Read Electrical Drawings in a Easiest Way
Bhai agar tu electrician ya electrician se supervisor banna chahta hai toh electrical drawing seekhna zaroori hai. Maine abhi tak jitne bhi projects kiye hain usme sabse pehle drawing study karni padti hai.
Aaj main tujhe electrical drawing reading sikhaaunga – wo bhi itne simple tarike se ki tu kal se hi site pe drawing dekh ke samajh jayega. Ye skill teri interview mein bhi bohot help karegi kyunki Gulf mein har electrician se puchha jaata hai “Can you read drawings?
Agar tu haan bol deta hai lekin actually drawing nahi padh pata toh tu reject ho jayega. Isliye ye post carefully padh aur practice kar.
Table of Contents
Drawing Reading Kyun Itna Important Hai
Simple baat hai. Electrical drawing ek language hai. Jaise tu Urdu ya English padhta hai waise hi drawing padhni aati honi chahiye.
Real Life Scenarios
Scenario 1: Gulf Interview
Interviewer ne tere samne ek SLD (Single Line Diagram) rakhi aur bola “Tell me what is the main incoming supply rating?” Agar tu drawing nahi padh sakta toh tu 2 minute mein reject ho jayega. Simple.
Scenario 2: Site Pe Kaam
Supervisor ne kaha “Panel A se Panel B tak cable lagao.” Bina drawing dekhe tu kaise pata chalega kitne core ki cable chahiye? Kaunsa route follow karna hai? Kis floor pe termination hai?
Scenario 3: Troubleshooting
Circuit trip ho gayi. Drawing nahi padh sakta toh tu randomly wires check karta rahega. Drawing padh leta toh 5 minute mein exact fault point mil jaata.
💡 Real Talk From Experience
NetMagic Data Center ke project mein ek engineer ne mujhse kaha “Arif, ye 3-phase motor ka delta connection drawing mein dikhao.” Maine turant drawing pe U1, V1, W1 aur U2, V2, W2 ke connections mark kar diye. Engineer impressed hua aur next day mujhe senior position offer kiya. Drawing reading = career growth bhai.
Drawing Reading Skills Se Kya Hota Hai
- Interview clear hota hai: Gulf jobs mein 80% candidates drawing test pe hi fail hote hain
- Kaam fast hota hai: Confusion nahi hota, directly point pe jao
- Mistakes kam hoti hain: Galat wire nahi lagega, galat terminal nahi marega
- Respect milti hai: Engineer aur supervisor trust karte hain tujhpe
- Salary zyaada milti hai: Skilled electrician ko QAR 2000-3000 zyaada milta hai
Electrical Drawings Ke Main Types
Electrical field mein tujhe 5-6 main types ki drawings milti hain. Har ek ka apna purpose hai.
|
Drawing Type |
Purpose |
Kab Use Hoti Hai |
|---|---|---|
|
Single Line Diagram (SLD) |
Overall power distribution system dikhati hai |
Main panel design, load calculation, system overview |
|
Schematic Diagram |
Control circuits ka detailed connection |
Motor control panels, PLC wiring, automation |
|
Wiring Diagram |
Physical wire connections point-to-point |
Panel internal wiring, device connections |
|
Layout Drawing |
Equipment placement aur location plan |
Building wiring, conduit routing, fixture positions |
|
Panel Schedule |
Panel mein lage MCBs aur circuits ki list |
Distribution board assembly, labeling |
|
Block Diagram |
System components ka simple flow |
Initial planning, concept presentation |
Kaonsi Drawing Sabse Important Hai
Bhai sab important hain lekin agar tu beginner hai toh SLD aur Panel Schedule pehle seekh le. Ye dono sabse common hain aur interview mein bhi yahi puchha jaata hai.
Common Electrical Symbols – Ye Yaad Kar Le
Drawing mein symbols ka matlab samajhna zaroorat hai. Ye kuch basic symbols hain jo har drawing mein milte hain.
Power Distribution Symbols
|
Symbol Name |
Representation |
Matlab Kya Hai |
|---|---|---|
|
Transformer |
⊏⊐ |
Voltage step up/down karta hai |
|
MCB / Circuit Breaker |
⊓—⊔ |
Protection device – trip hota hai fault pe |
|
Fuse |
—[□]— |
Overcurrent protection – ek baar use |
|
Contactor |
—(K)— |
Electrically operated switch – heavy loads |
|
Motor (3-phase) |
⊚ M |
3-phase induction motor |
|
Earthing |
⏚ |
Ground connection – safety |
Control & Indication Symbols
|
Symbol Name |
Representation |
Use Case |
|---|---|---|
|
Push Button (NO) |
—| |— |
Start button – normally open contact |
|
Push Button (NC) |
—|/|— |
Stop button – normally closed contact |
|
Indicator Lamp |
⊗ |
Status indication – ON/OFF/Fault |
|
Timer |
—[T]— |
Time delay function – star-delta mein use |
|
Overload Relay |
—[OL]— |
Motor overload protection |
📌 Pro Tip – Symbol Chart Bana Le
Maine shuru mein kya kiya tha – ek A4 paper pe saare common symbols likh ke laminate karwa liya aur apne toolbox mein rakha. Jab bhi drawing dekhta tha aur koi symbol nahi samajh aata toh chart dekh leta tha. 3 mahine mein saare symbols yaad ho gaye. Tu bhi ye trick use kar.
