CSLB C-46 Solar Contractor flashcards

NEC 690.8(A)(1) mandates that PV system circuit conductors must be sized to carry a minimum of 125% of the maximum continuous current to account for potential sustained loads.

• Applies to PV system circuit conductors (DC and AC).
• Calculated as 125% of the maximum continuous current.
• Ensures conductors can handle sustained operational currents without overheating.

Memory trick: Always Multiply Current by 1.25 for PV Conductors.

An unintended electrical discharge (spark) that occurs in a DC circuit, often caused by loose connections, damaged insulation, or compromised conductors.

• Significant fire hazard.
• Commonly caused by loose connections or damaged wiring.
• PV systems require arc-fault circuit interrupters (AFCI) for detection.

Memory trick: Loose connections spark trouble, arcs are the main peril.

A semiconductor device placed in series with a PV string or array to prevent reverse current flow from the load (e.g., battery, inverter) back into the PV modules, which could cause damage or discharge.

• Ensures one-way current flow.
• Prevents module discharge at night.
• Protects against reverse current during faults.

Memory trick: Blocking stops the backflow, bypass jumps the shade.

When damaged electrical wiring (e.g., cracked insulation) is encountered, the immediate protocol is to de-energize the affected circuit and report the hazard to a supervisor or qualified electrician.

• Cracked insulation exposes live conductors.
• Poses shock and fire hazards.
• De-energize first, then report for proper repair.

Memory trick: Cracked wire, immediate retired.

An unintended electrical discharge (arc) between two conductors or a conductor and ground in a DC circuit, often caused by loose connections, damaged insulation, or compromised wiring.

• Generates intense heat and can cause fires.
• Visible signs include burn marks, melted insulation, carbonization.
• Detected by Arc Fault Circuit Interrupters (AFCI) in modern PV systems.

Memory trick: Faults: Arc, Ground, Short, Open

Cal/OSHA requires employers to submit written notification to the Division of Occupational Safety and Health at least 24 hours prior to starting any asbestos-related work that disturbs asbestos-containing materials.

• Mandatory for 'asbestos-related work'.
• Ensures regulatory oversight and compliance.
• A critical administrative control to prevent uncontrolled exposure.

Memory trick: Before you touch asbestos, tell Cal/OSHA, it's a must-do!

OCPDs, like fuses and circuit breakers, must be correctly sized to protect electrical conductors and equipment from damage due to excessive current, ensuring they trip before damage occurs.

• Protects against overloads and short circuits
• Must be rated appropriately for the circuit's ampacity and equipment's maximum current
• Oversizing prevents proper protection; undersizing causes nuisance tripping

Memory trick: Circuit's fiery guard, sized just right, saves the day, or ignites the night.

For continuous loads (operating for 3 hours or more), the overcurrent protective device must be sized at not less than 125% of the maximum continuous current.

• Applies to AC output circuits of inverters.
• Prevents nuisance tripping and ensures safety for sustained operation.
• Conductors are also sized to account for continuous loads.

Memory trick: Inverter's AC output needs 125% 'safety buffer' for continuous flow!

Insulating gloves are classified by their maximum use voltage, with Class 0 (1,000V) being the minimum recommended for working on common commercial voltages like 208V or 480V.

• Classes range from 00 to 4, with increasing voltage ratings.
• Leather protectors must always be worn over insulating gloves.
• Gloves must be regularly inspected and tested.

Memory trick: For 208V, Class Zero is your hero, keeping shocking risks near zero!

Electronic components (diodes) integrated into PV modules or junction boxes that shunt current around shaded or faulty cells/modules, preventing hot spots and minimizing power loss in a string.

• Prevents reverse bias and hot spot formation.
• Improves system performance under non-uniform irradiance.
• Typically found in module junction boxes, often in groups of 2-3 per module.

Memory trick: Shading Solutions: Bypass, Optimize, Separate

The Limited Approach Boundary (LAB) is the closest an unqualified person can approach exposed energized electrical conductors or circuit parts. For 50V-750V, it is 10 feet.

• Protects unqualified personnel from arc flash and shock.
• Unqualified persons must not cross the LAB unless escorted.
• LAB varies based on voltage levels.

Memory trick: Ten feet for the 'un-qual', stay far, stay safe, don't fall!

For continuous PV system currents, the current used to determine the minimum overcurrent protection device (OCPD) rating must be multiplied by 125%.

• Applies to continuous currents (3 hours or more).
• Ensures OCPD does not trip prematurely.
• Calculated current determines the minimum standard OCPD size.

