South Carolina - Packaged Equipment
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What's on the exam
Questions per topic, out of 80Topics
General Piping
Key Concepts
Gas piping pressure testing (SC Fuel Gas Code 2021, Chapter 4) - 406.4.1 Test Pressure: the test pressure shall be not less than 1½ times the proposed maximum working pressure, but not less than 3 psig (20 kPa gauge), irrespective of design pressure. Where the test pressure exceeds 125 psig, the test pressure shall not exceed a value producing a hoop stress greater than 50 percent of the specified minimum yield strength of the pipe. - 406.4 Test Pressure Measurement: measured with a manometer or a calibrated pressure-measuring device; the pressure source shall be isolated before testing. Mechanical gauges shall have a range such that the **highest end of the scale is not greater than five times…
General Tubing
Key Concepts
Tubing identification and sizing - ACR (air-conditioning and refrigeration) tubing is designated by its actual outside diameter; most other tubing is designated by the inside diameter (Modern Refrigeration and Air Conditioning, 22nd ed., Ch. 5, Sec. 5.1, Figures 5-1 and 5-3). - Copper water tubing nominal size = outside diameter minus 1/8″ (Sec. 5.1.1). - Copper tubing comes in wall thicknesses Type K (heavy wall) and Type L (medium wall); Type L is the commonly used type (Sec. 5.1.1). - Soft ACR tubing is hard-drawn copper that has been annealed; it is sold in 25′, 50′, and 100′ rolls, in sizes most commonly 3/16″ to 3/4″ OD (Sec. 5.1.1). - Hard-drawn Type L or K ACR tubing…
Pipe Assembly
Key Concepts
Valves (Pipefitter's Handbook, 3rd ed., Chapter 1) - Angle valves have the same basic characteristics as globe valves. Used to make a 90-degree turn in a line, an angle valve gives less restriction to flow than the elbow-and-globe-valve combination it displaces (Ch. 1, Angle Valves). - Gate valve bonnets may be bolted to the body or constructed as a yoke, exposing the stem or spindle (Ch. 1, Gate Valves — Description).
Bends and changes in direction (SC Fuel Gas Code 2021, Section 405, IFGS) - 405.1: changes in direction may be made by fittings, factory bends or field bends. - 405.2, metallic pipe: bends made only with bending tools and procedures intended for the purpose; smooth and…
Piping Systems
Key Concepts
Valve selection, parts and troubleshooting (Pipefitter's Handbook, Ch. 1) - Pair swing check valves with gate valves, and lift checks with globe and angle valves. Flow through a swing check is straight-way like a gate valve; the lift check requires a change in direction of flow, as in a globe valve (Check Valves — Service Characteristics). - In a gate valve, the packing gland bushing, or follower, installed between the gland or nut and the packing, transmits the force exerted by the packing gland or nut to the packing (Gate Valves — Description). - Globe valve stem leakage remedies: bent or scored stem → replace the stem; loose packing gland or nut → tighten it; worn-out packing…
Drain Piping
Key Concepts
Buried drain lines (Pipefitter's Handbook, 3rd ed., Page 3-25 — Buried Lines). The trench bottom is prepared with 4 to 6 inches of fill beneath the pipe that is free of rocks and other sharp objects. The same type of rock-free fill is recommended for the first 8 to 12 inches of backfill, so that the material fully encloses the line; normal backfill follows. All buried lines are laid below frost level, and cemented (solvent welded) joints are recommended for buried runs. Note that these are two different figures for two different stages — bedding below the pipe versus initial backfill over and around it.
