the air cooled condensers are of the ____ type.

The unit's location should be carefully selected so they system's operation is not adversely afffected by air being able to _______the condenser coil.

It is good field practice to double check and possibly triple check the ______decision, since the cost of repairing an improperly cut roof canbe very high.

If the curb is mounnted as part of a new construction process, it can be assembled and installed as soon as the _____ support system is in place.

It should be noted that, in most cases, the supply and return ductwork must be attached to the _______before the unit is set in place.

Be sure to provide proper and adequate support for the duct system according to ____________.

By tapping his fist on his ______, the crew member is telling the crane operator to use the main hoist.

With both fist in front of the body, pointing the thumbs outward tell the crane operator to _____ the boom.

__________ are intended to provide mechanical ventilation and also help reduce cooling costs by allowing outside air to be introduced to the conditioned space when conditions are correct.

The economizer is able to increase is able to increase or decrease the amount of outside air that is brought into the structure with two _______

The heat anticipator in a thermostat prevents the temperture inthe conditioned space from rising above the thermostat setting.

The cold anticipator starts the cooling system to allow the air-conditioning system to get up to capacity when needed

The advantage of using a thermistor-type thermometer over a mercury filled thermometer for measuring refrigerant line temperture is that the thermister-type does not have to be installed

A helix coil is used in some applications to sense temperature in a moving air stream

A dual pressure control is actually a low pressure control and a high pressure control connected in parallel with each other

Natural gas fired heating units operate at a manifold pressure of 3.5" water column

The more sections a boiler has, the higher its capacity will be

Expansion tanks must always be bled from the top until all of the air is removed from it.

Hydronic heat circulators are centrifugal pumps.

Automatic air vents rely on internal disc that swells when water is sensed.

The only place a bleed valve is needed is on top of the boiler.

It is possible for a hydronic system with many zones to operate with one circulating pump.

In a series loop, the water going through the last terminal unit will be the same temperature as the water through the first terminal unit.

A tankless domestic water system provides hot water from a coil in the boiler.

To unload a reciprocating compressor, hot gas bypass across the cylinder is the best method.

When referring to evaporators, the terms "direct expansions" and "dry type" can be used interchangeabley

High pressure chillers use either air or water cooled condensers.

Thermostatic expansion valves are the only metering devices used in high pressure chillers.

Low pressure chillers use either air or water cooled condensers.

Lithium bromide is ideal for use in absorption systems because it is non-corrosive.

Electronic starters are much smaller than conventional starters.

A well designed and installed cooling tower only requires a minimum of maintenance.

Distilled water is added to the cooling tower to make up for water lost during a blowdown.

The condenser water pump is the device that moves the water through the condenser and cooling tower circuit.

if vortexing occurs, it is an indication that there is not enough air in the tower.

The operation of these chillers involves starting running and stopping chiller systems in an orderly manner.

If the purge unit on a chiller is operating very frequently, the system may have a leak.

Low-pressure chillers operate in a vacuum and will stay in a vacuum if the equipment room is not warm enough to keep the refrigerant warm.

Package units are factory assembled, factory-charged, self contained systems that have all of the major system components contained in a single housing.

The rooftop unit houses the fans and blowers that move air through the heating and cooling portions of the unit but not through the condenser.

Although packaged air conditioning equiptment comes pre-charged with refrigerant and not field piping must be done, the installation of a rooftop package unit involves many steps and can be very dangerous.

Improper clearances do not affect the ability of service personnel to perform their job adequately.

Some roofs are bonded, which are roofs that carry a written warranty or insurance policy that protects the building owner in the event damage from leaks occur.

Curbs can be prefabricated but many larger curbs are shipped unassembled.

Gasketing materials and foam panels that are shipped with the curb are not part of the curb and should be discarded.

The curb's cross braces are inteded to support the duct connections to the unit but not the entire air distribution system

The term enthalpy refers to the total heat content in the air, which accounts for both the temperture (Sensible heat portion) and the moisture content (Latent heat portion) of the air.

By utilizing a strategy called demand control ventilation, DCV, the amount of outside air being brought into the building can be varied based on the actual occupancy level in the structure.

In order to deliver different volumes of aire to various areas in an occupied space, the blowers used on VAV systems must be able to modulare their opeings to accommodate the changing needs of the system.

When chemically cleaning a condenser, it is extremely important to properly flush the coil to prevent corrosion.