Line Types Aur Unka Matlab – Ye Bhi Important Hai
Drawing mein alag alag type ki lines hoti hain. Har line ka matlab alag hai.
|
Line Type |
Appearance |
Meaning |
|---|---|---|
|
Continuous Thick Line |
━━━━━━ |
Main power lines, visible outlines |
|
Continuous Thin Line |
──────── |
Control wiring, dimension lines |
|
Dashed Line |
─ ─ ─ ─ ─ |
Hidden lines, future extensions |
|
Chain Dotted Line |
─·─·─·─·─ |
Center lines, reference lines |
|
Double Line |
══════ |
Bus bars, heavy current paths |
SLD (Single Line Diagram) Kaise Padhte Hain
SLD sabse important drawing hai. Ye poore electrical system ka overview deti hai ek hi line mein.
SLD Mein Kya Dikhta Hai
Ek typical SLD mein ye cheezein hoti hain:
- Incoming supply: Kitne kV/kVA ki supply aa rahi hai
- Main protection: Main MCB/MCCB rating
- Transformer: Agar voltage change ho raha hai
- Distribution panels: Kitne sub-panels hain
- Major loads: AC, motors, lighting panels
- Cable specifications: Kaunsi size ki cable lagani hai
SLD Padhne Ka Step-by-Step Process
Step 1: Top Se Start Karo
SLD hamesha top se neeche padhte hain. Top pe incoming supply hoti hai – jaise 11kV supply ya 415V 3-phase supply.
Step 2: Main Protection Device Dekho
Supply ke turant baad main protection device hota hai. Ye MCCB ya ACB hota hai. Iska rating dekho – jaise 630A MCCB matlab maximum 630 Ampere current handle kar sakta hai.
Step 3: Distribution Path Follow Karo
Main breaker ke baad lines alag alag panels mein jaati hain. Har line pe cable size likha hota hai jaise 4C×95mm² Cu cable. Iska matlab:
- 4C = 4 core cable (3 phase + 1 neutral)
- 95mm² = har core ka cross-section area
- Cu = Copper material
Step 4: Sub-Panels Identify Karo
Har sub-panel ka naam hota hai jaise MDB (Main Distribution Board), MLDB (Main Lighting Distribution Board), ACDB (AC Distribution Board). Inka location bhi likha hota hai like “Ground Floor East Wing”.
Step 5: Load Details Check Karo
Har panel se jo load supply ho raha hai wo bhi SLD mein dikhta hai. Jaise ACDB se 4× 2TR AC units connected hain matlab 4 AC units har ek 2 ton capacity ka.
⚡ Real Example – Hospital SLD
Sidra Hospital ki SLD mein maine dekha:
11kV Incoming → 11kV/415V Transformer (1000kVA) → Main LV Panel 1600A ACB →
Branch 1: Essential Load Panel 400A (Life Safety)
Branch 2: Normal Load Panel 630A (General Lighting)
Branch 3: HVAC Panel 800A (ACs & Ventilation)
Isse clear ho gaya ki hospital mein 3 alag systems hain aur life safety ko priority hai isliye uska dedicated panel hai.
Panel Schedule Kaise Padhte Hain
Panel schedule ek table hota hai jo batata hai ki ek panel ke andar kya kya hai.
Kcmil (kilo-circular mil) Ye European Code Hai Gulf ke Liye Sq MM bolte hai
Panel Schedule Mein Kya Information Hoti Hai
|
Pole No. |
Circuit Description |
MCB Rating |
Cable Size |
Load (kW) |
|---|---|---|---|---|
|
1 |
Lighting – Ground Floor East |
16A Type B |
3C×2.5mm² |
2.5 kW |
|
2 |
Power Sockets – Conference Room |
20A Type B |
3C×4mm² |
3.5 kW |
|
3 |
AC Unit – Office Area |
32A Type C |
3C×6mm² |
5.5 kW |
|
4 |
Water Heater – Pantry |
25A Type B |
3C×4mm² |
4.0 kW |
|
5-6 |
SPARE (Future Use) |
– |
– |
– |
Panel Schedule Se Kya Pata Chalta Hai
1. MCB Position: Pole number batata hai kaunsa MCB kis position pe lagana hai panel mein.
2. Circuit Type: Description se pata chalta hai ye circuit kahan ja rahi hai aur kis load ke liye hai.
3. Protection Rating: MCB rating se pata chalta hai kitna current handle kar sakti hai. Type B/C/D se trip characteristics pata chalti hai.