Valves
Key Concepts
Metering devices as valves — TXV operation and adjustment - A TXV adjusts refrigerant flow using a sensing bulb on the evaporator outlet. If bulb pressure is greater than low-side (evaporator) pressure, the valve is forced open; if low-side pressure is greater, the valve closes (Ch. 45.1). - Turning the adjustor clockwise increases spring pressure; counterclockwise reduces it. Increased spring pressure requires a larger pressure difference to open the valve, admits less refrigerant, and raises superheat — carried too far this is starving the evaporator. Decreased spring pressure lowers superheat; carried too far, refrigerant leaves the evaporator unevaporated (flooding), which can cause liquid slugging at the compressor (Ch. 45.1.1). - Some TXV adjusting screws "should not be…
Piping Insulation
Key Concepts
Insulation characteristics and fire ratings (SCMC 2021 Section 1204.1). Pipe insulation installed in buildings shall conform to the International Energy Conservation Code; shall be tested in accordance with ASTM E84 or UL 723, using the specimen preparation and mounting procedures of ASTM E2231; and shall have a maximum flame spread index of 25 and a smoke-developed index not exceeding 450. Insulation installed in an air plenum shall comply with Section 602.2.1. Exception: the maximum flame spread index and smoke-developed index shall not apply to one- and two-family dwellings.
Required thickness (Section 1204.2). Hydronic piping shall be insulated to the thickness required by the International Energy Conservation Code. The code itself gives no inch value.
Hangers and Supports (General)
Exam: South Carolina – Packaged Equipment
Key Concepts
Steel pipe support-spacing tables (water, gas, steam service). The published spacing tables for standard weight steel piping are based on average conditions. The footnotes state the tabulated spacing "does not include allowance for flanges, fittings and valves, but does include allowance for insulation." Because flange, fitting and valve loads are not covered by the table, heavy fittings such as valves should always be located close to a support. (Pipefitter's Handbook, 3rd ed., Pages 2-67 to 2-68)
Mechanical Sound, Vibration, and Seismic Control
South Carolina – Packaged Equipment
Key Concepts
Noise sources (ACCA Manual D, 3rd ed., Appendix 13, pp. 185–186) - Noise is produced by the blower and can be generated by air-side components, dampers, fittings, supply outlets and return grilles. Noise is generated when airflow velocities are too high. Noise is produced by equipment vibrations (A13 intro, p. 185). - Blower noise propagates downstream through the supply duct and upstream, against the flow, in the return duct, and can also be transmitted through the equipment cabinet and/or duct walls (A13-1, p. 185). - Duct-run noise comes from turbulence caused by inefficient fittings (elbows, tees, transitions, takeoffs) and sternly throttled dampers (A13-2, p. 185). - Air distribution component noise intensity depends…
Heating and Cooling Principles
Key Concepts
Design temperatures. The Manual J "bulls eye" for heating is 70°F dry-bulb; for cooling it is 75°F dry-bulb and 50% RH in a wet-coil climate (75°F and 45% RH for a dry-coil climate) (Manual J, Section 3, Page 3-6; Figure 3-1). Outdoor design conditions come from Table 1 values used exactly as published (Figure 3-1).
Choosing the outdoor design value. The 99.6% value is used for residences and small, poorly insulated office buildings; the 99% value for well-constructed, well-insulated buildings with a standard number of windows; the 97.5% value for large buildings with considerable thermal capacity and small total window area. The record low is never used, because such extremes are of short duration (MRAC 20th ed.,…
Refrigerants
Key Concepts
Recovery equipment limits (EPA Section 608). System-dependent ("passive") recovery equipment may not be used on any appliance containing more than 15 lb of refrigerant (Modern Refrigeration and Air Conditioning, 20th ed., Appendix G — Type II, Recovery Requirements, p. 1570). Separate charge thresholds exist for other rules: 5 lb defines a small appliance, 50 lb is the charge threshold for leak-repair requirements, and 200 lb is the charge threshold that changes required evacuation vacuum levels (same citation).
Type I recovery percentages. Recovery equipment must remove 90% of the refrigerant when the compressor is operating, but only 80% when the compressor is not operating (Appendix G — Recovery Procedures, Type I Certification, p. 1572). These are two separate…
Load Calculations
Key Concepts
- Heating loads are deliberately conservative. The heating estimate ignores solar gain, thermal mass effects, and internal loads (occupants, appliances, lighting) — a simplification that provides a built-in safety factor (Manual J, Section 4-1).
