Exam: size and wire a system for this home
A family in Lapu-Lapu: a two-door refrigerator, six LED lights for six hours at night, two fans for ten hours (mostly at night), a 43" TV for five hours in the evening and a Wi-Fi router, all on the bench and labelled. Give them solar that carries the night. Budget ₱180,000 at the studio’s prices. Pass the safety check with zero fails, and the night test run.
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How it works
Graded on:
- Safety check: zero fails
- Every labelled load has power (220 V at the AC loads, 12 V at the router)
- The night test run passes on this exact wiring (⏱ Test run → The night)
- Estimated cost under ₱180,000 (the studio’s prices)
Build on this bench, then press Check my design on the exam card. 40 minutes is the target; attempts and time are kept in your transcript. Hints cost nothing but are noted.
Parts on the bench
More on solar pv physics
- The IV curve: Voc, Isc and the knee
- Cold mornings raise Voc; hot noons cut power
- Shading and bypass diodes: a shadow costs more than its size
- A string against the controller: the cold-morning Voc
- PWM against MPPT: the harvest, as a number
- Lead-acid against LiFePO4: usable capacity, voltage and life
- Wiring, fuses and breakers for an array: the 1.25 and 1.56 rules
- Grounding, bonding and surge protection: the two jobs of earth