Memory trick: NEC Sizing: Continuous Current + 125% = OCPD

The process by which a grid-tied inverter checks that the utility grid's voltage and frequency are within acceptable operational ranges before connecting and exporting power.

• Ensures safe and stable interconnection with the utility grid.
• Prevents damage to the PV system and disruption to the grid.
• A mandatory step dictated by grid codes (e.g., IEEE 1547).

Memory trick: Grid parameters check, before you connect the power deck!

Requires PV system circuit conductors to have an ampacity of at least 125% of the maximum continuous current they are expected to carry.

• Applies to both DC and AC PV circuits.
• Accounts for continuous operation and potential variations in current.
• Ensures conductors do not overheat, preventing fire hazards and insulation degradation.

Memory trick: For PV wires, multiply by one-point-two-five, to keep the circuit alive!

For safe ladder setup, the base of the ladder should be placed 1 foot away from the wall for every 4 feet of vertical height to the point of support, resulting in approximately a 75-degree angle.

• Ensures stability and reduces slipping/tipping.
• Applies to portable extension and straight ladders.
• Always ensure proper footing and tie-off if possible.

Memory trick: Four up, one out, keeps the ladder safe, no doubt!

Configuration of an inverter to comply with local utility requirements for voltage, frequency, and other grid interaction parameters.

• Ensures safe and stable interconnection with the utility grid.
• Incorrect settings can lead to nuisance tripping and system downtime.
• Must match the specific grid standards of the installation location.

Memory trick: Grid codes must match, or the inverter will detach!

Carbon monoxide poisoning occurs when CO displaces oxygen in the blood, leading to symptoms like headache, dizziness, nausea, fatigue, and confusion, often mistaken for flu.

• CO is colorless, odorless, and tasteless.
• Produced by incomplete combustion.
• Symptoms worsen with exposure duration and concentration.

Memory trick: Dizzy, headachy, feeling ill? Check for CO, it's a silent kill!

Ensuring a continuous, low-impedance metallic path from all non-current-carrying metal parts of the PV system back to the main service grounding electrode system.

• Prevents electric shock hazards by safely clearing ground faults.
• Requires dedicated equipment grounding conductors or approved metallic raceways/racking.
• Utility water pipes are generally not reliable for equipment grounding due to potential interruptions.

Memory trick: Grounding must be sound and true, a continuous path for safety too!

The reduction in voltage between the inverter's AC output and the point of interconnection due to resistance in the AC conductors.

• Increases with conductor length and current.
• Decreases with larger conductor gauge.
• Can cause inverters to trip on undervoltage errors.

Memory trick: Long wires, small gauge, voltage drain, inverter in pain.

For continuous currents in PV systems, the conductors must have an ampacity not less than 125% of the maximum continuous current.

• Applies to both DC and AC PV circuits that carry continuous current.
• Ensures conductors do not overheat under prolonged load.
• Calculated ampacity must then be matched to appropriate wire gauge.

Memory trick: Conductor Sizing: Continuous Current * 1.25

A test to measure the electrical resistance between current-carrying conductors and ground to ensure proper insulation and detect unintended current paths.

• High resistance (e.g., >1 Mohm) indicates healthy insulation.
• Low resistance indicates a ground fault.
• Crucial for safety and system performance, preventing shock hazards and equipment damage.

Memory trick: High resistance, no ground fault; low resistance, then halt!

Verifying the correct positive and negative terminals of a PV string using a multimeter before connection to prevent damage.

• Crucial before connecting to inverter or combiner box.
• Positive voltage from positive to negative is correct.
• Reversed polarity can damage inverters.

Memory trick: Positive to negative, a positive sign means it's fine!

Limits the total current that can be supplied to a busbar by both the utility and PV system to 120% of the busbar's rating.

• Ensures the busbar is not overloaded by combined utility and PV current.
• Formula: (Busbar Rating * 1.2) - Main Breaker Rating = Max PV OCPD.
• Critical for safe interconnection of PV systems to existing electrical panels.

Memory trick: Busbar's 120% limit, keep the total current fit!

Portable generators must be properly grounded to provide a safe path for fault currents, protecting users from electric shock in the event of an insulation failure or other electrical fault.

• Crucial for preventing electric shock.
• Connects the generator's frame to an earth ground.
• Required by NEC and OSHA for most applications.
• Often involves a grounding rod or connection to a building's grounding electrode system.

Memory trick: Genie's power, safely bound, with a solid wire to the ground.

