PURPOSE OF THIS DOCUMENT This document defines the mandatory workmanship standards, technical practices, installation methodologies, safety requirements, and quality expectations to be followed by all outsourced labour teams, subcontractors, and installation partners executing rooftop solar projects for Zolar Roof Pvt Ltd. These standards are intended to ensure: Long-term system reliability Electrical and structural safety High-quality workmanship Utility compliance Proper commissioning approval Reduced service complaints Enhanced system life and performance Any deviation from these standards without prior approval may result in: Rework at contractor’s cost Rejection of work Payment hold/reduction Blacklisting from future projects 1. GENERAL INSTALLATION STANDARDS 1.1 Professional Workmanship All installation works shall be executed in a professional and technically sound manner. The installation team shall ensure: Proper finishing Clean routing Accurate alignment Neat cable dressing Secure fastening Safe working practices Temporary or makeshift workmanship is strictly prohibited. 1.2 Mandatory Site Cleanliness The contractor shall: Maintain site cleanliness during work Remove scrap materials daily Avoid leaving sharp metal pieces or cable waste on rooftops Hand over the site in clean condition after completion 2. SOLAR MODULE HANDLING STANDARDS 2.1 Solar Panel Handling Precautions Solar modules shall always be handled carefully by holding the aluminium frame. The following are strictly prohibited: Climbing on solar panels Sitting on solar panels Stepping on the front glass surface Applying body weight on panel edges or corners Improper handling may cause: Micro-cracks in solar cells Snail trails Hotspots Power degradation Warranty rejection by manufacturers Any module damage caused due to mishandling shall be the sole responsibility of the contractor. 3. ELECTRICAL INSTALLATION STANDARDS 3.1 Alignment & Mounting Standards Spirit levels / water levels shall be checked for: Inverters ACDBs DCDBs Meter boxes Cable conduits Cable trunks All equipment shall be mounted level and aligned properly. 3.2 Cable Termination Standards All cable terminations shall be done using: Copper lugs Press sleeves Proper crimping tools Loose wire insertion is prohibited. Heat shrink sleeves shall be used wherever necessary to ensure: Proper insulation Moisture protection Professional finishing 3.3 Cable Routing Standards Cable trays, conduits, trunks, or HD flexible pipes shall be used for all cable routing. Loose hanging cables are not acceptable. AC and DC cables shall be routed separately wherever possible. Saddle spacing between conduit saddles shall not exceed 60 cm. Lightning Arrestor cable holder spacing shall not exceed 50 cm. 3.4 Colour Coding Standards Proper colour coding shall be followed in all electrical wiring works according to standard electrical practices. Incorrect colour coding is unacceptable. 3.5 Neutral-Earth Voltage Standard The neutral-to-earth voltage shall be maintained below 3V. Work may be rejected if it exceeds 5V. Loose neutral connections and improper grounding are common causes of high NE voltage and must be rectified before commissioning. 3.6 Lightning Arrestor Down Conductor Standards The 8 mm lightning arrestor down conductor shall be routed professionally. Sharp bends, unnecessary loops, twists, and curves shall be avoided. The conductor path shall be as straight and short as possible. 3.7 Existing Meter Box Rearrangement If required, the existing meter box arrangement shall be modified professionally for: Neutral link addition Proper meter accessibility Utility compliance 4. EARTHING & LIGHTNING PROTECTION STANDARDS 4.1 Mandatory Earthing Requirement A minimum of three independent earthing systems is mandatory: AC Side — AC Equipment Earthing DC Side — DC Equipment Earthing Lightning Arrestor — LA Earthing 4.2 Earth Electrode Standards Copper-bonded earth rods of minimum 5 ft length shall be used. Earth electrodes shall preferably be installed vertically. 4.3 Earthing Pit Location Standards Earthing pits shall preferably be installed at least 3 feet away from the building foundation. Minor modifications are permitted depending on site conditions. Minimum spacing between earthing pits shall be D ≥ 2L, where D is the distance between pits and L is the length of the earth electrode. 4.4 Earthing Pit Construction Procedure For each earthing point: Dig a main pit approximately equal to the size of the earth chamber. Dig an additional narrow hole of approximately 2 feet depth. Insert the earth electrode by pressing downward. Hammering should be avoided wherever possible. Earth enhancement compound shall be mixed with excavated soil. Backfilling shall be properly compacted. 