4. Cable Requirement: Cable size directly purchase list mein ja sakta hai. 3C matlab 3 core (phase, neutral, earth).
5. Load Calculation: Total load add karke transformer ya main breaker size verify kar sakte hain.
Schematic Diagram Basics – Control Circuit
Schematic diagram control circuits ke liye use hota hai. Ye thoda complex hota hai lekin logic samajh gaya toh easy hai.
Schematic Diagram Reading Tips
Tip 1: Power Supply Lines Identify Karo
Usually diagram ke left side pe power supply lines hoti hain – jaise L1, L2, L3 (3-phase) ya L aur N (single phase). Ye vertical lines hoti hain.
Tip 2: Control Circuit Horizontal Padhte Hain
Har horizontal line ek alag circuit hoti hai. Top se bottom padhte jao. Jaise pehli line START circuit hai, doosri STOP circuit, teesri INDICATION circuit.
Tip 3: Contact Designations Samjho
Contacts ko numbers se mark kiya jaata hai jaise K1 (contactor 1), K2 (contactor 2). Agar K1 ka normally open contact kahin use hua hai toh wo K1-NO likhenge ya sirf contact number like 13-14.
Tip 4: Interlocking Dekho
Schematic mein ek circuit doosre circuit ko control kar sakta hai. Jaise K1 ON hone pe K2 OFF ho jaana chahiye (safety interlock). Ye NC contacts se kiya jaata hai.
🔧 Star-Delta Starter Example
Star-delta starter ka schematic samajhne ka simple tarika:
Starting sequence: START button press → Main contactor (KM) ON → Star contactor (KS) ON → Motor starts in star
After timer delay: Timer (T) expires → Star contactor (KS) OFF → Delta contactor (KD) ON → Motor runs in delta
Interlocking: KS aur KD dono ek saath ON nahi ho sakte (NC contacts se prevent kiya jaata hai)
Agar tu star-delta wiring detail mein seekhna chahta hai toh ye post padh.
Drawing Reading Ki Practical Tips – Site Pe Kaam Aayengi
Tip 1: Hamesha Legend Pehle Dekho
Har drawing ke corner mein ek legend box hota hai jo batata hai ki kaun sa symbol kya represent kar raha hai. Pehle ye padh le phir drawing start karo.
Tip 2: Title Block Information Important Hai
Title block mein ye information hoti hai:
- Drawing number (reference ke liye)
- Revision number (latest version check karne ke liye)
- Date (kab banai gayi)
- Approved by (kisi ne verify kiya hai)
- Scale (1:50 ya 1:100 etc)
Kabhi kabhi purani drawing pe kaam kar rahe hote hain aur naya revision aa chuka hota hai. Title block check karo hamesha.
Tip 3: Notes Section Ignore Mat Karo
Drawing ke neeche general notes hote hain jo important information dete hain jaise:
- All cables to be fire rated
- Earthing as per local code
- Conduits to be GI/PVC as specified
- Testing as per IEC standards
Tip 4: Related Drawings Ka Cross-Reference Dekho
Ek drawing reference deti hai doosri drawing ka. Jaise SLD mein likha hoga “Refer DWG No. E-102 for panel details”. Toh E-102 drawing bhi dekhni padegi complete picture ke liye.
Tip 5: Site Conditions Vs Drawing – Difference Ho Sakta Hai
Bhai practical mein kabhi kabhi site pe conditions alag hoti hain. Jaise drawing mein conduit route kuch aur dikhaya hai lekin site pe beam aa gaya toh route change karna padega. Aise cases mein engineer se confirm karo aur as-built drawing update karo.
📱 Mobile Apps For Drawing Reading
Site pe kaam karte waqt ye apps help karti hain:
- AutoCAD Mobile: DWG files khol sakte ho phone pe
- PDF Reader Pro: PDF drawings zoom karke dekh sakte ho
- Electrical Symbols Reference: Symbol yaad nahi toh turant check kar lo
- Unit Converter: mm to inches, kW to HP etc quick conversion
Common Mistakes Jo Beginners Karte Hain
Mistake 1: Symbols Confuse Ho Jana
Problem: Contactor aur relay ka symbol similar lagta hai. Motor aur generator ka bhi.