- No additional safety factor at sizing. The total heating load shall be used for equipment sizing exactly as it appears on the form, with no "safety factor" adjustment; manufacturer's performance data is then used to select equipment (Manual J, Section 4-12).
- Design temperature differences. HTD = (Indoor − Outdoor)design; CTD = (Outdoor − Indoor)design (Manual J, Section 18-4; Manual N, Sections 4-4/4-5). Partition TD: PTDH = (Indoor − Unconditioned space temp) (Manual N, Section 4-9).
- Outdoor design values. Manual J/N…
Heating and Cooling Equipment
Key Concepts
Hydronic boilers and mixing valves - A conventional (noncondensing) boiler operates at water temperatures above 140°F (60°C) so combustion gases do not condense; if water drops below 140°F (60°C), the condensing combustion gases become highly corrosive and damage the boiler and flue. Boilers generally operate from 90°F to 200°F (32°C to 93°C) (22nd ed., Ch. 38, Section 38.1.1). - A mixing valve blends hot supply water with cooler water. It may be installed at the boiler inlet (monitoring return water) or boiler outlet (monitoring supply water). Common settings: 140°F (60°C) for return water installations and 160°F (71°C) for supply water installations (Section 39.1.4 — Mixing Valves, Page 1042). - In a supply water installation, if water leaving…
Testing, Adjusting, and Balancing (TAB)
South Carolina – Packaged Equipment · 2 questions (2% of exam)
Key Concepts
Airflow measurement instruments - An air handler flowmeter is placed in the air stream of an air handler to measure the total airflow of a central system, and is typically sized to fit over a large return grille or in the space normally occupied by the system's air filter (Modern Refrigeration and Air Conditioning, Sec. 30.1.3, p. 789). - A flow hood directs and calculates all of the airflow through a duct at a given (individual) supply or return (Sec. 31.1.2). A duct blaster pressure tests ductwork for leakage (Sec. 30.1.3 explanation, p. 789). - Other useful airflow instruments: manometer, barometer, pitot tube, anemometer, smoke (as…
HVACR Control Fundamentals
Key Concepts
Range vs. differential (Section 16.2.1–16.2.2, Pages 354–357) - Differential = the difference between cut-out and cut-in. For a cooling system: cut-in – cut-out = differential. For a heating system: cut-out – cut-in = differential. Always subtract the lower value from the higher. - Range adjustment moves cut-in and cut-out equally in the same direction: the average set point changes, the differential does not. - Differential adjustment changes the spread. Three control types: cut-in control (cut-in only), cut-out control (cut-out only), combination control (both). - Governing principle: increasing the differential lengthens run time and lengthens the interval between cycles; decreasing the differential shortens run time and shortens the interval (Pages 356–357). - Pro Tip: "Whenever the differential is…
Control Schematics and Wiring Diagrams
Key Concepts
Ladder vs. pictorial diagrams. A ladder diagram is drawn as two vertical power lines with numbered horizontal rungs between them, each rung containing a load and its controls. The diagram is set up to reflect the order of component operation — devices nearer the top are energized before devices further down — which makes it the preferred diagram for troubleshooting sequence-of-operation problems. Physical location of components and wire colors are shown on a pictorial diagram, not a ladder diagram. (Modern Refrigeration and Air Conditioning, 20th ed., Page 352; "ladder diagram" and "pictorial diagram" are the two basic diagram types in Ch. 18, Section 18.2-1, Page 381.)
HVACR Control Systems
Key Concepts
Multistage thermostats. Thermostats with a W2 or Y2 terminal are multistage thermostats. In heating mode, the thermostat "will not close across terminals R and W2 until the temperature drops down below the set point by more than 3°F, in most cases." In cooling mode, "terminals R and Y2 will not close until the temperature rises above the set point by more than 3°F." These first-to-second-stage separations "are adjustable in many cases," so when troubleshooting a second-stage complaint you must adjust the thermostat far enough to close the correct terminals. (20th ed., Page 966 — Section 36.8.3 Multistage HVAC Systems)
Machine Room
Key Concepts
- When a machinery room is required (Section 1104.2). All refrigerant-containing components must be located outdoors or in a machinery room where the quantity of refrigerant in an independent circuit exceeds the amounts in Table 1103.1. For blends not listed, the requirement applies where any blend component exceeds its Table 1103.1 amount, or where the combined amount of blend components exceeds 69,100 ppm by volume. Rooms are built per Section 1105 for Group A1 and B1 refrigerants, and per Sections 1105 and 1106 for Groups A2, B2, A3 and B3.
