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napoleon
07-12-2005, 08:25 PM
I am a stationary engineman in Quebec, Canada.
Recently, I wrote for my refrigeration certification.
In Canada, it is known as a refrigeration "B" class.
I would certainly appreciate some answers to a few
questions.

Q1 which one of the following is on the HIGH side?
a) evaporator
b) oil separator
c) condenser
d) liquid receiver

a is on the low side (obviously), but b, c, and d are clearly all on the HIGH side. Therefore, they are equally correct answers. There is an incompatibility issue concerning the questions and answers. What is one's opinion?

Q2 Does air (non-condensables) in the system cause
high discharge temperatures? Another answer supplied in the multiple choice was that it would increase the refrigeration system output.

Q3 What is the purpose of a cooling tower?
a) cool the condensate water OR
b) improve compressor operation (I selected B, because
a cooling tower helps reduce the condensing temperature/pressure, therefore the compressor discharge pressure is reduced. This minimizes wear and tear on the compressor (parts).

Q4 Would you say NH3 damages the environment more than butane, isobutane, chloride, methane (A3 group refrigerants)?

Q5 The suction filter on an air (reciprocating) compressor
is used to:
a) ensure a good suction OR
b) filter out dust and any foreign particles that can potentially contaminate the oil.

(I believe B is correct, because through the filtration of dust and foreign particles, not only does it help prevent the contamination of the oil, but it prevents that "dirt" from destroying the instruments in the field. (pneumatic valves can be negatively affected by such "dirt"). Answer a is simply too general. However, answer B clearly illustrates the suction filter's important use.

Thank you! I appreciate any feedback!

Napoleon

Abe
07-12-2005, 09:18 PM
Q1 which one of the following is on the HIGH side?
a) evaporator
b) oil separator
c) condenser
d) liquid receiver

a is on the low side (obviously), but b, c, and d are clearly all on the HIGH side. Therefore, they are equally correct answers. There is an incompatibility issue concerning the questions and answers. What is one's opinion?

Condenser is on HIGH side



Q2 Does air (non-condensables) in the system cause
high discharge temperatures? Another answer supplied in the multiple choice was that it would increase the refrigeration system output.


Will cause HIGH discharge pressure




Q3 What is the purpose of a cooling tower?
a) cool the condensate water OR
b) improve compressor operation (I selected B, because
a cooling tower helps reduce the condensing temperature/pressure, therefore the compressor discharge pressure is reduced. This minimizes wear and tear on the compressor (parts).


Cool the condensate water
ie: the warm water from shell and tube condenser goes thru the cooling tower and releases its heat.



Q4 Would you say NH3 damages the environment more than butane, isobutane, chloride, methane (A3 group refrigerants)?


Dont know


Q5 The suction filter on an air (reciprocating) compressor
is used to:
a) ensure a good suction OR
b) filter out dust and any foreign particles that can potentially contaminate the oil.

(I believe B is correct, because through the filtration of dust and foreign particles, not only does it help prevent the contamination of the oil, but it prevents that "dirt" from destroying the instruments in the field. (pneumatic valves can be negatively affected by such "dirt"). Answer a is simply too general. However, answer B clearly illustrates the suction filter's important use.



I believe you are right

napoleon
07-12-2005, 09:26 PM
Thank you Aiyub for the feedback! I appreciate it!
cheers

Napoleon

slingblade
07-12-2005, 09:55 PM
Those are some very odd questions indeed. take q. n1. the condensor, liquid receiver and oil sep are all on the high side. was there an option to indicate more than 1 answer? q. n5. what is a "good suction" ? does this mean correct pressure (and flow) for optimum system operation? they seem vague. also may i ask what is a stationary engineman? i am not familiar with this term.

thanks
s.

napoleon
07-12-2005, 10:27 PM
Those are some very odd questions indeed. take q. n1. the condensor, liquid receiver and oil sep are all on the high side. was there an option to indicate more than 1 answer? q. n5. what is a "good suction" ? does this mean correct pressure for optimum system operation? they seem vague. also may i ask what is a stationary enginman? i am not familiar with this term.

thanks
s.

Hello slingblade! I agree with you. The questions on my exam were quite odd and vague, as you put it. For question 1, there was NO other choice other than
a) evaporator b) oil sep c) condenser d) liquid receiver
b, c, d, are all equally correct. I also found the "good suction" bit quite unclear, as it does not properly relate to the question. That is why I selected the fact that a suction filter is used to filter out dust and any foreign particles from contaminating the oil. I doubt a suction filter would optimize the compressor's operation by controlling a "good suction" pressure. There are controls that ensure proper suction pressure setting. Do you think my answer (dust/particle filtration) is the better of the two?

