New Curriculum Second Term Solar PV Installation and Maintenance examination for SS 1

Class: SS 1
Term: Second Term
Subject: Solar PV Installation and Maintenance
Time: 2 hours
Total Marks: 70

SECTION A: OBJECTIVES (40 Marks)
Instruction: Answer all questions. Each question carries 1 mark. Choose the best option (a), (b), (c) or (d).

1. All are reasonable safe-installation steps except ________. (a) checking equipment labels    (b) keeping access to emergency isolation    (c) using appropriately rated instruments    (d) performing terminal checks with wet hands
2. A clinic increases its storage autonomy target from one day to three at the same load. Which effect is expected? (a) Required usable storage energy increases approximately threefold    (b) Battery capacity requirements fall to one-third    (c) Daily demand becomes zero    (d) Panel voltage automatically triples
3. An installer notices overheating and a burning odour. The first appropriate response is ________. (a) increase load to test the fault faster    (b) stop work, keep people clear and follow safe isolation/emergency procedures    (c) cover vents to reduce noise    (d) ignore the smell if output remains normal
4. Which calculation correctly finds energy demand from appliance labels? (a) Add power ratings without considering time    (b) Multiply voltage by the number of days alone    (c) Sum each appliance’s power multiplied by its use duration    (d) Divide hours by the panel’s advertisement size
5. The correct step before touching inverter terminals during training is ________. (a) to establish and verify safe isolation using the approved procedure    (b) to touch them briefly with unprotected fingers    (c) to trust a dark display as proof of no stored energy    (d) to bypass the protective switch
6. A shop uses two 30 W lamps for 5 hours. Their combined energy use is ________. (a) 60 Wh    (b) 150 Wh    (c) 300 Wh    (d) 600 Wh
7. Which label should NOT be ignored when matching an inverter to a system? (a) Permitted DC input voltage and AC output ratings    (b) Outer carton dimensions alone    (c) Only peak power while ignoring DC-input compatibility    (d) Only the product price, ignoring continuous output and surge limits
8. A customer confuses a standalone inverter with a complete solar system. The correct explanation is ________. (a) An inverter creates daylight    (b) An inverter contains an unlimited battery    (c) An inverter eliminates protective devices    (d) An inverter converts power but generation, control and possibly storage remain separate requirements
9. A household uses a battery-based inverter rather than a grid-only inverter. The main operational difference is ________. (a) it automatically requires no battery wiring    (b) its architecture is designed to work with appropriate storage and supported operating modes    (c) it converts all electrical energy into sunlight    (d) it cannot supply alternating-current loads
10. Why can a motor-driven load require more than its running power for a brief period? (a) The AC socket creates extra daylight    (b) The battery’s brand name raises load power    (c) Its start-up surge may exceed steady-state demand    (d) Surge power is identical to a system’s lifetime energy
11. In a simplified calculation, a 24 V DC load drawing 5 A uses approximately ________. (a) 4.8 W    (b) 120 W    (c) 29 W    (d) 240 W
12. Which PPE choice is appropriate to the assessed installation hazards? (a) Ordinary thin cloth gloves as proof of voltage isolation    (b) Bare feet to detect leakage current    (c) Suitable insulated protection, eye protection and appropriate footwear    (d) Loose jewellery to identify electrical contacts
13. Which statement is NOT safe during PV installation? (a) Isolation procedures remain essential    (b) PPE alone makes it safe to touch any exposed live conductor    (c) Eye protection may be required for cutting or drilling    (d) Damaged protective equipment should be replaced
14. After a supervised practice task, the most useful record is ________. (a) Only the final voltage reading without the test conditions    (b) the number of photographs taken without test results    (c) A completion claim without documenting inspection findings    (d) the verified setup, checks performed and any observed faults
15. What is the primary output function shared by AC-supplying PV inverters? (a) Provide appropriately conditioned alternating current    (b) Always create mechanical rotation    (c) Convert all batteries into solar cells    (d) Eliminate all system electrical losses
16. Which plan is most appropriate for selecting an inverter type? (a) Choose the highest output rating without considering configuration or input voltage    (b) Match grid availability, backup expectations, DC supply and load requirements    (c) Ignore operating modes because all inverters are interchangeable    (d) Purchase before identifying any household loads
17. All are reasonable criteria when comparing inverter types except ________. (a) supported system configuration    (b) input and output compatibility    (c) expected load characteristics    (d) the number of photographs on the sales box
18. The primary safety sequence before inverter maintenance is to ________. (a) disconnect random live conductors to see what stops    (b) assume the unit is safe when its display is dark    (c) identify sources, isolate as designed and verify a safe state before work    (d) rely on rubber footwear without testing isolation
19. Which quantity describes nominal DC system voltage? (a) Energy consumed in watt-hours    (b) Electrical potential difference expressed in volts    (c) Appliance operating duration in hours    (d) Length of the PV mounting rail
