CSLB C-46 Solar Contractor flashcards

The process of calculating the required DC power output of a solar array to meet a specific energy demand, considering site-specific factors.

• Determines the total wattage needed from solar panels.
• Accounts for daily energy consumption, peak sun hours, and system losses (derate factor).
• Crucial for meeting client energy goals and optimizing system performance.

Memory trick: Sun's Power Calculates Necessary Array.

Adjusting the angle of a solar collector relative to the horizontal plane to maximize solar energy absorption throughout the year or for a specific season.

• Crucial for system efficiency and output.
• Optimal tilt is often equal to the site's latitude for year-round performance.
• Deviations significantly reduce annual energy capture.

Memory trick: Low temps, sunny skies, check the tilt, where the sun truly lies!

A non-penetrating ballasted PV system anchors solar arrays on flat roofs using weights (ballasts) rather than mechanical fasteners that penetrate the roof membrane, thereby minimizing roof damage and potential leaks.

• Avoids roof penetrations, reducing leak risk.
• Relies on ballast weight to resist wind uplift.
• Requires structural assessment for distributed load capacity.
• Commonly used on large commercial flat roofs.

Memory trick: Penetrations Prevented? Pick a Ballasted, Broadly-Loaded Base.

The optimal tilt angle for a solar collector to maximize annual energy collection is typically set equal to the local latitude.

• Balances summer and winter solar gain.
• Aids in maximizing overall system efficiency throughout the year.
• Adjustments may be made for specific seasonal priorities (e.g., more for winter, less for summer).

Memory trick: Latitude's the guide, for yearly solar tide.

A condition in hydronic systems where trapped air prevents the circulation of fluid, leading to system failure or reduced performance.

• Common in collector loops due to high points where air can accumulate.
• Prevents heat transfer and can lead to collector overheating/stagnation.
• Resolved by proper air purging during installation and maintenance.

Memory trick: When the solar fluid won't flow, trapped air is often the foe.

Standoff refers to the distance between the back of a solar collector and the roof surface, required by code for air circulation, moisture management, and fire safety.

• Prevents heat buildup under the array.
• Allows for drying of moisture and prevents rot.
• Facilitates fire department access and prevents flame spread (fire code).

Memory trick: Standoff's the space, for air and fire's grace.

PV row spacing on flat roofs is the distance between parallel rows of tilted PV modules, primarily calculated to prevent inter-row shading, especially at the lowest sun angles (winter solstice), and to comply with fire code setbacks.

• Critical for maximizing energy production and module density.
• Determined by module height, tilt angle, and site latitude.
• Shadow length is longest at winter solstice solar noon.
• Fire code setbacks (e.g., 3-foot pathways) also dictate spacing.

Memory trick: Shade-free Spacing Secures Solar Success, Especially in Snowy Seasons.

Non-hardware related expenses in a solar project, including customer acquisition, permitting, inspection, financing, and installation labor.

• Can account for a significant portion of total system cost.
• Vary widely by region and project type.
• Efforts to reduce soft costs are crucial for solar affordability.

Memory trick: Hard is what you touch and see, soft is the paperwork fee!

PV conduit aesthetics refers to the visual impact of electrical conduit runs for solar installations, often addressed by minimizing visible exterior runs through strategic routing, concealed pathways, or matching colors to blend with the building's architecture.

• Homeowner aesthetic preferences are a significant factor in residential PV.
• Concealing conduit in attics, walls, or under eaves is preferred.
• If visible, conduit should follow architectural lines and be painted to match.
• Proper planning during site analysis and design phase is crucial.

Memory trick: Conceal Conduit Carefully to Create Client Contentment.

A condition where a heat exchanger fails to transfer heat effectively between two fluids, often due to internal deposits or damage.

• Commonly caused by scaling from hard water or fouling from glycol degradation.
• Results in high collector temperatures but low storage tank gains.
• Requires cleaning or replacement for resolution.

Memory trick: Hot collector, cold tank's woe, heat exchanger's gunk, makes transfer slow!

A pressure test verifies the integrity of solar thermal piping and components by subjecting the system to a pressure higher than its normal operating pressure to detect leaks.

• Typically performed with water or air/nitrogen.
• Commonly tested at 1.5 times the maximum operating pressure.
• Pressure should be held for a specified duration (e.g., 30 minutes to 2 hours) with no significant drop.

Memory trick: Operating pressure up by half, for a leak-free laugh.

The maximum DC voltage permitted for PV systems installed on one- and two-family dwellings, as specified by the National Electrical Code.