Canadian technical language translates refrigeration engineer/technician to stationary engineman. Stationary implies that the engineer/technician works with stationary machines. Engineman is another synonimous term to engineer. Stationary (machines) Engineman (engineer); it also covers the occupation of boiler-man.
Hope this clarifies the canadian technical terminology.
thanks
napoleon

US Iceman
07-12-2005, 11:21 PM
(Q4) Would you say NH3 damages the environment more than butane, isobutane, chloride, methane (A3 group refrigerants)?

My answer would be NO. Ammonia has a zero ozone depletion factor and is environmentally stable.

napoleon
07-12-2005, 11:25 PM
Thank you US Iceman for the feedback!
Cheers
Napoleon

Abe
08-12-2005, 12:18 AM
I agree that both oil sep and receiver are on the high side

In the absence of being able to indicate all three on the answer sheet..............

I would gp for condenser first
Receiver 2nd and oil sep third

Im a bit unclear about oil sep as it has an in port on the high side, then an oil return point via the low pressure sump


Who knows what was in the mind of the guy who set the questions

But u cant go wrong putting down condenser coil

napoleon
08-12-2005, 12:24 AM
Thank you Aiyub for the feedback!
cheers

napoleon

Dan
08-12-2005, 01:02 AM
Stationary implies that the engineer/technician works with stationary machines.

Funny, in the states I always assumed it referred to the technician being stationary. Remaining at one job site to attend to the equipment, as opposed to responding to service and maintenance needs in various locations.

napoleon
08-12-2005, 04:38 AM
Hello Dan! You make a good point! Stationary also, definitely, indicates the fact that the engineman is to stay and monitor the refrigeration system. Oddly, here in Quebec, the francophones mistakenly believe that the term stationary relates to machines and humans. Quebecors label service technicians as stationary enginemen. The translation or terminology is misleading
given the nature of the work. This may be attributed to the language issue in Quebec.
thanks

Napoleon

slingblade
08-12-2005, 09:16 PM
I agree that both oil sep and receiver are on the high side

In the absence of being able to indicate all three on the answer sheet..............

I would gp for condenser first
Receiver 2nd and oil sep third

Im a bit unclear about oil sep as it has an in port on the high side, then an oil return point via the low pressure sump


I know, its six of one and half a dozen of the other. just to make matters worse, what side of the system is the expansion valve on? answers on a postcard please lol. most systems dont have an oil sep or receiver (domestic fridges) so i agree the condenser is the most common. also im glad i didnt sit that exam.



I also found the "good suction" bit quite unclear, as it does not properly relate to the question. That is why I selected the fact that a suction filter is used to filter out dust and any foreign particles from contaminating the oil. I doubt a suction filter would optimize the compressor's operation by controlling a "good suction" pressure. There are controls that ensure proper suction pressure setting. Do you think my answer (dust/particle filtration) is the better of the two?


Yes i do agree.


francophones

I think youll have to help me with that one as well napoleon, its worse than stationary engineman....:D :D

napoleon
08-12-2005, 10:24 PM
Hello slingblade! Francophones is a combination of two words in one. Franco is latin for French. Phones is greek
for Voices (literally). Therefore, a Francophone signifies, in literal terms, Frenchvoice. It is anyone who speaks french as a 1st language. Anglophone signifies that an individual speaks english as a first language. I can see how the latin/greek roots can be confusing. Hope this clarifies the meaning.

DavidHang
28-12-2005, 04:51 AM
for Q1

I think the correct key is b c d, because the a b c are all high side in refrigeration system.

Abe
28-12-2005, 10:57 AM
David

I think youve had too much rice wine

Did you just wake up from your stupor??

:D :D :D

psss........Ignore me, just my New Years humour kicking in

Question was asked like two months ago !!

mccoolair@yahoo
17-01-2006, 12:11 AM
I took a company HVAC test for a service tech position. There were two questions to be answered by referring to a schematic at the bottom of the page, A ladder diagram of a low volt circuit. The question was ,"If there was a short in the circuit, what components would not work as a result? It referrenced a point Y on the power side of a 24 volt transformer, and point B on the other side of the "fan on" switch. Now, I am only aware of two kinds of shorts; A short-to-ground, and a turn-to-turn short in a motor's windings. I answered that nothing would work because a short in the low voltage circuit (short-to-ground) would burn out the transformer, since there was no fuse protecting the transformer in the diagram. The test proctor could not explain what type of short it was referring to. Did I miss that one?

dogma
25-01-2006, 09:37 AM
active - neutral short ???????????????????????????????????????????????????????????????????????????????????????????????????? ??