A 'Grid Undervoltage' error on a grid-tied inverter can be caused by undersized AC output conductors, which result in excessive voltage drop (or voltage rise) between the inverter and the point of interconnection, making the inverter sense a lower-than-actual grid voltage.

• Inverters monitor grid voltage for safe operation.
• Voltage drop in AC conductors reduces the voltage available at the inverter terminals.
• Excessive voltage drop can make the inverter falsely detect a grid undervoltage.
• Proper conductor sizing (NEC 210.19(A)(1) & 690.8) is crucial to prevent this.

Memory trick: Tiny Wires Make Tiny Volts, Triggering Trip-Outs.

The practice of connecting all non-current-carrying metallic components of a PV system to the earth via a low-resistance path to prevent electric shock and dissipate fault currents.

• Required by NEC for safety.
• Protects against electric shock during ground faults.
• Ensures proper operation of overcurrent protection devices.

Memory trick: Grounding's your shield: 'Shock Stopper' and 'Fault Fighter'!

Devices like microinverters and DC optimizers that perform MPPT and power conversion at the individual PV module level.

• Optimizes power for each module independently.
• Excellent for mitigating partial shading.
• Can provide module-level monitoring.

Memory trick: Small shade, big problem? Module-level tech is the best solution.

NFPA 70E categorizes arc flash hazards and specifies corresponding PPE based on calculated incident energy levels to protect workers from burns.

• Categories (CAT 1-4) correlate to incident energy (cal/cm²).
• PPE must meet or exceed the Arc Thermal Performance Value (ATPV) for the category.
• A full arc flash risk assessment is required to determine the category.

Memory trick: Each cal/cm² is a 'CAT' step up, protecting you from arc flash's hot cup!

Effective PPE for outdoor workers exposed to sun includes light-colored, long-sleeved clothing, wide-brimmed hats, and high-SPF sunscreen to prevent UV damage and heat-related illnesses.

• Physical barriers are superior to sunscreen alone.
• Wide-brim hats protect face, neck, and ears.
• SPF 30+ is recommended for exposed skin.

Memory trick: Long sleeves, wide brim, high SPF; stay cool, stay safe, live free!

Protection against falling objects includes engineering controls (e.g., toe boards, nets) and personal protective equipment (PPE) such as hard hats for workers in the fall zone.

• Hard hats protect the head from impact.
• Toe boards prevent objects from falling off edges.
• Safety nets catch falling objects.
• Barricading areas below work also prevents injury.

Memory trick: Object drops, hard hat stops.

The initial step in a Lockout/Tagout procedure requires informing all affected employees that machinery or equipment will be shut down and locked out to prevent accidental energization.

• Ensures worker awareness and safety.
• Prevents unexpected startups.
• Applies to all personnel who might be affected by the LOTO.

Memory trick: Notify, Shut, Lock, Test: The LOTO steps, put to the test!

A diode placed in series with a PV string or array to prevent reverse current flow from other strings, the inverter, or a battery bank into a specific string, especially when shaded or underperforming.

• Also known as isolation diodes.
• Protects strings from becoming a load.
• Common in multi-string systems and battery-based systems.

Memory trick: Diodes Direct Current

Arc-rated (AR) clothing is Personal Protective Equipment (PPE) designed to protect workers from the thermal hazards of an electric arc flash.

• Protects against intense heat and radiant energy.
• Reduces burn injury severity.
• Rated by Arc Thermal Performance Value (ATPV) or Energy Breakopen Threshold (EBT).

Memory trick: Arc flash heat, AR clothes can beat.

A PV mounting system for flat roofs that uses weighted ballast blocks to secure the array against wind forces, avoiding roof penetrations.

• Primarily used on low-slope or flat commercial roofs.
• Eliminates roof penetrations, preserving roof integrity.
• Requires careful calculation of ballast weight based on wind loads.

Memory trick: Ballast: The 'Weighty Watchman' against wind, saving the roof!

The reduction in voltage between the inverter's AC output and the utility grid's point of interconnection, primarily due to resistance in the AC conductors.

• Can cause inverters to trip on undervoltage or overvoltage (voltage rise).
• Leads to reduced system performance and energy harvest.
• Mitigated by properly sizing conductors for current and distance.

Memory trick: Thin wires make voltage low, causing the inverter to disconnect and go!

Sizing an off-grid PV array involves calculating daily energy demand, accounting for system losses (derate factor), and determining the number of modules needed based on peak sun hours.

