Unit 3, Assignment 2Please check your spellng before submitting. A spelling error may cause a question to be counted as incorrect. Copy the link below into a new window on your web brower to answer Questions 1 through 5 http://www2.dupont.com/ISCEON/en_US/products/ISCEON_MO99.html?src=gg_refrigerants_mo99#.U9gAieNdWE0
1. Two benefits of R-438A having hydrocarbons as a part of its blend are:
R-438A, R-422B improve results , R-507A, R-427A,
combines R-22 pressure-enthalpy characteristics with mineral oil compatibility, can be used in R-22 replacement over a wide range of evaporator temperatures, has been designed to closely match the pressure, temperature, enthalpy, and mass flow properties of R-22, has a 42%25 lower global warming potential (GWP) than R-404A,
3. If an ultraviolet light leak detector is used, the site of the leak will glow a # .
TRUE, FALSE, ,
restart and monitor for leaks, recover the R-22, replace critical seals, charge refrigerant,
5. When a technician knows that a leak is in a certain area, # are valuable to find leaks.
has a temperature glide of 6 to 7 degrees, has an ODP of zero, has a safety group classification of A2, is flammable,
6. MO99 is actually the long term replacement refrigerant known as:
it allows the system to remain clean longer, it helps in oil return, this makes it compatible with mineral oils, it is easer to locate a leak in a system with R-438A,
7. Refrigerants should be selected so that low temperatures may be obtained without going into a vacuum. Why is it important to not allow most systems to operate in a vacuum?
is a replacement for R-12 but requires retrofitting, uses ester based lubricants, uses lubricants that are compatible with those used with R-12 online quizzes , is used in automotive air conditioning,
8. For most R-22 systems, when retrofitting to MO99, after labeling the system with an MO99 retrofit label, all you need to do is:
has slightly lower working pressure than R-502, is near azeotropic refrigerant, has a small temperature glide, is a replacement for R-500,
9. Refrigerants must be readily detectable. The first thing to do to find a leak is:
is an interim replacement refrigerant, is a refrigerant blend, is a replacement for R-22, is not a direct replacement because retrofitting is required ,
is a near-azeotropic refrigerant, is a retrofit replacement for R-22, has a large temperature glide and fractionation potential, is a good choice if the condensing unit is being replaced,
11. When using the compound gauge to read pressures below atmospheric pressure the readings obtained are:
replaces R-22 in residential and commercial air conditioning applications, has a very small temperature glide, has much lower operating pressures than the refrigerant it is replacing, should never be added to a system manufactured to operate with R-22,
12. An # leak detector detects leaks by sounds.
is used with polyol ester lubricant, is used to retrofit equipment using R-502 and R-22, is a very close match to R-502, has a higher efficiency than R-404A,
13. MO99 has a significantly lower discharge temperature than R-22 which may prolong life of the compressor.
has a saturation temperature of 40 degrees F at 118.3 psig , is an HCFC, has a light green cylinder, has a safety rating of A1,
14. R-22, R-502, R-12 and R-500 are long term replacement refrigerants.
is NH3 (ammonia), is not an HFC, CFC or HCFC, has a yellow cylinder, has a B2 safety rating,
TRUE, FALSE quiz builder , ,
use soap bubbles, use a halide leak detector, to listen for the leak, use an electronic leak detector,
17. An electronic leak detector can detect leaks as small as a # per year.
ultrasonic, , ,
soap bubbles,soap,bubbles, results , ,
quarter of ounce,quarter ounce,quarter of an ounce, , ,
bright,yellow,green,bright yellow green, , ,
psig, psia, inches of mercury vacuum (in Hg vacuum), none of the above,
22. What refrigerant that is being phased out in 2020 does DuPont’s MO99 refrigerant replace? (see the website)
directly relates to system capacity, is the number of pounds of refrigerant vapor that is circulated per unit of time, has to do with the amount of refrigerant circulated to the work accomplished, is an obsolete term,
23. lb/min (pounds per minute) of refrigerant
If a leak occurs, air is pulled into the system., System capacity is greatly reduced in a vacuum., Oil return is prevented.,