Punjab PSEB Sr. Sec. NSQF Electronics (Solar Panel Installation Technician) flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Standard Test Conditions

Reference conditions for PV ratings: 1000 W/m² irradiance, 25 °C cell temperature, and AM 1.5 spectrum. Nameplate power, voltage and current are quoted at STC.

Fill factor

Ratio of maximum power to the product of open-circuit voltage and short-circuit current: FF = (Impp × Vmpp) / (Isc × Voc). Higher fill factor means a squarer, better I-V curve.

Open-circuit voltage

Voltage across a module terminals with no load connected, measured in volts. It rises slightly in cold weather and falls as cell temperature increases.

Short-circuit current

Current that flows when module terminals are connected through a near-zero resistance. It scales almost linearly with irradiance and is used to check string health.

Photovoltaic effect

Generation of voltage and current when light strikes a semiconductor junction. Photons create electron-hole pairs that the built-in electric field separates.

Peak sun hours

Number of hours per day at 1000 W/m² equivalent irradiance. Daily energy yield is roughly array kWp times peak sun hours times performance ratio.

Monocrystalline module

Module made from single-crystal silicon cells, usually black and uniform. Efficiency is typically 18-23 %, giving the highest power per square metre.

Polycrystalline module

Module made from multi-crystalline silicon with visible grain boundaries and a bluish look. Efficiency is typically 15-18 %, with lower cost than monocrystalline.

Thin-film module

Module using CdTe, CIGS or amorphous silicon layers. Efficiency is lower (6-13 %) but it is flexible, lightweight and performs relatively better in high heat and low light.

Bypass diode

Diode connected across a group of cells in the junction box. It provides an alternate current path when cells are shaded, limiting hot-spot heating and power loss.

Potential-induced degradation

PID is a voltage-driven module degradation that reduces power, often from leakage currents between cells and frame. It appears as shunting and can be tested by flash test.

Maximum series fuse rating

Datasheet value giving the largest fuse permitted in series with a module or string. String fuses must not exceed this rating to protect the module.

Load assessment

Inventory of every appliance with wattage, daily hours and quantity. Daily energy in Wh equals the sum of watts times hours times quantity.

Optimum tilt angle

Angle of the array from horizontal that maximises annual yield, roughly equal to site latitude. Adjusting latitude minus 10-15° favours summer generation.

Shading analysis

Study of shadows on the array through the day and year, especially 9:00-15:00. It identifies obstructions and sets row spacing or module repositioning.

Depth of discharge

Fraction of battery capacity that may be withdrawn before recharging. Lead-acid is usually limited to 50 %, while LFP batteries allow 80-90 %.

Voltage drop

Loss of voltage along a cable due to resistance. For a two-wire DC run, Vdrop = 2 × L × I × ρ / A; keep DC drop within 3 %.

Mid-clamp

Mounting clamp that grips the frames of two adjacent modules and fixes them to the rail. It is torqued to the manufacturer specification, commonly 16-20 N·m.

Wind uplift load

Upward force on the array caused by wind passing over it. Design pressure uses p = 0.6 × Vz², with higher values at roof edges and corners.

Module handling rule

Carry modules upright with two persons, never stand or place tools on the glass, and store on edge on a padded surface to avoid micro-cracks.

MC4 connector

Locking DC connector used for module and string wiring. Only mate identical types, crimp with the correct tool, and never disconnect under load.

String fuse

Fuse placed in series with each string in the combiner box. It protects the module and cabling from reverse currents and must not exceed the module maximum series fuse rating.

Earthing and bonding

Connection of module frames, structure, inverter and enclosures to a common earth electrode. Earth continuity resistance is typically kept below 1 Ω.

Surge protective device

Device that diverts lightning or switching surges to earth. Type 2 DC SPDs are fitted on the DC side and Type 2 AC SPDs on the AC side.

Anti-islanding

Grid-tied inverter function that stops export within a set time when the grid fails. It protects utility workers and is tested during commissioning per IEC 62116.

MPPT charge controller

Controller that continuously adjusts operating voltage to the array maximum power point. Efficiency is typically 93-98 %, higher than PWM controllers.

Hybrid inverter

Inverter that works with the grid and a battery bank, supporting self-consumption, export and backup. Sizing must check MPPT count and battery voltage compatibility.

Insulation resistance test

Measurement of resistance between DC conductors and earth using a megger at 500-1000 V. A reading below about 1 MΩ indicates cable damage or moisture.

Clamp meter current check

Measurement of DC current in each string under load. Comparing strings after correcting for irradiance reveals a dead string, mismatch or partial shading.

Performance ratio

Ratio of actual energy yield to theoretical yield at STC for the same irradiance. Typical values are 0.70-0.85; below 0.70 signals a problem.

Lockout/tagout

Safety procedure that isolates AC and DC supplies, applies a personal lock and tag, and verifies zero voltage before work. Only the applier removes the lock.

Battery and e-waste disposal

Used modules, inverters and batteries must go to authorised recyclers under the E-Waste and Battery Waste Management Rules. Burning or landfilling is prohibited.