20. Before handling an isolated inverter, a technician should use ________. (a) appropriate PPE and verify that hazardous energy has been safely isolated    (b) wet hands to improve contact    (c) unprotected jewellery as a conductor test    (d) a metal ladder against exposed live terminals
21. A home requires 1.2 kWh each day. At unchanged daily demand, two days of autonomy require how much delivered energy? (a) 0.6 kWh    (b) 2.4 kWh    (c) 1.2 kWh    (d) 4.8 kWh
22. ________ expresses the energy used by a 100 W load running for 5 hours. (a) 20 W    (b) 500 V    (c) 500 Wh    (d) 5 A
23. Two homes own similar appliances, but one uses them mostly at night. Why can their load profiles differ? (a) Equal appliance counts guarantee equal hourly demand    (b) A profile is only a list of brand names    (c) Time and duration of use change demand distribution    (d) Location has no connection to use patterns
24. Which factor does NOT directly determine daily appliance energy use in Wh? (a) Its electrical power rating    (b) Duration of operation    (c) How many similar appliances run    (d) The font used on its manufacturer’s label
25. A PV system can have energy from modules, batteries and the grid. Why is ‘switching off the inverter’ insufficient by itself? (a) All PV conductors discharge instantly when a display goes dark    (b) Only AC circuits can be hazardous    (c) Batteries contain no stored energy    (d) Other sources may leave parts energised
26. Which of these is NOT acceptable installation practice? (a) Following manufacturer clearances    (b) Working on exposed terminals because the breaker label is unclear    (c) Confirming correct protective ratings    (d) Keeping work areas dry and organised
27. The ________ rating must match the intended battery-system voltage before an inverter is connected. (a) AC output frequency    (b) surge wattage alone    (c) AC output waveform alone    (d) DC input voltage
28. An inverter label shows 1,500 W continuous and 3,000 W surge. Which statement is correct? (a) The inverter supplies 3,000 W continuously without limit    (b) Both figures describe annual energy use    (c) Brief starting demand may be higher than the continuous limit within the specified surge conditions    (d) The 1,500 W value is the device’s input voltage
29. Which assumption would make an autonomy estimate unreliable? (a) Ignoring storage losses and usable-capacity limits    (b) Using actual daily load data    (c) Stating an autonomy target    (d) Allowing a safety margin where justified
30. A load profile is better represented by ________. (a) the inverter’s product photograph    (b) the number of batteries without load information    (c) demand plotted against time rather than a single total alone    (d) the installer’s working hours without appliance use
31. The meaning of ‘days of autonomy’ in an off-grid design is ________. (a) the duration loads can be supplied from storage without expected new generation    (b) the number of days since the panels were installed    (c) how many hours the technician spends on site    (d) the warranty period of a roof clamp
32. Which of the following is NOT the function of a solar inverter? (a) Producing sunlight for the panels    (b) Converting suitable DC to AC    (c) Supporting AC load supply within ratings    (d) Working as part of a coordinated electrical system
33. A house has a 600 W fridge and 350 W of other loads operating simultaneously. Ignoring starting surges, the inverter must continuously support at least ________. (a) 600 W    (b) 950 W    (c) 350 W    (d) 250 W
34. The main reason for checking the type of inverter in a battery-backed design is ________. (a) to assume every grid-only inverter provides backup    (b) to treat an inverter as an unlimited energy source    (c) to avoid calculating the expected AC demand    (d) to ensure its operating mode and DC supply are compatible with storage
35. A learner calls a 1 kW appliance ‘one kilowatt-hour’. Why is this incorrect? (a) Kilowatt is power; kilowatt-hour measures energy over time    (b) Both units express the same quantity    (c) Kilowatt-hour is used only for voltage    (d) Kilowatt always describes battery capacity
36. An appliance draws 250 W for 4 hours daily. Its estimated daily energy demand is ________. (a) 1,000 Wh    (b) 62.5 Wh    (c) 254 Wh    (d) 4,000 Wh
37. A worker identifies a cracked insulated tool. What is the correct action? (a) Wrap it with ordinary paper and proceed    (b) Use it only during bright sunlight    (c) Share it without reporting the damage    (d) Remove it from service and obtain a suitable safe tool
38. An inverter is advertised as ‘1,000 W continuous’. What does the label principally indicate? (a) Its guaranteed energy production each day    (b) The number of PV modules needed without load data    (c) Its rated continuous AC power capability under specified conditions    (d) A fixed running time of 1,000 hours
39. Which statement is NOT a valid system-voltage principle? (a) Components must have compatible electrical ratings    (b) DC and AC sides can have different voltages    (c) Voltage labels must be checked before connection    (d) Any inverter input voltage safely matches every battery voltage
40. Which observation should prompt the trainee to stop an installation exercise? (a) The training manual agreeing with the equipment label    (b) An unexpected live-voltage indication during a supposed isolation test    (c) Correct PPE being available    (d) A supervisor explaining the planned circuit