- Exception 1 to 1104.2: machinery rooms are not required for listed equipment and appliances containing not more than 6.6 pounds (3 kg) of refrigerant, **regardless of…
Air Conditioning Systems
Key Concepts
Equipment types and capacities - Rotary compressors power small refrigerated appliances — window air conditioners, packaged terminal air conditioners, and heat pumps up to five tons — and have high volumetric efficiency (20th ed., Ch. 18, Sec. 18.2.2). - A console air conditioner (stand-up cabinet, also called a vertical PTAC) houses the condensing unit in one section and the blower and evaporator in another, and varies in capacity from 1/2 ton to 4 tons (22nd ed., Sec. 22.4, p. 469). - VRF systems: one outdoor unit serves a large number of indoor units, each with its own thermostat setting, connected by a trunk and branch piping system rather than the individual line sets used in mini-splits (22nd…
Heat Pumps
Key Concepts
Basic operation and flow direction - In heating mode the outdoor coil acts as the evaporator (absorbing heat) and the indoor coil acts as the condenser; in cooling mode the reversing valve shifts and the functions swap (Ch. 36, Section 36.1, 22nd ed., pages 877–878). - Although refrigerant direction through the coils reverses, refrigerant flow through the compressor is always in the same direction (Section 36.1, page 878). - Neither coil is permanently an "evaporator" or "condenser" — they are the indoor coil and outdoor coil (Pro Tip, Section 36.1, page 877). - In a split heat pump, the larger line is called the gas line (always carries gas) and the smaller is the liquid line (always…
Furnaces (Warm Air Heating Equipment)
Key Concepts
Combustion fundamentals - Combustion is a chemical process of rapid oxidation in which fuel and oxygen produce heat and light. The three basic elements necessary are fuel, heat, and oxygen (Section 41.2, Figure 41-2). - Stoichiometric (perfect) combustion formula: CH₄ + 2 O₂ = CO₂ + 2 H₂O + energy — oxygen-to-fuel ratio of 2:1 (Section 41.2). - Gas furnaces cannot achieve stoichiometric combustion but can achieve complete combustion, in which fuel burns in the presence of excess oxygen to produce water and carbon dioxide (Section 41.2). - Combustion fuels most commonly used for heating: natural gas, liquefied petroleum (LP) gas, and fuel oil (Section 41.2).
Chimneys, Flues, Vents, and Vent Connectors
Key Concepts
Venting categories (Modern Refrigeration & A/C, 20th ed., Section 41.8, Fig. 41-30, p. 1134) - Category I — negative vent pressure, noncondensing → Class B vent. - Category II — negative vent pressure, condensing (flue gas below dew point, condensate forms) → special vent material specified by the manufacturer. - Category III — positive vent pressure, noncondensing (flue gas stays above dew point) → stainless steel piping. - Category IV — positive vent pressure, condensing → PVC. - Gas furnaces rated over 83% AFUE develop condensation in the heat exchanger or flue vent; at or below 83% they do not. 78% AFUE is the federal minimum for new furnaces; 79%–83% is the mid-efficiency range (Section 41.7, pp.…
Combustion Air
SC Packaged Equipment
Key Concepts
- Which code applies. Combustion and dilution air for gas-fired appliances is governed by Section 304 of the SC Fuel Gas Code; appliances burning fuels other than fuel gas are regulated by the SC Mechanical Code (IFGC 301.1.1). In the SCMC, solid fuel-burning appliances get combustion air per the manufacturer's installation instructions and oil-fired appliances per NFPA 31; those methods do not apply to fireplaces, fireplace stoves and direct-vent appliances (SCMC 701.1).
