Nevada A-10B Residential Spas Contractor Examination

What does spa turnover time measure?

• AThe time needed to circulate a volume of water equal to the spa capacity through the filt…
• BThe time needed to raise spa water 10°F
• CThe time a bather may legally remain in water at 104°F
• DThe time between required spa drain-and-refill cycles

Under USPSHTC 2018 water-quality practice and ANSI/APSP residential spa standards, what maximum turnover time is used to size a residential spa circulation system?

• A30 minutes
• B15 minutes
• C2 hours
• D6 hours

A residential spa holds 600 gallons. What minimum circulation flow rate is required for a 30-minute turnover?

• A10 gpm
• B15 gpm
• C20 gpm
• D30 gpm

A rectangular residential spa is 8 feet long, 6 feet wide, and has an average water depth of 3.5 feet. Using 7.5 gallons per cubic foot, what is the water volume?

• A840 gallons
• B1,008 gallons
• C1,260 gallons
• D1,680 gallons

Which filter type uses a cake of fossilized diatomaceous earth on septa or grids to trap fine particles?

• AHigh-rate sand filter
• BCartridge filter
• CDiatomaceous earth (DE) filter
• DRapid-rate gravity sand filter

A spa circulation system is designed for 30 gpm. If a cartridge filter is rated at 0.375 gpm per square foot of media, what minimum filter area is required?

• A8 square feet
• B30 square feet
• C80 square feet
• D113 square feet

Why are spa suction lines usually sized larger than the return lines for the same design flow?

• ATo keep suction velocity lower, reducing cavitation, hair entrapment risk, and pump strain
• BTo raise suction velocity and improve skimming
• CBecause PVC pressure ratings are lower on the suction side
• DSo the heater will see a higher entering velocity

What is the primary job of a surface skimmer on a residential spa?

• ATo draw floating debris and a surface layer of water into the filter so oils and dirt are…
• BTo provide the only legal suction outlet under the Virginia Graeme Baker Act
• CTo equalize hydrostatic pressure under the spa shell
• DTo mix concentrated acid into the circulation stream

USPSHTC 2018 Section 511 requires spa suction outlet fitting assemblies to comply with which standard?

• AANSI/APSP/ICC-16 (SOFA) for listed suction outlet fitting assemblies
• BASTM F1346 only
• CNSF/ANSI 50 for residential filters only
• DACI 506 for shotcrete placement

On a two-pump residential spa, what is the correct split of duties between the circulation pump and the booster (jet) pump?

• AThe circulation pump provides filtration, heating, and disinfection flow at all times; th…
• BThe booster pump provides the required 30-minute filtration turnover; the circulation pum…
• CEither pump may be used for filtration as long as total horsepower exceeds 2 hp
• DBoth pumps must share one suction outlet cover

What is the maximum water temperature generally permitted for a spa or hot tub?

• A98°F (37°C)
• B100°F (38°C)
• C104°F (40°C)
• D110°F (43°C)

What pH range is maintained for spa water under USPSHTC Table 508.1 / APSP water-chemistry practice?

• A7.2 to 7.8
• B6.8 to 7.2
• C7.8 to 8.4
• D8.0 to 8.8

Compared with a swimming pool, why is the free-chlorine residual typically held higher in a residential spa (often about 3 to 5 ppm)?

• ABecause hot water, aeration from jets, and a high bather-to-water ratio consume sanitizer…
• BBecause spa heaters destroy chlorine below 2 ppm
• CBecause cyanuric acid cannot be used in any spa
• DBecause bromine is illegal in Nevada residential spas

What is the usual target range for total alkalinity in spa water?

• A80 to 120 ppm
• B20 to 40 ppm
• C200 to 400 ppm
• D1,000 to 1,500 ppm

What is the main purpose of shocking (superchlorinating or non-chlorine oxidizing) a residential spa?

• ATo oxidize bather waste and reduce combined chlorine so the water stays clear and odor-fr…
• BTo permanently raise calcium hardness
• CTo replace the need for a filter
• DTo lower the maximum heater set point

Why must a heavily used residential spa be drained and refilled on a regular cycle rather than only topping off evaporated water?

• ABecause total dissolved solids, combined organics, and sanitizer byproducts concentrate i…
• BBecause Nevada law forbids using the same fill water for more than seven days
• CBecause gunite shells must be kept dry to cure
• DBecause heaters cannot operate if the same water is recirculated

High calcium hardness combined with high pH and high temperature in a spa most often causes which problem?