• Daily energy demand (Wh/day) is the starting point.
• System derate factor accounts for all losses (temperature, wiring, inverter, dirt, etc.).
• Peak Sun Hours (PSH) represent the equivalent hours of full sun irradiance.
• Always round up the number of modules to meet demand.

Memory trick: Demand, Derate, PSH, Modules: Don't Forget Power System Math!

OSHA requires employers to provide fall protection to employees working at heights of 6 feet or more above a lower level.

• Applies to general industry and construction.
• Methods include guardrails, safety nets, and personal fall arrest systems.
• Specific rules apply for different work environments like roofing.

Memory trick: Six feet high, safety's nigh!

For safe access to an elevated work surface, a ladder must extend at least 3 feet (0.9 meters) above the landing point to provide a stable handhold for workers transitioning on and off the ladder.

• 3-foot extension is a safety standard.
• Provides a stable grab point for climbing on/off.
• Prevents overreaching or loss of balance.
• Applies to all types of ladders accessing elevated surfaces.

Memory trick: Three feet high, for safety in your eye.

Strategies and technologies used in PV systems to minimize energy losses caused by shadows on a portion of the solar array.

• Shading can drastically reduce PV system output.
• Microinverters and power optimizers are effective solutions.
• Physical layout adjustments are the first step.

Memory trick: Shading's a snag, but smart tech brings power back!

Method where the weight of ballast material (e.g., concrete blocks) is distributed across a PV racking system to counteract wind uplift forces without penetrating the roof.

• Primarily used on flat roofs.
• Minimizes roof penetrations, reducing leak risks.
• Ballast weight calculations are critical for structural integrity.

Memory trick: Wind Resistance: Weight, Weld, or Wedge

Requires overcurrent protection devices (OCPDs) for PV circuits to be sized at not less than 125% of the maximum continuous current, then rounded up to the next standard OCPD size.

• Ensures OCPDs can handle continuous loads without nuisance tripping.
• Protects conductors and equipment from overcurrents.
• Requires knowledge of standard OCPD sizes (e.g., 15, 20, 25, 30, 35, 40, 50A).

Memory trick: Multiply by 1.25, then round up, for safe circuit setup!

Degradation where the encapsulant layers separate from the glass or backsheet, allowing moisture to enter the module, leading to corrosion, browning, and power loss.

• Visible as discoloration, browning, or 'snail trails'.
• Often starts at module edges or defects.
• Accelerated by humidity and temperature cycling.

Memory trick: Degradation: PID, LID, Cracks, or Wet

The practice of electrically bonding the non-current-carrying metal parts of PV modules and their support structures to an equipment grounding conductor.

• Prevents electric shock hazards.
• Required by NEC 690.43.
• Ensures fault current has a safe path to ground.

Memory trick: Grounding Code ensures safety, always bond the frame.

A National Electrical Code rule governing the maximum allowable current for PV systems connected to a service panel's busbar, ensuring the busbar is not overloaded.

• Sum of utility OCPD and PV OCPD must not exceed 120% of busbar rating.
• Applies to supply-side connections.
• Critical for preventing busbar overheating and ensuring safety.

Memory trick: Busbar's '120% Limit' keeps the power flow safe and sound!

The sequence of steps to safely and correctly bring an AC-coupled microinverter PV system online after installation.

• Prioritize AC connection to establish grid reference.
• Each microinverter operates independently.
• No central DC disconnect is typically required due to rapid shutdown compliance.

Memory trick: AC first, then DC, then monitor the flow!

Connecting batteries positive-to-negative to increase the total system voltage while maintaining the same amp-hour capacity.

• Total voltage = sum of individual battery voltages.
• Total amp-hours = amp-hours of a single battery.
• All batteries must have the same voltage and capacity.

Memory trick: Series for Voltage, Parallel for Amps, always remember the 'V' and 'A' maps!

The low-resistance electrical connection between all non-current-carrying metal parts of a PV system and the equipment grounding conductor, ensuring a safe path for fault currents.

• Critical for electric shock prevention.
• Industry best practice: ≤ 1 Ohm.
• Ensures effective operation of overcurrent protection devices.

Memory trick: Equipment ground: One Ohm or less, for safety's best success.

An inverter error indicating a problem with the connection to, or conditions of, the utility grid.

• Prevents inverter from feeding power to the grid.
• Can be caused by open AC disconnects, utility outages, or incorrect grid parameters.
• Requires verifying AC connections and utility status.

Memory trick: Grid Fault means check the 'AC-side' first, from inverter to meter!

A bypass diode failing in a short-circuit condition, effectively bypassing a portion of the PV module cells and reducing the module's output voltage.

