things we wont let tyre touch
a decrease in superheat causes the thermostatic expansion valve to begin to
close
in the evaporator
latent heat is transferred from the refrigerated spce to the refrigerant
a sight glass would normally be located
in the liquid line before the metering device
a liquid-to-suction heat exchanger is often used to
increase liquid subcooling
the flow rate of a TEV used in a r410A systems as compared to r-22 systems is
approximately 15% greater
a rise in evaporator pressure causes the automatic expansion valve to begin to
open
a liquid line filter drier should be placed between the
condenser and the metering device
bubbles in the sight glass could be an indication of
a refrigerant blend with a high temperature glide
the oil pressure safety switch is operated by
the difference between crankcase pressure and oil pressure
when using an electronic leak detector, the sensor probe
should be moved at approximately 1 inch per second
a thermal-electric (solid state) expansion valve is controlled by
NTC thermistor
a temperature differential across a filter drier indicates
a restricted filter drier
which of the following symptom(s) would be indicative of an oil logged condenser
high discharge line pressure and low liquid line pressure
a low pressure cut-off switch is used for
establish a minimum operating pressure in the evaporator
moisture in a refrigeration system will cause
compressor failure
in a direct expansion (DX) evaporator system, the refrigerant enters the evaporator as
mixture of liquid with some "flash gas"
a liquid reciever is used to
store liquid refrigerant
which of the following is true of a solenoid valve in a pump down system
it is located after the metering device
it is used instead of a metering device
it is located before the metering device
it is located after the evaporator
it is located before the metering device
a partially iced over evaporator can be caused by
an undercharge
what type of gauge is used to measure microns?
an electronic vacuum gauge
condensing unit and the latent/ sensible loads
an accumulator is used to
prevent liquid refrigerant from reaching the compressor
the purpose of an evaporator pressure regulating valve (EPR) is to
prevent evaporator pressure from falling below a set limit
_____ can be used for leak detection with ALL high pressure refrigerants
soap bubbles
in order to remove as much moisture as possible from a system
triple evacuate the system to 500 microns with a deep vacuum pump
water will vaporize at ______ temperature in a 28 HG vacuum
100 degrees
before a vapor/compression system is opened for service
the refrigerant must be recovered using approved equipment
back seating a two way service valve results in
closed service port with normal system flow
when topping of an operating system containing a blended refrigerant
introduce the refrigerant as a liquid into the low side using a throttling valve
a partially clogged capillary tube can cause
a starved evaporator