• Ensures safety for residential occupants and first responders.
• Defined in NEC Article 690.7(C).
• Differentiates from commercial/utility limits.

Memory trick: Residential is 600, commercial to 1000, safety's the rule, no need to groove!

Ensuring the PV array's maximum open-circuit voltage (Voc) does not exceed the inverter's maximum DC input voltage rating.

• Crucial for inverter safety and longevity.
• Voc increases at lower temperatures, requiring temperature correction.
• A fundamental step in string inverter system design.

Memory trick: Voltage high, inverter cry! Match the limits, keep it dry!

Methods and components used to secure solar PV modules on flat commercial or residential rooftops.

• Ballasted systems use weight to avoid penetrations.
• Mechanically attached systems penetrate the roof membrane.
• Considerations include wind uplift, structural capacity, and roof membrane integrity.

Memory trick: Flat Roofs Need Ballast or Penetrations.

A differential controller in a solar thermal system activates the circulation pump when the collector temperature exceeds the storage tank temperature by a set 'ON' differential, and deactivates it when this difference falls below a set 'OFF' differential, ensuring heat transfer only occurs when beneficial.

• Pump ON: Tc - Ts ≥ Differential ON (e.g., 15°F).
• Pump OFF: Tc - Ts ≤ Differential OFF (e.g., 5°F).
• Ensures efficient heat transfer from collector to tank.
• Faulty sensors are common causes of illogical pump operation.

Memory trick: Temp Difference Drives Pump Logic.

Strategies employed to reduce or eliminate the negative impact of shading on a solar PV system's performance.

• Shading significantly reduces PV system output.
• Direct removal of shade source is often the most effective solution.
• Technological solutions like MLPEs can help mitigate unavoidable shading.

Memory trick: Trees Obscure Sun; Remove or Adapt.

Thermosiphon solar thermal systems rely on natural convection for circulation. Their performance is highly dependent on continuous, unobstructed solar exposure to the collectors, as shading directly reduces the heat input, hindering the natural flow and hot water production.

• Relies on density differences: hot water rises, cold water sinks.
• Collectors must be below the storage tank for proper flow.
• Shading significantly reduces heat gain and circulation.
• No pump is used; circulation is purely passive.

Memory trick: Shade Stops Sun's Hot Flow.

Racking systems designed for flat roofs with limited structural capacity, minimizing added weight and roof penetrations.

• Often uses advanced polymers or minimal metal components.
• Typically non-penetrating to preserve roof integrity.
• Crucial for older buildings or those not designed for heavy loads.

Memory trick: Heavy roof, no go, lightweight polymer, watch it grow!

After filling and pressure testing a closed-loop solar thermal system with a glycol solution, it is essential to verify the concentration of the glycol (for freeze protection and boiling point) and the pH level (for corrosion inhibition) of the heat transfer fluid to ensure system longevity and performance.

• Glycol concentration determines freeze and boil protection.
• pH level indicates corrosion inhibition effectiveness.
• Testing prevents premature system component degradation.
• Use a refractometer for concentration and pH strips/meter for pH.

Memory trick: Fluid Check First, Then Fine-Tune.

The process of subjecting a newly installed solar thermal system to a pressure higher than its normal operating pressure to verify structural integrity and detect leaks.

• Ensures system components and connections can withstand operational stresses.
• Typically performed with water or air before filling with heat transfer fluid.
• Standard minimum test pressure is 1.5 times the operating pressure.

Memory trick: To ensure a solar system is sound, multiply its work by one and a half 'round.

Factors that significantly contribute to the expense of excavating and installing underground conduits for PV systems.

• Labor is often the highest cost for earthwork.
• Soil conditions and terrain impact excavation difficulty.
• Distance and depth of trenching directly correlate with cost.

Memory trick: Digging Labor Costs Most.

A type of bar chart that illustrates a project schedule, showing the start and finish dates of the terminal elements and summary elements of a project.

• Visualizes project tasks over time.
• Shows task dependencies and durations.
• Helps identify the critical path and potential bottlenecks.

Memory trick: Schedule Tasks with Visual Timelines.

Specific requirements for collector loop piping in a solar thermal drainback system to ensure complete fluid drainage.

• All piping must be continuously sloped.
• Prevents freezing and stagnation by draining collectors when pump is off.
• Requires careful attention to eliminate sags or traps.

Memory trick: For drainback's flow, a continuous slope must show, let no water stay, let it all go!