• Reduces module voltage contribution.
• Can lead to reduced string Voc and power output.
• Often difficult to detect without IV curve tracing or individual module testing.

Memory trick: Low Voc? Check for 'Bypassed Blocks' or bad connections!

Selecting the best stationary angle for PV modules to maximize annual energy yield, often approximated by the site's latitude.

• Tilt angle affects solar irradiance interception.
• Latitude is a common starting point for fixed tilt.
• Adjustments can be made for seasonal prioritization (e.g., more winter or summer production).

Memory trick: Latitude's your guide for annual gain, but seasons shift the sun's domain!

The phenomenon where the voltage at the inverter's output terminals increases above the utility's nominal voltage, typically due to impedance in the AC interconnection circuit when power is being exported.

• Caused by resistance in AC wiring, breakers, or utility infrastructure.
• Leads to 'High Grid Voltage' errors and inverter shutdowns.
• Mitigated by proper conductor sizing and minimizing circuit length.

Memory trick: High Grid Voltage? The 'AC Resistance Roadblock' is the culprit!

Conductors routed through conduits, especially metal conduits exposed to direct sunlight, can experience elevated temperatures that accelerate insulation degradation and reduce current carrying capacity.

• Sunlight heats conduit, transferring heat to conductors.
• High temperatures reduce conductor ampacity.
• Excessive heat causes insulation to become brittle and crack.

Memory trick: Hot Conduits Cook Insulation.

An N95 respirator is a NIOSH-approved filtering facepiece respirator that filters at least 95% of airborne particles (non-oil-based), used for protection against dusts, mists, and biological aerosols.

• Requires fit-testing for proper seal.
• Not for gases or vapors.
• Must be part of a comprehensive respiratory protection program.

Memory trick: N-95 for dust and bugs, keeps your lungs safe from airborne hugs!

The process of selecting the correct number of PV modules in series to match the voltage operating window of a specific inverter or charge controller.

• Open-circuit voltage (Voc) is additive in series.
• Voltage must stay within inverter's min/max operating range.
• Temperature significantly affects Voc (Voc increases at colder temperatures).

Memory trick: Series = Voltage, Parallel = Current

Cal/OSHA requires fall protection for employees working on roofs with a slope greater than 4:12 (vertical to horizontal ratio).

• Slope greater than 4:12 requires fall protection.
• Guardrails, safety nets, or personal fall arrest systems are common methods.
• Applies to all roofing work where fall hazards exist.

Memory trick: Four-to-Twelve: Fall Protection is the Rule to Thrive.

Microinverters optimize power at the individual module level, effectively mitigating the impact of partial shading by ensuring that only shaded modules experience reduced output, while others continue to produce maximally.

• MPPT is performed for each individual module.
• Shading on one module does not affect the performance of other modules.
• Maximizes energy harvest in complex or shaded layouts.
• Higher initial cost but often better performance in challenging conditions.

Memory trick: Microinverters Make Minimizing Shading Maximize Output.

For PV inverter output circuits, the conductor ampacity must be at least 125% of the maximum inverter output current.

• Applies to continuous loads.
• Ensures conductors can safely handle sustained current.
• Calculated current is multiplied by 1.25.

Memory trick: Current's high, so multiply by one point twenty-five (1.25) to size the wire right.

The process of using a multimeter to confirm the correct positive and negative terminals of a PV string before connection to an inverter or charge controller.

• Crucial to prevent damage to PV equipment.
• Typically done with a digital multimeter (DMM) in DC voltage mode.
• Incorrect polarity can lead to short circuits or inverter failure.

Memory trick: Many Tools Measure Everything

Protection against electric shock from portable electric tools is primarily achieved through double insulation or proper grounding (using a three-prong plug with a grounded outlet or GFCI).

• Double insulation provides two layers of insulating material.
• Grounding creates a low-resistance path for fault currents.
• Ground Fault Circuit Interrupters (GFCIs) also provide shock protection.
• Regular inspection for damaged cords/housing is crucial.

Memory trick: Double or ground, shock won't be found.

Corrosion on a grounding electrode conductor (GEC) impairs its ability to provide a low-impedance path for fault currents to safely dissipate into the earth, creating a significant electrical shock and fire hazard.

• Compromises the entire grounding system.
• Prevents circuit breakers/fuses from tripping correctly during a fault.
• Increases risk of step/touch potentials during lightning or ground faults.

Memory trick: Corroded ground wire? Fault path's broken, danger's higher!