Solution: Symbol chart bana ke rakh. Shuru mein time lagta hai but gradually yaad ho jaate hain. Context se bhi samajh aa jaata hai – jaise power circuit mein motor hoga, control circuit mein relay.
Mistake 2: Cable Size Galat Padhna
Problem: 4C×25mm² ko 4×25mm cable samajh liya. Difference hai bhai – pehla 4 core cable hai, doosra 4 separate single core cables.
Solution:
- 4C×25mm² = 4 core cable (ek sheath ke andar 4 wires)
- 4×25mm² = 4 alag alag single core cables
- 3C+E = 3 core + separate earth
Mistake 3: Scale Ignore Karna
Problem: Drawing pe distance measure karke site pe jaake pata chala scale 1:100 tha toh actual distance 100 times zyaada hai.
Solution: Hamesha scale dekho. Agar drawing pe 10cm distance hai aur scale 1:100 hai toh actual distance = 10cm × 100 = 1000cm = 10 meters.
Mistake 4: Revision Check Nahi Karna
Problem: Purane revision pe kaam kar liya aur baad mein pata chala ki design change ho gaya tha.
Solution: Hamesha latest revision number confirm karo. Title block mein REV A, REV B etc likha hota hai. Site pe kaam shuru karne se pehle engineer se confirm kar lo latest drawing kon si hai.
Mistake 5: Notes Padhna Bhool Jana
Problem: Drawing dekh ke seedha kaam shuru kar diya. Baad mein notes mein likha tha “All outdoor cables to be armored” but normal PVC cable laga di.
Solution: Drawing ke general notes aur specific notes dono carefully padho. Specification sheet bhi refer karo.
FAQ – Quick Answers Tere Doubts Ke?
Q: Drawing reading seekhne mein kitna time lagta hai?
A: Basic symbols aur SLD reading 2-3 weeks mein aa jaati hai agar tu daily 30 minutes practice kare. Complex schematic diagrams 2-3 months mein comfortable ho jaate hain. Lekin real mastery 1-2 saal mein aati hai jab tu different types ki drawings dekhta hai site pe.
Q: Kya drawing reading ke liye AutoCAD seekhna zaroori hai?
A: Nahi bhai. AutoCAD drawing banane ke liye seekhte hain. Tujhe sirf drawing padhni hai toh PDF viewer ya AutoCAD viewer app enough hai. Drawing software operation electricians ke liye optional hai – draftsmen ka kaam hai wo.
Q: Gulf interview mein drawing test kaise hota hai?
A: Usually interviewer ek SLD ya panel schedule dikhata hai aur 4-5 questions puchta hai jaise: “What is the main breaker rating?”, “Which ccable size is used for AC circuit?”, “How many distribution panels are there?”. Simple questions hote hain agar tu drawing padh sakta hai. Gulf interview questions ki complete guide yahan dekh.
Q: Agar koi symbol samajh nahi aaya toh kya karun?
A: Pehle drawing ke legend section check karo – usually wahan explanation hota hai. Agar wahan bhi nahi hai toh engineer ya supervisor se puch lo. Kabhi assume mat karo – galat assumption = costly mistake. Symbol reference apps bhi use kar sakta hai phone pe.
Q: Layout drawing aur SLD mein kya farak hai?
A: SLD electrical connection dikhata hai (power flow aur protection). Layout drawing physical location dikhata hai (kahan switch lagana hai, kahan socket lagana hai, conduit kis route se jayega). Dono saath mein dekhte hain – SLD se system samajho, layout se installation karo.
Q: Drawing pe dimensions inches mein hain lekin site pe metric scale use hota hai. Convert kaise karun?
A: 1 inch = 25.4 mm yaad rakh. Quick conversion: inches ko 25 se multiply kar de approximate aa jayega. Example: 10 inches ≈ 10×25 = 250mm. Accurate chahiye toh calculator use kar. Phone pe unit converter app rakh site pe kaam ke liye.
Q: Kya drawing reading practice ke liye free resources hain online?
A: Haan bhai. YouTube pe “electrical drawing reading tutorial” search kar. Manufacturer websites pe sample drawings milti hain jaise Schneider, ABB, Siemens. PDF download karke practice kar sakta hai. VoltGuru pe bhi aur posts aane wali hain drawing examples ke saath.
Q: Drawing reading mein sabse common galti kya hoti hai beginners ki?
A: Symbol confusion sabse zyaada hoti hai. Contactor ko relay samajh liya ya NC contact ko NO samajh liya. Second common mistake hai scale ignore karna – drawing pe 5cm distance hai but actual 5 meters hai kyunki scale 1:100 tha. Third mistake revision check nahi karna – purani drawing pe kaam kar rahe hote hain.
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