Common issues leading to undesirable noise and vibration in hydronic circulation pumps.

• Air in the system is a primary culprit.
• Can also be caused by cavitation, misalignment, or mechanical wear.
• Requires systematic troubleshooting for resolution.

Memory trick: When the pump makes a ruckus and a hum, check for air, it's often the drum!

A type of thermistor whose electrical resistance decreases as its temperature increases.

• Commonly used as temperature sensors in solar thermal controllers.
• Provides an inversely proportional relationship between resistance and temperature.
• Essential for accurate temperature measurement and system control.

Memory trick: NTC: Negative temp means resistance drops, when the heat just pops!

For a fixed-tilt PV array, the optimal tilt angle for maximizing annual energy production is generally equal to the site's latitude, as this balances seasonal solar exposure.

• Tilt angle = Latitude for annual optimization.
• Steeper angles (Latitude + 15°) favor winter production.
• Shallower angles (Latitude - 15°) favor summer production.
• Consideration for snow shedding may influence tilt in some climates.

Memory trick: Latitude's Light Leverages Long-term Luster.

For PV sites with extensive and unavoidable shading, effective mitigation involves using module-level power electronics (MLPE) to optimize individual module performance and carefully designing the array layout to minimize the impact of shade on system output.

• MLPE (microinverters/optimizers) allows individual modules to operate independently.
• Prevents shaded modules from reducing the output of the entire array.
• Strategic array layout (e.g., splitting arrays, adjusting spacing) minimizes shade impact.
• Shade analysis tools are critical for identifying optimal placement and mitigation strategies.

Memory trick: Complex Conundrums? Choose Clever Component Control and Careful Configuration.

The distance between tilted rows of solar modules on a flat roof, designed to prevent inter-row shading and allow for maintenance access.

• Calculated based on module tilt angle, height, and sun path.
• Critical for maximizing annual energy harvest.
• Also accounts for safe access for cleaning and inspection.

Memory trick: Tilt and space, give modules grace, for sun and for cleaners, a happy place!

Specific hardware required in a PV system to enable power delivery during grid outages.

• Batteries are central to providing backup power.
• Hybrid inverters manage both grid-tied and off-grid operations.
• Automatic transfer switch (ATS) isolates the home from the grid during outages.

Memory trick: Batteries Store Power for Outages.

An inverter that combines the functions of a grid-tied solar inverter and a battery inverter, allowing for direct integration of energy storage.

• Enables self-consumption and backup power.
• Facilitates smart energy management.
• Simplifies system design for battery-integrated PV.

Memory trick: Hybrid's the hero, for battery and home, managing power, never alone!

The process of evaluating the impact of shading objects on a potential solar array location to determine energy production losses.

• Crucial for accurate system sizing and performance predictions.
• Involves identifying shade sources and their annual path.
• Utilizes tools like Solmetric SunEye or drone mapping.

Memory trick: Shade is a problem, but measure it first to avoid a solar squabble!

Designing PV systems for roofs with numerous obstructions by segmenting the array into multiple smaller, independently optimized sections.

• Maximizes module count on complex roofs.
• Often paired with module-level power electronics (MLPE).
• Requires careful layout to avoid self-shading.

Memory trick: Divide and conquer: small arrays fit where one big one can't.

Design considerations for flush-mounted PV systems to minimize visual impact and integrate seamlessly with the architectural style of a building.

• All-black modules blend better with dark roofs.
• Concealed or low-profile racking reduces visual clutter.
• Careful module layout and alignment are important.

Memory trick: Blend PV with the roof: black modules and hidden frames make it disappear.

Strategies for designing a ground-mounted PV system to achieve the lowest Levelized Cost of Electricity by balancing upfront costs with maximized long-term energy production.

• Tilt and azimuth optimization are fundamental and cost-effective.
• Avoid over-spending on marginal gains in efficiency or complexity.
• LCOE considers both CAPEX and OPEX over the system's lifetime.

Memory trick: Smart angles and direction beat fancy tech for the best solar bang for your buck.

An investigation of subsurface soil and rock conditions to provide data necessary for the design of stable and appropriate foundations for ground-mounted PV systems.

• Assesses soil bearing capacity and stability.
• Identifies potential for frost heave or settlement.
• Crucial for foundation selection and design.

Memory trick: Know your ground before you build; soil secrets are key to a stable foundation.

Measures taken to protect ground-mounted PV arrays from environmental threats, wildlife, and unauthorized human access.

