Term
| True or False: Low pressure chillers can be leak tested by heating them until they reach 30 PSIG. |
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Definition
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Term
| True or False: Continuous cycling or pulsing of the purge could be a sign of a leak. |
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Definition
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Term
| True or False: At atmospheric pressure, R-11 is about 120 degrees F. |
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Definition
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Term
| The burst pressure for a rupture disc on a low pressure chiller is 15 PSIG. |
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Definition
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Term
| HCFC 123 would be considered a _ class refrigerant. |
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Definition
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Term
| A centrifugal chiller purge compressor takes its suction from the... |
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Definition
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Term
| The rupture disk of a low pressure centrifugal chiller is connected to its... |
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Definition
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Term
| Refrigerant rupture disks or frangible disks should be piped to the |
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Definition
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Term
| The purge unit of a low pressure centrifugal water chiller... |
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Definition
| removes a sample from the top of the condenser. |
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Term
| The purge unit of a low pressure centrifugal returns most of its captured refrigerant to the... |
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Definition
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Term
| Systems that contain a low pressure refrigerant such as CFC-11 are required to be evacuated to what pressure with new recovery equipment before opened for service? |
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Definition
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Term
| True or False: The purpose of the purge unit on low pressure equipment is to purge the refrigerant vapor from the condenser to the atmosphere. |
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Definition
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Term
| The TLV-TWA (threshold limit value / time weighted average) of a mechanical room should be protected by a |
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Definition
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Term
| Which leak testing method should be used to properly pressurize a low pressure chiller which contains refrigerant? |
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Definition
| Circulate controlled warm water through the evaporator tubes. |
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Term
| After all the liquid is removed from a 350 ton chiller, there is probably still about _ lbs of refrigerant vapor to be recovered. |
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Definition
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Term
| Typical Refrigerants used of low pressure appliances (low pressure chillers) are... |
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Definition
| HCFC-123, CFC-11, HFC-245a, & HFO-1233zd |
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Term
| In vapor compression systems containing CFC's or HCFC's acid formation can be caused by... |
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Definition
High condensing temperatures;
moisture in the refrigerant;
high compression ratios;
non condensibles |
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Term
| A water source recovery unit would probably use _ for a condenser cooling medium. |
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Definition
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Term
| A "high efficiency" purge unit is an indication that the percentage of _ separated and sent to the _ is much less than a conventional unit. |
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Definition
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Term
| Low pressure chiller tubes might be "individually" tested with a... |
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Definition
| hydrostatic tube test kit |
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Term
| Recovering refrigerant from a chiller with "leaking tubes" might be a good reason to... |
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Definition
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Term
| To reduce the leak rate on an idle low pressure chiller we would |
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Definition
| maintain near atmospheric pressure |
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Term
| Flooded chillers would not use _ as a refrigerant. |
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Definition
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Term
| Recovery of a chiller should usually include running the _ or _ during refrigerant recovery. |
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Definition
| chilled water pump; condenser water pump |
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Term
| Removing frost at sightglasses on low temperature systems may best be achieved by spraying the sight-glass with... |
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Definition
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Term
| When moisture is present in the system, an extra large vacuum pump could easily cause _ if the depth of the vacuum levels are not carefully controlled. |
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Definition
| any moisture in the system to freeze |
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Term
| When recovering refrigerant from large systems, the quickest method is to remove _ refrigerant from the system. |
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Definition
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Term
| Industrial process refrigeration systems with leakage rates above _ per year require leak repair. |
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Definition
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Term
| Commercial refrigeration systems with leakage rates above _ per year require leak repair. |
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Definition
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Term
| Typical Commercial Air conditioning systems with leakage rates above _% of the charge per year require leak repair if the total system charge is _ lbs. |
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Definition
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Term
| The process of removal and return of a refrigerant to a system is known as... |
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Definition
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Term
| Non-condensables will collect at the _ of the system. |
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Definition
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Term
| The industrial standard unit for deep evacuation is... |
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Definition
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Term
| After recovery of a refrigerant from a system to the required evacuation level, the next step would be to... |
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Definition
| wait and observe pressure levels |
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Term
| While servicing either chillers, systems with water cooled condensers or systems with water cooled heat exchangers of any type, be careful to avoid freezing of the tubes or heat exchanger while... |
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Definition
| recovering refrigerant; charging the system from a deep vacuum. |
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Term
| The lowest point on the chiller is usually _ where refrigerant is recovered or added. |
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Definition
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Term
| During a low pressure chiller oil change, it would be best to remove the oil from the chiller at _ so the minimum amount of refrigerant is removed/released. |
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Definition
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Term
| While there are exceptions to the rule, leak repairs are to be completed within... |
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Definition
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Term
| Leak rates exceeding _% of the nameplate charge per year require reporting to the EPA. |
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Definition
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Term
| HCFC-123 at STP would have a boiling point closest to... |
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Definition
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Term
| Low pressure refrigerants are identified as having a liquid saturation pressure of no greater than _ PSIG at a temperature of _ degrees F. |
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Definition
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Term
| _ leak checks for a period of _ are required after a commercial refrigeration or industrial process system have leaked beyond the standard allowed annual rate. |
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Definition
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Term
| ASHRAE recommends that a low pressure chiller should initially be evacuated to _ and final evacuation shal be to _. |
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Definition
| 1 MM Hg and not leak beyond 2.5 MM Hg, 500 microns |
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