313D Regulations, Codes, and Safety Standards 3 — Questions and Answers
Question 1: Which regulation governs the transportation of refrigerant cylinders by road and specifies proper labeling and packaging requirements?
- EPA 40 CFR Part 82
- DOT 49 CFR Part 173 (Correct answer)
- OSHA 29 CFR 1910.101
- NFPA 55
Correct answer: DOT 49 CFR Part 173
DOT 49 CFR Part 173 establishes packaging, labeling, and hazmat shipping requirements for compressed gas cylinders including refrigerants transported by road.
Question 2: What is the purpose of a high-pressure relief device required by ASHRAE 15 on refrigerant systems?
- To vent refrigerant when the system is decommissioned
- To prevent system pressure from exceeding the design working pressure (Correct answer)
- To balance pressure between the high and low sides
- To protect the compressor from liquid slugging
Correct answer: To prevent system pressure from exceeding the design working pressure
ASHRAE 15 mandates pressure relief devices to automatically vent refrigerant and prevent catastrophic failure if system pressure exceeds the maximum allowable working pressure.
Question 3: Under the 2021 International Residential Code, what is the minimum required capacity for a condensate overflow shutoff device?
- The device must stop the unit before the overflow pan fills (Correct answer)
- There is no capacity requirement, only a location requirement
- It must handle twice the rated condensate flow
- It must activate within 60 seconds of overflow detection
Correct answer: The device must stop the unit before the overflow pan fills
The IRC requires overflow shutoff devices to stop unit operation before condensate overflows the secondary pan, preventing water damage regardless of specific flow capacity.
Question 4: Which safety standard specifically addresses electrical requirements for motor-compressors and their associated control equipment in air conditioning systems?
- NEC Article 430
- NEC Article 440 (Correct answer)
- UL 1995
- NFPA 70B
Correct answer: NEC Article 440
NEC Article 440 specifically covers hermetic refrigerant motor-compressor electrical requirements, including conductor sizing, overcurrent protection, and disconnect means.
Question 5: When is a mechanical room required by ASHRAE 15 for a residential refrigeration system using a Group A1 refrigerant like R-410A?
- Always, regardless of charge size
- Never; Group A1 refrigerants are exempt from mechanical room requirements (Correct answer)
- When the system charge exceeds the room quantity limit (RQL)
- Only when the system is installed in a basement
Correct answer: Never; Group A1 refrigerants are exempt from mechanical room requirements
ASHRAE 15 exempts Group A1 refrigerants (low toxicity, nonflammable) from mandatory mechanical room requirements because they pose minimal risk in occupied spaces.
Question 6: According to NFPA 70 (NEC), what disconnecting means is required within sight of a residential central air conditioning unit located outdoors?
- A 15-amp fused disconnect
- A readily accessible, lockable disconnect (Correct answer)
- A GFCI-protected receptacle
- A manual motor starter
Correct answer: A readily accessible, lockable disconnect
NEC Article 440 requires a disconnect that is within sight of the equipment, readily accessible, and capable of being locked in the open position to allow safe servicing.
Question 7: What is the primary purpose of the UL 207 standard as it relates to residential air conditioning systems?
- It certifies refrigerant reclamation equipment
- It covers refrigerant-containing components such as filter driers and liquid indicators (Correct answer)
- It establishes technician certification requirements
- It defines refrigerant safety group classifications
Correct answer: It covers refrigerant-containing components such as filter driers and liquid indicators
UL 207 (Refrigerant-Containing Components and Accessories) covers pressure-containing components like filter driers, sight glasses, and liquid line components used in refrigerant systems.
313D Regulations, Codes, and Safety Standards 3
Which regulation governs the transportation of refrigerant cylinders by road and specifies proper labeling and packaging requirements?