• Security is crucial for ground-mount systems due to accessibility.
• Fencing is a primary physical deterrent.
• Consideration of local wildlife is important.

Memory trick: Guard the ground array from critters and creeps with a strong fence.

An inverter that combines grid-tied PV operation with battery charging/discharging and often includes a critical load output for backup power during outages.

• Manages both PV generation and battery storage.
• Provides backup power to a dedicated critical load panel.
• Often more cost-effective for backup than separate components.

Memory trick: Hybrid combines grid-tie and battery, a two-in-one solution for backup needs.

Designing and installing ground-mounted PV systems on uneven or sloped terrain, optimizing for cost, structural integrity, and energy yield.

• Minimizing earthwork saves cost and environmental impact.
• Multi-level racking adapts to contours.
• Structural stability is paramount on inclines.

Memory trick: Slope it, don't flatten it; adapt the array to the land's natural dance.

Calculating the required PV system DC array size to meet a target percentage of a client's annual electricity consumption, considering local production factors.

• Annual consumption is the baseline.
• Target offset percentage determines required annual PV production.
• Divide required production by site-specific kWh/kWp factor to get DC size.

Memory trick: Offset is target usage divided by system yield per kWp.

A non-penetrating PV racking system designed for flat commercial roofs with limited structural load capacity, using minimal ballast to secure the array.

• Avoids roof penetrations to preserve membrane integrity.
• Minimizes added weight on the roof.
• Often uses aerodynamic design to reduce wind uplift forces.

Memory trick: Light, non-penetrating, low-ballast: the feather-touch for fragile roofs.

Cal/OSHA requirements for fall protection when working on a low-slope roof (less than 4:12 pitch) within 6 feet of the roof edge.

• Applies to low-slope roofs (less than 4:12 pitch).
• Mandates conventional fall protection: guardrails, safety nets, or personal fall arrest systems.
• Warning lines with safety monitors are not sufficient for this proximity to the edge.

Memory trick: Six feet close, conventional safety you must propose.

A type of fire extinguisher designed for fires involving energized electrical equipment.

• Uses non-conductive agents (e.g., CO2, dry chemical).
• Essential for safety when dealing with electrical fires.
• Identified by a 'C' symbol on the extinguisher.

Memory trick: Always Be Careful Doing Electrical Work, Kids!

After opening disconnects in a PV system, it is crucial to verify zero voltage at the point of work before touching any conductors or components.

• PV modules can generate voltage even when disconnected from the inverter.
• Zero voltage verification confirms the absence of hazardous electrical energy.
• Use a properly rated and tested voltage meter.
• This step is essential to prevent electrical shock.

Memory trick: Disconnect, Verify, Ground, Work safely all around!

Optimizing ground-mounted PV systems for low O&M costs prioritizes designs that facilitate easy cleaning and vegetation management.

• Vegetation encroachment can cause shading and damage.
• Dust and dirt reduce module efficiency, requiring cleaning.
• Design for ease of access and maintenance significantly lowers recurring costs.

Memory trick: Keep it clean, keep it clear, keep costs low.

The operational rule for a solar thermal differential controller to activate the circulating pump when the collector temperature exceeds the storage tank temperature by a set 'ON' differential.

• Compares collector and tank temps
• Activates pump when ΔT > ON setting
• Transfers heat from collector to tank
• Prevents reverse thermosiphon

Memory trick: Collector hot, tank is cold; differential met, pump takes hold.

The maximum pressure at which a pressure relief valve (PRV) on a potable water heater is permitted to open, as regulated by the Uniform Plumbing Code (UPC), to prevent dangerous over-pressurization.

• Ensures safety of the water heater and plumbing system.
• Protects against excessive internal pressure.
• Mandatory safety device for all potable water heaters.

Memory trick: Safe water pressure keeps the hot water flowing, not blowing.

A National Electrical Code (NEC) rule that limits the combined overcurrent protection device (OCPD) ratings for a service with interconnected power sources (like PV) to a maximum of 120% of the service busbar's continuous current rating, ensuring the busbar is not overloaded.

• Applies to supply-side and load-side connections.
• Prevents busbar overload from simultaneous utility and PV power.
• Formula: (1.20 * Busbar Rating) >= (Main OCPD + PV OCPD).

Memory trick: One-twenty percent of power protects the panel from peril.

Battery Energy Storage Systems (BESS) are essential for energy arbitrage and Virtual Power Plant (VPP) participation, enabling energy storage and strategic dispatch.