- Permitted methods. Air shall be provided by one of the methods in Sections 304.5 through 304.9. Where Section 304.5 is not met, outdoor air shall be introduced per 304.6 through 304.9. Direct-vent appliances, gas appliances of other than natural draft design,…
General Fuel Knowledge
South Carolina – Packaged Equipment (1 question, ~1% of exam)
Key Concepts
Combustion definitions (SC Fuel Gas Code 2021, Chapter 2, Section 202) - Combustion: "the rapid oxidation of fuel accompanied by the production of heat or heat and light." - Combustion air: "Air necessary for complete combustion of a fuel, including theoretical air and excess air." - Combustion products: "Constituents resulting from the combustion of a fuel with the oxygen of the air, including inert gases, but excluding excess air." - Btu: the quantity of heat required to raise the temperature of 1 pound (454 g) of water 1°F (0.56°C); 1 Btu = 1055 J.
Natural Gas
Key Concepts
Scope and pressure limits - The code covers piping systems for natural gas with an operating pressure of 125 psig (862 kPa gauge) or less, and for LP-gas with an operating pressure of 20 psig (140 kPa gauge) or less, except as provided in Section 402.7. Coverage extends from the point of delivery to the outlet of the appliance shutoff valves (SC Fuel Gas Code 2021, § 101.2.2). - Plastic pipe shall not be operated at pressures greater than 100 psig for natural gas or 30 psig for LP-gas (IFGC § 404.17.1; SC Fuel Gas Code 2021, Chapter 4). - Chapter 4 applies to piping from the point of delivery to the connections with the appliances, including…
General Duct Systems Knowledge and Principles
South Carolina – Packaged Equipment | 4 questions (5% of exam)
Key Concepts
Available static pressure and friction rate. Duct sizes are based not on the blower's external static pressure but on the net pressure left after component losses: "the pressure dissipated by one or more items must be subtracted from the external static pressure value from the OEM's blower table" (Manual D, Section 1-11). ASP = ESP – component/device pressure losses (Friction Rate Worksheet Steps 1–3; Manual D Section 6-5). The friction rate converts that pressure drop to the 100-ft reference distance used by friction charts and duct slide rules (Manual D, Section 1-6; MRAC 22nd ed. Section 30.5.2, p. 687).
Duct Conversion/Equivalencies
South Carolina – Packaged Equipment | 4 questions (5% of exam)
Key Concepts
- Equal-friction basis. Chart 9, Circular Equivalents of Rectangular Ducts, and Chart 10, Circular Equivalents of Oval Ducts, are both titled "Based on Equal Friction Rate" (Appendix 2, Pages 103–105). Section 6-20 confirms the equivalent rectangular size "produces the same airflow resistance (friction rate) as the round size, but the velocity through the equivalent rectangular airway is always lower than the velocity through the round airway."
- Equivalent sizes vary by tool. Section 6-20: equivalent rectangular sizes "may vary, depending on the duct slide rule, because the industry has two, slightly different, equations."
- Hydraulic diameter. Section A1-13: "For a given material, duct shapes that have…
Mechanical Sheet Metal Devices/Systems
Key Concepts
Room air movement. Air delivered into a room from a supply outlet is primary air. Throw is the distance air travels from the duct outlet before it slows to 50 fpm (Modern Refrigeration and Air Conditioning, Section 29.2.1, p. 748). The 500 fpm figure is the register velocity above which occupants feel a draft — not the throw reference velocity.
Transitions. When reducing a round or rectangular duct, the taper is approximately 1″ of size reduction for every 4″ of length. When a duct is enlarged, the dimension is increased 1″ for every 4″ to 7″ of length (Section 29.4.4, p. 763).
