Punjab PSEB Matric NSQF Automotive (EV Service Assistant) cheat sheet

India's EV ecosystem has four pillars: vehicle OEMs, battery/component suppliers, charging infrastructure providers, and service/skilling bodies such as ASDC and NSDC.

NSQF levels run 1-10; the PSEB Matric NSQF automotive trades sit at Level 4, combining Class 10 general education with job-specific competencies.

BEV = battery only; HEV = engine plus battery, no external charging; PHEV = engine plus battery with grid charging; FCEV = hydrogen fuel cell generating electricity on board.

EV drivetrain removes clutch, gearbox, exhaust, fuel tank and ignition system; retains motor, controller, reducer/gearbox, battery pack and BMS.

FAME/PM E-DRIVE style schemes subsidise electric two-, three- and four-wheelers and public charging; state EV policies add road-tax and registration waivers.

Automotive service roles follow a ladder: helper/apprentice, EV service assistant, technician, senior technician, supervisor, workshop manager.

Key regulators and standards: AIS-038 (EV safety), AIS-156 (battery safety), CMVR, BIS IS 17017 for charging connectors, CEA safety regulations for charging stations.

Ohm's law: V = I × R; power P = V × I = I²R = V²/R. A 48 V pack drawing 20 A delivers 960 W.

Series connection adds voltage (same current); parallel connection adds capacity/current (same voltage). Two 12 V 100 Ah batteries in series give 24 V 100 Ah.

Voltage is potential difference (volt), current is flow rate (ampere), resistance opposes flow (ohm); energy in Wh = V × Ah, and 1 kWh = 1000 Wh.

DC flows one way (battery, solar); AC reverses periodically (grid, mains). An inverter converts DC to AC; a rectifier/charger converts AC to DC.

Continuity test uses a multimeter in resistance/buzzer mode on a de-energised circuit; a near-zero ohm reading with beep indicates a closed path.

Insulation resistance is measured with a megohmmeter at a specified test voltage; low readings indicate leakage risk and the circuit must be isolated.

CAN bus is a two-wire differential serial network (CAN-H, CAN-L) allowing the BMS, motor controller and dashboard to exchange data; termination resistors are typically 120 ohm.

Lithium-ion cell nominal voltages: LFP about 3.2 V, NMC about 3.6-3.7 V, LTO about 2.3-2.4 V; full charge is roughly 3.65 V (LFP) and 4.2 V (NMC).

Pack configuration: 13S LFP ≈ 48 V nominal; 16S LFP ≈ 51.2 V; 20S NMC ≈ 72 V. Capacity in Ah stays the same in series, energy in Wh = pack voltage × Ah.

BMS functions: cell voltage monitoring, temperature sensing, cell balancing, state of charge (SoC) and state of health (SoH) estimation, over-charge/over-discharge and over-current protection, and CAN reporting.

Passive balancing bleeds energy from high cells through resistors; active balancing transfers charge between cells. Both aim to equalise cell voltages.

SoC is remaining charge as a percentage; SoH compares current capacity to rated capacity and indicates ageing.

Never charge a lithium pack below 0 °C - lithium plating risk; store at 30-50% SoC in a cool dry place; a swollen, leaking or hot pack is removed from service.

Deep discharge below the cut-off voltage damages cells; a BMS in protection mode may show zero output until the pack is safely recovered by a qualified person.

BLDC/PMSM motors are the norm in Indian EVs; the controller commutates phases electronically using Hall sensor or sensorless feedback.

Three phase cables are conventionally colour-coded U, V, W (often yellow, green, blue); swapping any two reverses rotation direction in a brushless motor.

Motor controller converts battery DC into variable-frequency three-phase AC; it limits current and protects against over-temperature, over-voltage and throttle faults.

Hall sensor faults cause jerking, failure to start or wrong direction; a faulty sensor is checked with a multimeter on the 5 V signal line while rotating the wheel by hand.

Throttle (0.8-4.2 V typical) and brake-cut signals feed the controller; a brake switch stuck closed prevents motor operation.

A reducer or single-speed gearbox transfers motor torque to the wheel; no clutch or multi-speed gearbox exists in most two- and three-wheeler EVs.

Regenerative braking uses the motor as a generator to recover energy; it only works above a minimum speed and when the battery can accept charge.

AC charging uses the vehicle's on-board charger; DC fast charging bypasses it and feeds the pack directly through the charging port.

India's common AC connector for light EVs is the 3-pin/15 A domestic plug or Type 2; DC fast charging uses CCS2 or the Bharat DC-001 (GB/T style) connector.

