Module 6 of 10
DC & AC design, protection, earthing and lightning
Strings, cables, voltage drop, fuses, SPDs, MCBs, earthing pits and lightning protection.
- 6lessons
- 68minutes
- 2,325questions in the bank
Lessons
String design: Voc at cold mornings, Vmp in summer, MPPT windows
Work out how many modules go in a string so Voc never exceeds the inverter limit on a cold dawn and Vmp stays in the MPPT window on hot afternoons.
11 min read, with a live calculatorDC cables and voltage drop: sizing, colours, routing, UV
Size solar DC cables for current and voltage drop, pick the right cable type, and route it so it survives Indian sun, monkeys and lightning.
10 min read, with a live calculatorProtection: fuses, DC SPD, isolators, AC MCB/RCCB, AC SPD
What each protective device in the DCDB and ACDB does, when you need string fuses, and how to rate fuses, isolators, MCBs, RCCBs and SPDs.
11 min readAC side: cable sizing, phase, connecting at the meter, anti-islanding
Size the inverter's AC cable, choose single or three phase, connect correctly on the consumer side of the net meter, and understand anti-islanding.
11 min read, with a live calculatorEarthing: IS 3043, pits, electrodes, conductor sizes, market practice vs standard
Why PV systems are earthed, what IS 3043 and IEC 62548 expect, and an honest look at Indian practice: separate pits, aluminium cable, chemical rods.
13 min readLightning protection: IS/IEC 62305, LA types, down conductors, separation
Protect a rooftop array from lightning the IS/IEC 62305 way: risk, rod placement by rolling sphere, proper down conductors and the separation distance.
12 min read