4.5 Earthing Interconnection Standards All earthing systems (AC, DC, LA, and existing building earth if available) shall be interconnected. Bare copper conductor shall be used for interconnection. Minimum burial depth for interconnection conductor: 1 foot minimum depth. Interconnection improves: Earth resistance values Fault current dissipation Lightning protection effectiveness Step potential reduction 4.6 Earth Chamber Standards Earth chambers shall remain accessible after installation. Chamber cover shall be at finished ground level. Provision for future water filling and testing shall be maintained. 4.7 Earth Resistance Standards The earth resistance value of each earthing pit shall be less than 4 Ohms. Work shall be rejected if any earthing point exceeds 5 Ohms. Earth resistance testing is mandatory before commissioning. 5. INVERTER, DB & METER INSTALLATION STANDARDS 5.1 Preferred Equipment Arrangement Preferred installation sequence: DCDB Inverter ACDB Energy Meter Box Minor modifications are permitted based on actual site conditions. 5.2 Inverter Ventilation Standards Mandatory clearance requirements: Top Side — 50 cm Left Side — 30 cm Right Side — 30 cm Insufficient ventilation may cause: Overheating Power derating Frequent tripping Reduced inverter lifespan Warranty voidance 5.3 Equipment Location Selection Priority Priority 1 — Minimize Overall Wiring Length Priority 2 — Minimize DC Cable Length Priority 3 — Minimize AC Cable Length Priority 4 — Minimize Earthing Conductor Length 5.4 Meter Box Placement Standards Energy meter box shall preferably be installed near the existing utility meter. Future net meter installation space shall be considered. Meter location shall be accessible to utility staff, visible at eye level wherever possible, and remain obstruction free. 5.5 Neutral Link Standards Neutral link provision is mandatory in most utility approval cases. The contractor shall ensure tight neutral terminations, proper link arrangement, and secure fastening. Loose neutral connections are a major cause of field failures. 5.6 Grid Connection Standards The inverter generation line shall be connected to the neutral link and outgoing side of cut-off fuse / isolator. All terminations shall be properly crimped, ferruled, tightened, and insulated. 6. STRUCTURAL INSTALLATION STANDARDS 6.1 Walkway & Handrail Requirement For sheet roof installations: Walkways are mandatory. Handrails shall be provided wherever required for safety and future maintenance. Simple, sturdy, and maintenance-friendly designs shall be adopted. 6.2 Painting Standards Before installation, one coat of primer and one coat of paint shall be applied on structural members. After welding, flux shall be properly cleaned/chiselled and additional primer and paint coating shall be applied. 6.3 Welding Standards All welding works shall be clean, uniform, strong, and professionally finished. Poor-quality welding will not be accepted. 6.4 Structural Height & Tilt Standards Minimum northern side structure height: 1.6 m minimum. Recommended structure tilt angle: 12°–16°. 6.5 Pipe Joint Welding Standards All four sides of pipe joints shall be welded uniformly. Flux shall be removed completely. Repainting after welding is mandatory. 6.6 Purlin & Rafter Welding Standards Purlins shall be welded to rafters on both sides. Welding thickness shall remain consistent. Flux cleaning and repainting are mandatory. 6.7 Waterproofing Standards Professional waterproofing is mandatory for all roof penetrations. For sheet roofs, proper tar sheet or approved sealing methods shall be used. For concrete roofs, proper waterproofing shall be done around concrete footings and anchor points. Water leakage complaints due to improper workmanship shall be rectified by the contractor at their own cost. 7. SAFETY REQUIREMENTS Mandatory PPE: Safety helmet Safety shoes Gloves Safety belt for height work Unsafe practices are strictly prohibited. Electrical isolation shall be ensured before termination work. Work during heavy rain, thunderstorms, or unsafe roof conditions shall be avoided. 8. TESTING & COMMISSIONING REQUIREMENTS Before project handover, the contractor shall ensure: Proper polarity testing Earthing continuity testing Earth resistance measurement AC/DC voltage verification Inverter commissioning Monitoring setup verification Utility compliance verification Proper generation verification 9. FINAL QUALITY RESPONSIBILITY The outsourced contractor remains fully responsible for: Structural quality Electrical workmanship Waterproofing integrity Proper cable routing Safety compliance System reliability Any defect arising due to poor workmanship during inspection, commissioning, utility approval, customer handover, or warranty period shall be rectified by the contractor without additional charges.