Charging modes: Mode 1 (direct socket, no protection), Mode 2 (in-cable control box), Mode 3 (dedicated EVSE with communication), Mode 4 (DC fast charger).

Bharat AC-001 uses a 3-pin connector up to about 3.3 kW; Bharat DC-001 is 48-72 V, up to 15 kW, typical for small electric cars and three-wheelers.

Charging time ≈ battery capacity (kWh) ÷ charger power (kW) × efficiency factor; a 3 kWh pack on a 1 kW charger needs about 3 hours plus losses.

Before connecting, inspect the plug, cable and port for damage, moisture or burn marks; connect the vehicle end first, then the supply, and stop charging before disconnecting.

Never charge from a loose or unearthed socket, never use a damaged cable, and never pull the connector under load - arcing damages pins and poses a shock hazard.

Diagnosis order: confirm customer complaint, check for fault codes on the dashboard or diagnostic tool, inspect visually, then test electrically - never guess-replace parts.

High-voltage isolation is the first step for any pack, motor or controller work: switch off, remove service plug/contactor, wait the manufacturer-specified time (often 5-10 minutes) and verify zero volts.

Common no-start causes: low 12 V auxiliary battery, brake-cut switch stuck, side-stand switch engaged, throttle fault, blown fuse, BMS in protection.

Reduced range causes: low tyre pressure, dragging brakes, ageing pack (low SoH), cold temperature, aggressive riding, faulty charger leaving pack partly charged.

Preventive maintenance schedule: tyre pressure and brake adjustment weekly; fastener torque and cable inspection monthly; battery capacity/SoH check and coolant check at specified intervals.

Motor overheating or controller cut-out after load usually indicates over-current, blocked cooling, wrong phase wiring or a failing Hall sensor - check temperature and phase resistance.

Record every fault code, measurement and replaced part in the job card so warranty claims and repeat repairs are traceable.

Thresholds: DC above 60 V and AC above 30 V are treated as high voltage; EV traction packs of 48-72 V and above fall in this zone.

PPE for HV work: Class 0 (1000 V) insulating gloves tested every 6 months, leather over-gloves, arc-rated clothing, face shield, insulated tools and rubber mat.

Work rule: one hand in pocket where possible, remove metal jewellery and watches, never work alone on HV systems, and use a lockout/tagout procedure.

Electric shock response: do not touch the casualty until the supply is isolated; call emergency services, then give CPR or first aid if trained.

Battery fire response: use large amounts of water or a Class D/ABC extinguisher as per manufacturer guidance; lithium fires can reignite hours later, so isolate and monitor.

Electrolyte contact: flush skin or eyes with clean water for at least 15 minutes and seek medical help; do not induce vomiting if swallowed.

Damaged or swollen packs are quarantined outdoors away from combustible material, labelled, and handed to an authorised recycler - never opened or punctured.

Torque wrench use: set to specified value, tighten smoothly to the click, never use it to loosen fasteners, and recalibrate periodically.

Insulated hand tools marked 1000 V are mandatory for HV work; ordinary spanners must not be used near live terminals.

Job card contents: customer details, vehicle registration and VIN, odometer, complaint, diagnosis, parts replaced, labour, technician signature and customer sign-off.

Vehicle identification: VIN is a 17-character code; the chassis number and motor number are recorded on the job card for warranty claims.

5S workplace discipline: sort, set in order, shine, standardise, sustain - keeps tools traceable and reduces accidents.

Customer interaction: listen fully, restate the complaint, explain the fault and cost in simple language, give a delivery time, and never promise beyond what the workshop can deliver.

Warranty rules: battery and motor warranties are voided by unauthorised opening, water ingress, tampering or use of non-approved chargers; record evidence before repair.

Communication cycle: sender, message, channel, receiver, feedback; active listening means not interrupting and confirming understanding.

Resume essentials: contact details, objective, education and NSQF qualification, technical skills, work experience or apprenticeship, references.

Interview basics: research the employer, dress neatly, arrive early, answer with specific examples (situation, action, result), and ask one relevant question.

Entrepreneurship: identify a local need (EV service, charging point, battery swapping), estimate capital and running cost, price services to cover cost plus margin, and maintain basic books.

Statutory registrations for a small workshop: GST, Udyam/MSME registration, shop and establishment licence, and a current account for payments.

Environmental impact: EVs cut tailpipe emissions and noise but shift burden to battery manufacturing and disposal; proper recycling of lithium packs and lead-acid auxiliary batteries is mandatory.

E-waste and battery rules in India place take-back responsibility on producers; workshops must return used packs to authorised recyclers, never to informal scrap dealers.