NATE Industry Competency Exam: Commercial Refrigeration Questions With 100% Verified Answers.
6 views 0 purchase
Course
NATE
Institution
NATE
NATE Industry Competency Exam:
Commercial Refrigeration Questions With
100% Verified Answers.
With the condensing pressure and compressor speed remaining constant, a decrease in suction
pressure will cause a(n):
a. Decrease in compressor capacity and decrease in current.
b. Increase in compre...
NATE Industry Competency Exam:
Commercial Refrigeration Questions With
100% Verified Answers.
With the condensing pressure and compressor speed remaining constant, a decrease in suction
pressure will cause a(n):
a. Decrease in compressor capacity and decrease in current.
b. Increase in compressor capacity and decrease in current.
c. Increase in compressor capacity and increase in current.
d. Decrease in compressor capacity and increase in current. - answer✔D
An indication of non-condensable gas in a refrigeration system is significantly:
a. Lower-than-normal suction pressures.
b. higher-than-normal suction pressures.
c. Lower-than-normal head pressures.
d. higher-than-normal head pressures. - answer✔D
An automatic expansion valve controls refrigerant flow to an evaporator by maintaining a
constant:
a. Suction pressure.
b. Pressure differential across the valve port.
c. Liquid line pressure.
What is the approximate compression ratio of a compressor operating at 35 psig suction pressure
and 135 psig discharge pressure?
a. 1:03.
b. 3:01.
c. 1:04.
d. 4:01. - answer✔B
The BTUs rejected at the condenser are always greater than the heat absorbed in the evaporator
because:
a. The condenser is mounted outside with restricted airflow.
b. Of the high temperature of the discharge vapor and length of the discharge line.
c. Of the inefficiency of the condenser and pressure drop in the discharge line.
d. Of the heat of compression in the compressor. - answer✔D
A unit cooler is inspected and found to be completely iced up. The heaters and defrost timer are
found to be working properly. A technician should:
a. Adjust the defrost termination switch to a higher temperature setting.
b. Adjust the thermostatic expansion valve to a higher superheat setting.
c. Clear all of the ice from the coil and find out why the coil is frosted.
d. Increase the frequency of the defrost cycle. - answer✔A
what is the correct gauge pressure corresponding to an absolute pressure of 24.7 psia at sea
level?
For a lineup of medium temperature case, an evaporator temperature 0f 23°F is needed. The
following conditions exist:
· The suction line pressure drop is equivalent to approximately 2°F.
· The liquid line pressure drop is equivalent to 1°F.
The compressor capacity should be selected based on a saturated suction temperature of:
a. 20°F.
b. 21°F.
c. 23°F.
d. 25°F. - answer✔B
What is true of systems with multiple evaporators at different temperatures?
a. It is required to install evaporator pressure regulator(s).
b. The compressor discharge pressure will be a function of the coldest space.
c. It is required to install a head pressure control valve.
d. It is required to install a crankcase pressure regulator. - answer✔A
If charging a system by subcooling, what metering devices is installed?
a. Capillary tube.
b. Restrictor.
c. Thermostatic expansion valve.
d. Fixed orifice. - answer✔C
The most critical refrigerant line with respect to sizing for compressor performance is the:
a. Liquid line.
b. Discharge line.
c. Suction line.
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Brainbarter. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $11.49. You're not tied to anything after your purchase.