• Arbitrage: Buy energy when cheap, use/sell when expensive.
• VPP: Aggregate distributed energy resources for grid services.
• BESS provides the flexibility to store and release energy on demand.

Memory trick: Arbitrage and VPPs need batteries to mediate.

The accumulation of deposits (scale, sludge, corrosion products) on the surfaces of a heat exchanger, which reduces its efficiency and can impede fluid flow.

• Reduces heat transfer rate
• Causes increased pressure drop
• Leads to collector overheating/stagnation
• Requires cleaning or replacement

Memory trick: Collector boils, tank is cold; heat exchanger's story untold.

A condition where a solar thermal circulating pump rapidly turns on and off, often due to insufficient fluid flow, leading to inefficient heat transfer and premature pump wear.

• Pump turns on/off rapidly
• Commonly caused by low flow
• Can result from air locks, closed valves, or undersized pump
• Reduces system efficiency and component lifespan

Memory trick: Pump goes 'on!', then 'off!', then 'on!' again; low flow's the culprit, a heating pain.

When using an extension ladder to access an upper landing surface, the ladder must extend at least 3 feet above that surface.

• Ensures a stable handhold for safe transfer.
• Applies to all ladders used for accessing elevated platforms.
• Prevents falls during ascent and descent.

Memory trick: Three feet up, you're safe and sound, for climbing ladders all around.

The minimum slope required for solar thermal collector headers and piping to facilitate fluid drainage and air removal.

• Prevents air pockets
• Ensures complete drainage (e.g., for freeze protection)
• Standard minimum is 1/8 inch per foot

Memory trick: Pitch the pipe, lest air it grip.

Lead-acid batteries can emit hazardous gases like hydrogen (flammable) and hydrogen sulfide (toxic, 'rotten egg' smell) during overcharging or malfunction.

• Hydrogen is highly flammable and explosive.
• Hydrogen sulfide is toxic and has a distinct rotten egg odor.
• Requires proper ventilation and monitoring in battery enclosures.

Memory trick: Rotten eggs mean battery's plight, sulfuric acid's giving a fright!

A hybrid inverter combines grid-tied and battery-based functionalities, enabling solar self-consumption, grid export, and automatic backup power during outages.

• Manages power flow between solar, battery, loads, and grid.
• Allows for energy storage and strategic discharge.
• Provides seamless transition to backup power during outages.

Memory trick: Hybrid's the hero for both grid and blackout.

Aesthetic integration of PV systems is achieved through mounting solutions that minimize the visual profile, such as low standoff, flush-mount designs.

• Flush mounting reduces the gap between modules and roof.
• Minimizes the visual impact of the array.
• Important for homeowner satisfaction and property value.

Memory trick: Flush to the roof, keeps it smooth.

The process of using a refractometer to measure the percentage of glycol in a heat transfer fluid to ensure it provides adequate freeze protection for solar thermal systems.

• Uses a refractometer
• Measures refractive index
• Correlates to freeze point
• Crucial for winter operation

Memory trick: For glycol's freeze, a refractometer's ease.

The breakdown of propylene or ethylene glycol in solar thermal systems due to prolonged exposure to high temperatures, leading to reduced heat transfer efficiency and system damage.

• Causes fluid to turn dark brown/black
• Produces a burnt odor
• Forms acidic byproducts and sludge
• Reduces heat transfer effectiveness

Memory trick: Brown and burnt, a high temp fright; glycol's broken, lost its light.

A Secure Power Supply (SPS) inverter allows direct power from the PV array to a dedicated outlet during grid outages, providing limited daylight-only backup without a battery.

• Provides power only when sun is shining and grid is down.
• Typically limited to a single dedicated outlet and specific loads.
• More cost-effective than full battery backup.

Memory trick: SPS: Sun Power Saver for outages.

A device installed at the highest point of a drainback solar thermal collector array that allows air to enter the system, breaking the vacuum and enabling the heat transfer fluid to drain back to the reservoir.

• Crucial for proper drainage
• Installed at highest point
• Prevents fluid from being held in collectors
• Essential for freeze and stagnation protection

Memory trick: Drainback's secret, a vacuum's end; air in, fluid descends.

Designing PV systems for future expansion involves oversizing key electrical infrastructure components like inverters and wiring to accommodate additional modules later.

• Avoids costly and disruptive upgrades of core electrical components.
• Requires careful planning of conduit runs and panel space.
• Often involves higher upfront cost for oversized components but saves long-term.

Memory trick: Plan for growth, oversizing's the path.