• AScale on the shell, tile line, and heat exchanger
• BEtched plaster and corroded heater tubes
• CA sudden drop in total alkalinity to zero
• DLoss of all cyanuric acid

A spa test reads 4.0 ppm total chlorine and 1.5 ppm free chlorine. What is the combined chlorine, and what should the contractor tell the owner?

• ACombined chlorine is 2.5 ppm; oxidize (breakpoint/shock) and improve bather hygiene becau…
• BCombined chlorine is 5.5 ppm; add more stabilizer
• CCombined chlorine is 1.5 ppm; the spa is perfectly balanced
• DCombined chlorine cannot be calculated from those two readings

Why is bromine often chosen instead of chlorine for indoor residential spas?

• ABromine remains a more effective sanitizer than chlorine at the higher pH and temperature…
• BBromine is stabilized by cyanuric acid in sunlight
• CBromine does not require any oxidizer
• DBromine is exempt from USPSHTC water-chemistry limits

When a high-rate sand filter on a spa reaches the manufacturer's recommended pressure rise, what is the correct service action?

• ABackwash until the sight glass runs clear, then rinse and return to filter
• BAdd diatomaceous earth through the skimmer
• COpen the filter and acid-wash the sand every time pressure rises 1 psi
• DBypass the filter until the pressure falls on its own

A new residential spa is cloudy after start-up even though sanitizer and pH test in range. What is the most likely construction-related cause?

• APlaster dust, construction debris, or an undersized/dirty filter has not yet polished the…
• BThe hydrostatic relief valve is open
• CThe bonding grid is missing
• DThe ASTM F1346 cover is locked

A spa's Langelier Saturation Index is calculated at +0.7. What does that reading mean for operation?

• AThe water is scale-forming; lower pH, alkalinity, or calcium, or reduce temperature if pr…
• BThe water is balanced and no change is needed
• CThe water is corrosive; add calcium and raise pH
• DThe sanitizer residual is too low

How often should a residential spa owner test sanitizer and pH?

• AOnce per season
• BOnly when the water looks green
• CBefore each use, and more often during heavy bather loads
• DOnly after the annual drain-and-refill

When is cyanuric acid (stabilizer) appropriate in a residential spa?

• AIn every indoor bromine spa to protect bromine from UV
• BWhenever combined chlorine exceeds 1 ppm
• CIn outdoor chlorinated spas, kept in a moderate range (commonly about 30 to 50 ppm), beca…
• DAs a substitute for total alkalinity

Persistent foam on a residential spa is most often caused by which condition?

• ALow calcium hardness alone
• BA missing skimmer weir
• CBody oils, lotions, detergents, and high TDS in a small, agitated water volume
• DAn oversized sand filter

USPSHTC 2018 Chapter 7 requires a spa heater to be which of the following?

• AAny residential water heater rated 40,000 BTU or more
• BA boiler with an open expansion tank
• CSpecifically designed and listed for swimming pool, spa, or hot tub use and installed to…
• DAn unlisted heat exchanger cobbled from hydronic parts

A 500-gallon spa must be raised 30°F in 2 hours. Using BTU/hr = gallons × 8.33 × ΔT ÷ hours, what heater output is required (ignore losses)?

• A20,825 BTU/hr
• B41,650 BTU/hr
• C62,475 BTU/hr
• D124,950 BTU/hr

In a spa equipment train, where should a chemical feeder be installed relative to the heater?

• AOn the suction side of the pump
• BBetween the filter and the heater inlet
• CDownstream of the heater, with a check valve so treated water cannot backflow into the he…
• DIn the skimmer throat so chemicals mix before the pump

What electrical protection is required for permanently installed residential spa equipment circuits under NEC Article 680?

• AA standard thermal-magnetic breaker with no GFCI
• BOnly a lightning arrester on the gas valve
• CGFCI protection of the spa equipment circuit
• DA 15-amp fuse in the heater only

What conductor is typically required for the equipotential bonding grid of a permanently installed spa?

• A18 AWG stranded fixture wire
• B12 AWG aluminum NM-B
• C8 AWG solid copper
• D6 AWG steel rebar used as the only bonding jumper without copper connections

For a permanently installed spa in other than a one-family dwelling, NEC 680.41 requires a clearly labeled emergency shutoff to be located where?

• AInside the equipment enclosure, not visible to bathers
• BOn the opposite side of the property line
• CReadily accessible, within sight of the spa, and not less than 5 feet from the water
• DOnly at the utility transformer

What does an air blower (air inducer) do on a residential spa?

