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68 Cards in this Set

  • Front
  • Back
Do you need labor charge for a job is $45 in parks amount 1750 with a sales tax for the 7.25% what is the total for the job ticket
Sixty three dollars and 77 cents
The Apprentice registration is good for
One year
Determine Mechanical Code standard used in Oklahoma is the
2009 International mechanical
Do you like to know at requires that each employee inform employees about hazardous materials, this information may be found in
Material safety data sheet
type 1 refrigerant certification allows the repairman to work on
Small appliances
The flow of which free particles causes electric current flow
Electrons
What is the source of voltage that operates a potential relay
Back EMF
if a 240 watt lamp draws amps at 120volts, what is its resistance
60 ohms
When using a VOA meter connected across the load, what will the meter read with power applied
Voltage
All of the current passes through each load in circuits which are wired in
Series
The principle of creating a voltage in a coil due to a changing magnetic field is called
Inductance
What diagram is used to physically locate the components in a system
Pictorial
How many amps can a 40 VA transformer operating a 24 volts to carry
1. 66
0 ohm reading across contacts indicates close,what does an intermediate reading across contacts indicate
Burned contacts
A step-down transformer has a primary of 1000 wraps and a secondary of 250 wraps. What is the turn ratio
4:1
The start winding on an electric motor has
Greater resistance Than the run winding
In a multi speed motor the run capacitor is wired in series with
Start winding
Internal motor protection is provided by a
Thermally activated device in the motor windings on
The frequency of alternation current used in the United States is
60 Hertz
When replacing an outdoor fan motor, it is recommended that the following component also being replaced
Run capacitor
What instrument is used to check the alignment of two pulleys
Straight edge
When troubleshooting a positive temperature coefficient (ptc) relay, with the relay cool a good PTC relay will
Show continuity on an ohm meter
3 phase motors have
No star windings r capacitor
Two types of fans are the propeller and
Forward curve centrifugal
When a thermostat has RC and RH come you should install a jumper wire from.
RC to RH
As the length of gas pipe increases the pressure drop
Increases
What is the purpose of purging with dry nitrogen while brazing
alleviate oxidation
Steel pipe fitting which consist of female threads at each end for connecting two pieces of pipe of the same outside diameter is a
Coupling
Before applying cement to a cpvc joint ,you should apply
Primer
The maximum horizontal spacing between supports specified in the IMC for PVC pipe in
4 feet
When the drain heater in a low temperature system is functioning properly condensate collected in the drain pan will
Evaporate
If condensate from the inside of the low temperature box freezes in the drain pan the installer may need to install a
Heater
In gas piping, the point of delivery is the outlet of the
Service meter assembly
What 2 major gas fittings or components must be install outside the furnace cabinet
Cutoff valve and union
Black iron is used for what types of lines
Natural gas
To join PVC pipe to PVC pipe requires cleaning and
Cementing
Were part of a natural gas piping system is to be closed, it first must be tested by filling with
Air or inert gas
If a natural gas piping system fails a pressure test, you should pressurize the system and check for leaks with
Soap and water
Domestic clothes dryer ducc shall not exceed maximum length of
25ft
An early distribution system consists of a
Fan blower, supply and return ducts
A type B gas vent is
Double walled
Stove pipe and chimney fire may result from
creosote buildup
Latent heat involves
Change of state
Which of the following refrigerants does not contain chlorine
R - 134A
What is the evaporation temperature of r22 and 69 psig
40 degrees Fahrenheit
All of the following could be used to measure vacuum except
Psychomotor
What is the minimum acceptable level of evacuation for field installation of an AC system
1000 microns
When the heat loss of a structure equals the capacity output of the system
The balance. Has been reached
The difference between the condensing temperature of the refrigerator and the liquid line temperature is
Subcooling
The reason a heat pump must have a complete charge of refrigerant in it before the reversing valve may operate correctly is that if it's low on refrigerant
The system will have an insufficient pressure to move the main valve
What component should be energized 24 to 36 hours prior to start up the AC system
Crankcase heater
One common indication of the location of refrigerant leak is
oil on refrigerant components
Which of the following types of refrigerant systems could operate in a vacuum
Low temperature
Which component protects the compressor from liquid refrigerant
Accumulator
What happens to the TXV valve operation when the power element loses its charge
The valve opens
When pumping down a refrigeration system that has a liquid receiver which valve should you front seat
King valve
The difference between the cut in and cut out setting of a high or low pressure control is called the
Differential
All of the following could be used to locate a refrigerant leak except
a hydrogen leak detector
What category of equipment will type 2 allow you to work on
High pressure appliances
A motor burnout will make it necessary to install a suction line filter drier into the compressor to protected from contamination in
Acid
What load calculation procedure is used to arrive at the size of the residential heating system
Manual J
Temperature rise of a gas furnace is the combination of
Input and airflow
When measuring LP gas pressure on a furnace, what is the normal operating pressure
11.5 in. W.c
The high limit control on a gas furnace
Shut the furnace down when the temperature in the furnace or flue becomes excessive
Turning the gas pressure regulator adjustsment screw counter-clockwise will
Decrease input
A direct spark ignition (DSi) system is designed to
Providing ignition for the main Burners
Cracks in heat exchangers are caused by
Expansion and contraction
What component must be cycled off in the defrost mode
Outdoor fan motor