Duct System Components
Key Concepts
Duct types and layout. The supply air system may be a trunk and branch system, a radial system, a perimeter loop system, or a plenum system (Manual D, Section 5-1). One design friction rate, based on the largest effective length value, is used to size all trunk ducts and all branch runs (Manual D, Section 1-9). Where a trunk is reduced, the taper is approximately 1″ for every 4″ of length; when enlarged, dimensions increase 1″ for every 4″ to 7″ of length (Modern Refrigeration and AC 20th ed., Section 29.4.4, p. 763). A branch takeoff centerline shall be at least 18 inches upstream from a trunk end plate or trunk reducing fitting (Manual D, Section 5-6).…
Metal Ducts
Key Concepts
Duct sizing by friction rate (the core calculation). Duct sizes are based not on the blower's external static pressure but on the net pressure available after component losses: ASP = ESP – DPL (CPL) (Modern Refrigeration and Air Conditioning, 20th ed., pp. 770–772; ACCA Manual D, Section 1-11 and Friction Rate Worksheet, Steps 1–3). Manual D's procedure runs in order: Effective Length Worksheet → TEL, Friction Rate Worksheet → ASP, then FR, then Duct Sizing Worksheet for Cfm, airway size, and velocity check (Manual D, Section N1-4, Figure N1-1).
Fiberglass Ducts
Key Concepts
Material and listing (SC Mechanical Code 2021, Section 603.5 — Nonmetallic Ducts). Nonmetallic ducts shall be constructed with Class 0 or Class 1 duct material and shall comply with UL 181. Fibrous duct construction shall conform to the SMACNA Fibrous Glass Duct Construction Standards or NAIMA Fibrous Glass Duct Construction Standards. The air temperature within nonmetallic ducts shall not exceed 250°F (121°C) — a maximum, not a setpoint.
Related temperature limits that are not the fibrous glass limit. Gypsum board air shafts: return air systems only, air temperatures not exceeding 125°F (52°C), with the board surface held above the airstream dew point (Section 603.5.1). Underground plastic (PVC) duct and fittings: maximum design temperature 150°F (66°C) (Section 603.8.3).…
Filtering Systems
South Carolina – Packaged Equipment | 1 question (≈1% of exam)
Key Concepts
Indoor air quality defined. Indoor air quality (IAQ) includes the status of indoor air as measured by temperature, humidity, fresh airflow, pollutants, and chemicals in an enclosed space. A good air-conditioning system delivers clean air to the conditioned space; air quality control includes more than just removal of contaminants. (22nd ed., Ch. 29 Air Quality, Introduction, p. 659)
Ozone from electronic air cleaners. Electronic air cleaners can slightly increase the ozone content of circulated air. For continuous occupancy, ozone should not exceed 0.01 ppm. Separately, 0.1 ppm is the maximum level generally considered permissible for an eight-hour exposure. These are two different limits for two different…
Ventilation Equipment and Devices
Key Concepts
Ventilation load basics (Manual N). The sensible ventilation load is found with the sensible heat equation; the altitude correction factor (ACF) comes from Table 10A (Manual N Section 10-3, p. 88). Latent load uses the latent heat equation with the grains difference (Section 10-4, p. 88). Indoor defaults are 70°F for heating and 75°F for cooling (Section 10-13/Worksheet H, p. 91).
Design ventilation rate — three candidate values. For comfort systems there are potentially three values for outdoor air CFM, and the largest of the three is used to calculate the ventilation load: outdoor CFM for occupants, outdoor CFM for make-up air, and leakage through a closed outdoor air damper (Manual N Section 10-11, p. 90).
Exhaust Systems
Key Concepts
Exhaust discharge location (Section 501.3.1). Termination points must meet these minimums: - Ducts conveying explosive or flammable vapors, fumes or dusts (Item 1): 30 ft from property lines; 10 ft from operable openings into buildings; 6 ft from exterior walls and roofs; 30 ft from combustible walls and operable openings in the direction of exhaust discharge; 10 ft above adjoining grade. - Other product-conveying outlets (Item 2): 10 ft from property lines; 3 ft from exterior walls and roofs; 10 ft from operable openings; 10 ft above adjoining grade. - Environmental air exhaust (Item 3): 3 ft from property lines; 3 ft from operable openings (other than Group U); 10 ft from mechanical air intakes.
