Hvac Ac115 Final Review

If a critically charged refrigeration system is overcharged, which of the following is a likely result?

The approximate condensing temperature for R22 on a 95 degree day is _______ and the head pressure will be ________.

If an air conditioning system is calling for cooling and the compressor is running but the indoor (evaporator) fan is not running, which terminal on the thermostat will the technician most likely check first?

A 120 volt / 24 volt control transfer has a VA read rating of 20. The maximum amperage the Transformer will put out is 0.8 amps. True or false?

Technician "A" says that while checking the windings of a compressor, a reading of 10 ohms or less from the common terminal to ground indicates that the motor is okay. Technician "B" says that the resistance of the start winding should always be less than the resistance of the Run winding. Which of the following statements is correct?

If the resistance of the Run winding decreases:

What voltage does a potential relay operate from?

When the compressor in a system using capillary tubes is sweating, it is a sign of:

On a 95-degree day, the R22 refrigerant pressure on the high side of a high-efficiency system should be about _______ psig.

The instrument to check for a short in the compressor motor winding is:

The best way to tell if a compressor discharge line is at the correct temperature is to grab a hold of it. True or false?

With a rise in outdoor temperature, the head pressure will rise. True or false?

Reducing the CFM through the evaporator will cause the head pressure to_________.

If the suction pressure of an R-22 air conditioning system is 67p Sig and the evaporator Outlet temperature is 51 degrees, what is the evaporator superheat?

What does poor air flow across the evaporator cause?

A high superheat reading in a system that has a TXV indicates the TXV is defective. True or false?

A normally open switch when closed will show:

After evacuation, refrigerant in the liquid form is normally put into the system through the:

If an air conditioning system is turned on but none of the major components (compressor, condenser, indoor fan) are operating, what is the first thing that a technician should check?

If line 1 of a circuit had a potential of 120 volts and line 2 has neutral, the potential voltage difference between Line 1 and line 2 would be 0 volts. True or false?

A technician needs to check a single phase compressor. He labels the three terminals a, b and c and takes resistance readings of the windings. He reads 10 ohms from A to B, Infinity from B to C and infinity from C to A. Identify the terminals.

If a motor hums but does not start, there is a potential problem with:

Three terminals in the compressor junction box are marked 1, 2 and 3. Using an ohmmeter, the resistance of the internal motor windings are: 1.5 ohms between terminals 1 and 2, 3.5 ohms between terminals 1 and 3 and 5 ohms between terminals 2 and 3. The common terminal is:

If an air-cooled condenser is located on a 95 degree roof and the condenser saturation temperature is 150 degrees, which of the following is a possible scenario?

As a rule of thumb, the air leaving the evaporator will be about ________ than the air entering the evaporator.

On a 85 degree day, the R22 refrigerant pressure for a high-efficiency condensing unit should be about ________ psig.

Problems in the refrigerant portion of a system are caused by:

If the metering device malfunctions and gets stuck in the closed position, the compressor could overheat. True or false?

Subcooling occurs in the evaporator as well as the condenser. True or false?

Reducing the CFM through the evaporator will cause the amount of moisture removed from the air to ________.

How would too much refrigerant affect the operation of a system with capillary tubes?

How does a dirty condenser affect a capillary tube system?

The most common cause for an evaporator to freeze is:

When working on an air conditioning or heating unit the technician always needs to remember?

When charging a system with Vapor refrigerant from a refrigerant cylinder the cylinder will become:

The term volt-ampere (VA) is used to:

The cooling anticipator in a thermostat is usually an adjustable type. True or false?

Technician "A" says that a shorted winding will result in an increase current flow through the winding. Technician "B" says if a motor is to be replaced a motor with a lower horsepower rating should always be used. Which of the following statements is correct?

An open winding in an electric motor means that:

If a condenser fan motor grounds out, it will usually:

Condensing units located outside that are required to operate year-round must have:

If a compressor motor locks up it will:

The liquid line temperature is used to determine the ________ of a condenser.

A typical evaporator superheat reading at the evaporator outlet for a central air conditioning system on a 95 degree day would be ________ degrees F.

If a compressor has a partially shorted winding, it could run for a while, overheat and shut off. True or false?

Reducing the CFM through the evaporator will cause the amperage draw of the compressor to ________.

Two types of fixed bore metering devices are ________ and ________.

In any fashion compressor is usually indicated by ________ head pressure and ________ suction pressure.

If a system is overcharged the discharge pressure will?

The use of fuses for troubleshooting is an acceptable practice. True or false?