• AIt sanitizes the water with ozone
• BIt provides the 30-minute filtration turnover
• CIt injects air into the hydrotherapy fittings to increase agitation
• DIt vents the gas heater flue

A gas-fired spa heater must be installed with which of the following?

• AZero clearance to combustibles regardless of the listing
• BA water-heater-style temperature-and-pressure relief valve discharging into the spa
• CThe clearances, venting, combustion air, and gas piping required by the listing and the f…
• DThe chemical feeder mounted on the heater cabinet

A 600-gallon spa is heated by a 50,000 BTU/hr heater. Ignoring losses, how long will a 20°F temperature rise take? (Time = gallons × 8.33 × ΔT ÷ BTU/hr)

• A30 minutes
• B1 hour
• C2 hours
• D4 hours

Why should the hydrotherapy jets be capable of being shut off without stopping the filtration pump?

• ASo the spa can still turn over, heat, and sanitize when bathers are not using the jets
• BBecause jet pumps are not allowed to have strainers
• CBecause USPSHTC forbids two-speed motors
• DSo the air blower can provide the only circulation

Where should the pump vacuum gauge and the filter pressure gauge be installed?

• ABoth on the heater outlet
• BNeither is used on residential spas
• CBoth on the skimmer lid
• DVacuum gauge on the pump suction; pressure gauge on the filter (or filter influent) in th…

A listed spa heater specifies a minimum flow of 20 gpm and a maximum of 70 gpm. The jet booster can push 90 gpm through the heater loop. What is the correct installation response?

• AIgnore the listing because more flow always helps heat transfer
• BReplace the pressure-relief valve with a plug
• CClose the heater inlet valve completely when jets run
• DInstall a properly adjusted bypass or a dedicated filtered heater loop so heater flow sta…

Why is a corrosion-resistant check valve installed between a spa heater and a downstream chemical feeder?

• ATo increase heater flow above the listed maximum
• BTo serve as the only bonding jumper
• CTo satisfy the gas-code sediment-trap rule
• DTo stop concentrated sanitizer or acid from siphoning back into the heat exchanger when t…

NEC 680.13 requires a maintenance disconnect for outdoor spa equipment to be readily accessible, within sight of the equipment, and at least how far from the water's edge?

• A12 inches
• B3 feet
• C5 feet
• D15 feet

Besides drowning protection, why do installers provide a tight-fitting spa cover?

• ATo replace the need for a circulation pump
• BTo serve as the electrical bonding grid
• CTo raise the maximum legal water temperature above 104°F
• DTo cut heat loss and evaporation so the heater runs less and chemistry stays more stable

What work does a Nevada A-10B Residential Spas license authorize?

• AConstruction and repair of residential spas, including appurtenant equipment
• BConstruction of commercial competition pools only
• CElectrical service upgrades anywhere on the property
• DPublic aquatic-park wave pools

Under NRS 624.920, who may offer to construct a residential spa for a fee in Nevada?

• AAny handy homeowner's neighbor
• BA supplier who only delivers the shell and names an unlicensed installer
• CAn unlicensed salesperson if the contract is under USD 25,000
• DA person who holds a contractor license (or other required authorization) that covers tha…

For a Nevada residential spa contract, what is the maximum initial down payment the contractor may take before construction starts?

• A25 percent of the contract price
• BAny amount the owner agrees to verbally
• CUSD 5,000 regardless of contract size
• DUSD 1,000 or 10 percent of the aggregate contract price, whichever is less

When is a change order on a Nevada residential spa contract enforceable against the owner?

• AWhen the salesperson mentioned it on the phone
• BWhen the extra work is worth less than USD 500
• CWhen the contractor posts it on the job-site trailer
• DWhen it is in writing, clearly states the added scope and price, and is signed by the own…

In addition to the ordinary contractor license bond, what extra security does NRS 624.276 require for contractors who perform residential pool or spa work?

• AA consumer-protection bond or cash deposit solely for the protection of spa and pool cust…
• BA federal performance bond equal to 200 percent of every contract
• CNo bond at all if the contractor has insurance
• DA personal guarantee from the homeowner

NRS 624.520 requires a residential contractor to give the owner written notice of which consumer protection?

• AThe federal estate-tax exemption
• BThe contractor's right to skip permits
• CA waiver of all warranties
• DThe Nevada Residential Construction Recovery Fund