General Electrical Knowledge
South Carolina – Packaged Equipment | 2 questions (2% of exam)
Key Concepts
OSHA 1926 Subpart K — organization. Installation safety requirements are in §§1926.402–1926.408; safety-related work practices in §§1926.416 and 1926.417; maintenance and environmental considerations in §§1926.431 and 1926.432; special equipment in §1926.441; definitions in §1926.449 (§1926.400).
Assured equipment grounding conductor program. When used in place of GFCI protection, cord sets must be tested before first use, before return to service after repairs, after any incident suspected of causing damage, and at intervals not to exceed 3 months. The 6-month interval applies only to cord sets and receptacles that are fixed and not exposed to damage (§1926.404(b)(1)(iii)(E)).
Requirements for Electrical Installations
Key Concepts
Scope and applicability. §§1926.402 through 1926.408 contain installation safety requirements for electrical equipment and installations used to provide electric power and light at the jobsite, and apply to installations both temporary and permanent, but not to existing permanent installations in place before construction began (§1926.402(a)). The subpart does not cover generation, transmission and distribution installations, but it does cover portable and vehicle-mounted generators used to power equipment at the jobsite (§1926.402(b)). Installation made per the National Electrical Code ANSI/NFPA 70–1984 is deemed in compliance with §§1926.403–1926.408 except §1926.404(b)(1) and §1926.405(a)(2)(ii)(E), (F), (G) and (J) (Note to §1926.402).
Electrical/Electronic Fundamentals
Key Concepts
Identifying unmarked compressor terminals. On a single-phase hermetic compressor, the highest resistance reading between any pair of terminals is between the start (S) and run (R) terminals, because that measurement passes through both windings in series. The terminal not included in that highest reading is the common (C) terminal. (Modern Refrigeration and Air Conditioning, 20th ed., Section 15.5.1, Identifying Unmarked Compressor Terminals)
Class 2 control circuits. A Class 2 circuit is supplied by a power source with an output no greater than 30 V and 1000 VA, and consists of the portion of the wiring between the power source and the connected equipment. Thermostat and remote-control circuits for HVACR equipment are typical Class 2 circuits, and HVACR…
Safety
Key Concepts
Fire protection and extinguishers (Subpart F, §1926.150) - The employer is responsible for developing a fire protection program for all phases of construction and demolition work, and must provide the firefighting equipment specified in the subpart (§1926.150(a)(1)). Access to all available firefighting equipment must be maintained at all times (a)(2), equipment must be conspicuously located (a)(3), and must be periodically inspected and maintained in operating condition, with defective equipment immediately replaced (a)(4). - A fire extinguisher rated not less than 2A shall be provided for each 3,000 square feet of the protected building area, or major fraction thereof. Travel distance from any point of the protected area to the nearest extinguisher shall not exceed 100 feet (§1926.150(c)(1)(i)).…
Fire Rated Construction
Exam: South Carolina – Packaged Equipment
Key Concepts
Temporary buildings (OSHA 29 CFR 1926, Subpart F) - §1926.151(b)(2): Temporary buildings located within another building or structure shall be of either noncombustible construction or of combustible construction having a fire resistance of not less than 1 hour. - §1926.151(b)(1): No temporary building shall be erected where it will adversely affect any means of exit.
Fire doors and stored material - §1926.151(d)(7): A clearance of 24 inches shall be maintained around the path of travel of fire doors unless a barricade is provided, in which case no clearance is needed. Material may not be stored within 36 inches of a fire door opening.
General Plan Reading
South Carolina – Packaged Equipment · 1 question (1% of exam)
Key Concepts
Where survey information comes from. For proposed construction, survey information is obtained from drawings and specifications and from conversations with the builder, architect or owner. For existing construction, it comes from drawings and specifications (when available), on-site inspection, and talking with the builder or owner. Verify conformance to the plan when working from plans for existing construction; investigate possible changes and modifications when working with plans for proposed construction. (Manual J, Appendix 5 — Survey)