SECTION B: THEORY (30 Marks)
Instruction: Answer Question 1 and any other TWO questions. Each answered question carries 10 marks. Show your working where applicable.

Question 1 (10 marks). A hostel’s daily loads are a 100 W fan for six hours, a 20 W lamp for five hours, and a 60 W laptop for three hours. (a) Calculate the daily energy use of each and their total, then name the correct unit for the total. (5 marks) (b) Explain FIVE ways a measured load profile improves inverter and storage planning. (5 marks)

Question 2 (10 marks). A clinic uses 1.2 kWh per day. It needs two days of autonomy before allowing for storage losses. (a) Calculate the theoretical delivered energy requirement and explain FOUR reasons actual specified storage may differ. (5 marks) (b) Distinguish system voltage, inverter rating, daily energy demand, days of autonomy and start-up surge. (5 marks)

Question 3 (10 marks). A small shop has 600 W of refrigeration and another 350 W of simultaneous load. The refrigerator may draw extra power briefly on starting. (a) Calculate continuous running demand and state FOUR additional rating checks for inverter selection. (5 marks) (b) Explain FIVE differences or suitability criteria among inverter types and operating modes. (5 marks)

Question 4 (10 marks). During practical training, a learner finds a damaged test lead and an inverter whose display has gone dark. (a) Explain FIVE safe responses before any further work. (5 marks) (b) Describe FIVE pieces of evidence that a supervised practice installation has been completed safely and documented. (5 marks)

Objective Marking Scheme
Question 1 – ✅ (d) performing terminal checks with wet hands
Question 2 – ✅ (a) Required usable storage energy increases approximately threefold
Question 3 – ✅ (b) stop work, keep people clear and follow safe isolation/emergency procedures
Question 4 – ✅ (c) Sum each appliance’s power multiplied by its use duration
Question 5 – ✅ (a) to establish and verify safe isolation using the approved procedure
Question 6 – ✅ (c) 300 Wh
Question 7 – ✅ (a) Permitted DC input voltage and AC output ratings
Question 8 – ✅ (d) An inverter converts power but generation, control and possibly storage remain separate requirements
Question 9 – ✅ (b) its architecture is designed to work with appropriate storage and supported operating modes
Question 10 – ✅ (c) Its start-up surge may exceed steady-state demand
Question 11 – ✅ (b) 120 W
Question 12 – ✅ (c) Suitable insulated protection, eye protection and appropriate footwear
Question 13 – ✅ (b) PPE alone makes it safe to touch any exposed live conductor
Question 14 – ✅ (d) the verified setup, checks performed and any observed faults
Question 15 – ✅ (a) Provide appropriately conditioned alternating current
Question 16 – ✅ (b) Match grid availability, backup expectations, DC supply and load requirements
Question 17 – ✅ (d) the number of photographs on the sales box
Question 18 – ✅ (c) identify sources, isolate as designed and verify a safe state before work
Question 19 – ✅ (b) Electrical potential difference expressed in volts
Question 20 – ✅ (a) appropriate PPE and verify that hazardous energy has been safely isolated
Question 21 – ✅ (b) 2.4 kWh
Question 22 – ✅ (c) 500 Wh
Question 23 – ✅ (c) Time and duration of use change demand distribution
Question 24 – ✅ (d) The font used on its manufacturer’s label
Question 25 – ✅ (d) Other sources may leave parts energised
Question 26 – ✅ (b) Working on exposed terminals because the breaker label is unclear
Question 27 – ✅ (d) DC input voltage
Question 28 – ✅ (c) Brief starting demand may be higher than the continuous limit within the specified surge conditions
Question 29 – ✅ (a) Ignoring storage losses and usable-capacity limits
Question 30 – ✅ (c) demand plotted against time rather than a single total alone
Question 31 – ✅ (a) the duration loads can be supplied from storage without expected new generation
Question 32 – ✅ (a) Producing sunlight for the panels
Question 33 – ✅ (b) 950 W
Question 34 – ✅ (d) to ensure its operating mode and DC supply are compatible with storage
Question 35 – ✅ (a) Kilowatt is power; kilowatt-hour measures energy over time
Question 36 – ✅ (a) 1,000 Wh
Question 37 – ✅ (d) Remove it from service and obtain a suitable safe tool
Question 38 – ✅ (c) Its rated continuous AC power capability under specified conditions
Question 39 – ✅ (d) Any inverter input voltage safely matches every battery voltage
Question 40 – ✅ (b) An unexpected live-voltage indication during a supposed isolation test

Theory Marking Scheme
Question 1 (10 marks)
(a) Fan 600 Wh, lamp 100 Wh, laptop 180 Wh, total 880 Wh, Wh as energy not W, 1 each
(b) Peak, duration, night share, daily demand, growth allowance, energy-saving opportunity, backup design; five 1 each

Question 2 (10 marks)
(a) 2.4 kWh 1, efficiency 1, usable capacity 1, battery condition 1, temperature or future demand 1
(b) Five accurate terms 1 each

Question 3 (10 marks)
(a) 950 W 1, starting surge 1, DC voltage 1, AC voltage/frequency 1, continuous rating or duty conditions 1
(b) Grid access, battery backup, charging, output ratings, supported configurations, protection, cost; five 1 each

Question 4 (10 marks)
(a) Stop, isolate all sources, verify safe state, replace lead, wear suitable PPE, consult instructor; five 1 each
(b) Correct label, secure wiring, protection, ventilation, polarity, test record, supervisor approval; five 1 each