Electrical Calculator — No. 09

Electrical Load
Calculator

Apne saare loads add karo — total kVA, kW, current aur recommended incomer size milega. IEC 60364 ke hisaab se diversity factor ke saath.

Calculator

Load Name kW PF Qty

System Settings

Supply System

Voltage (V)

Diversity Factor

Future Growth %

Result — Total Load Summary

— kVA

Total kW

—kW

With diversity

Full Load Current

—A

Incomer FLC

Design Current

—A

With growth factor

Recommended Incomer

—

MCCB rating

Transformer Size

—

Min kVA rating

Generator Size

—

At 0.8 PF rating

Load Breakdown

Theory + Site Knowledge

Electrical Load Calculation Kya Hoti Hai?

Bhai, Gulf ki kisi bhi site pe DBs design karo, transformer size karo, ya generator select karo — sab me load calculation pehla step hai. Qatar University ke campus expansion me maine khud 40+ DBs ke liye load calculations ki thi. Galat calculation matlab ya toh oversized equipment (paisa waste) ya undersized (fire risk).

Load calculation me 4 steps hote hain: har load ki kW/kVA find karo, diversity factor lagao, future growth add karo, phir incomer/transformer/generator size determine karo.

Connected Load vs Demand Load

Connected load matlab saare loads ki total peak capacity — jaise agar 10 AC units hain, sabki nameplate kW add karo. Lekin practically sab ek saath full load pe nahi chalte. Isiliye diversity factor lagaate hain — real demand estimate karne ke liye.

Demand Load (kW) = Connected Load × Diversity Factor
Design kVA = Demand Load / Average PF
Current (3-ph) = kVA × 1000 / (√3 × V)
Current (1-ph) = kVA × 1000 / V
Design Current = FLC × Growth Factor

Diversity Factor — Gulf Sites Pe

Building Type	Diversity Factor	Reason
Residential Villa	0.75 – 0.80	Sab rooms ek saath nahi
Office Building	0.70 – 0.80	Staggered occupancy
Hotel / Hospital	0.65 – 0.75	24hr operation, managed load
Industrial Plant	0.60 – 0.70	Shift-based operation
Small Shop	0.85 – 0.95	Limited loads, all used

Future Growth Factor

Gulf ki sites pe minimum 20–25% growth factor rakhna chahiye. Qatar aur UAE me building expansions aur load additions bahut common hain. Sidra Hospital me humne 25% growth factor rakha tha — aur 2 saal me woh 18% use ho gaya tha.

Qatar University — Real Example

Block: Academic building, 3-phase 415V

Loads: AC (42kW) + Lighting (8kW) + Sockets (15kW) + Lab equipment (20kW)

DF 0.70: 85kW × 0.70 = 59.5kW | kVA = 70.0

Growth 25%: Design = 87.5 kVA → 100 kVA transformer selected

Transformer ka 80% se zyada load mat rakho continuously — Gulf ke ambient temperature me overheating risk hota hai. 100 kVA transformer pe max continuous load 80 kVA rakho.

Incomer MCCB Sizing

Design Current	MCCB Rating	Note
Up to 40A	63A	Standard size
41 – 63A	100A	Next standard
64 – 80A	125A
81 – 100A	160A
101 – 125A	200A
126 – 160A	250A
161 – 200A	315A
201 – 250A	400A

Related Calculators:
kW to Amp | Cable Size | Voltage Drop | Motor Starting Current

Frequently Asked Questions

Diversity factor Gulf sites pe kitna rakhna chahiye? +

Gulf ki residential aur commercial sites pe 0.70–0.80 standard practice hai. IEC 60364-4-41 me minimum values given hain. Hospital aur data centers ke liye 0.85–0.90 rakho kyunki wahan loads zyada predictable hote hain.

Motor load ka PF aur lighting ka PF alag kyun hota hai? +

Induction motors lagging reactive power consume karte hain — PF 0.75–0.85 typical. LED lighting me PF correction capacitor hoti hai — 0.90–0.95 milta hai. Resistive loads (heaters, incandescent) ka PF = 1.0. Mixed load ka average PF 0.80–0.85 estimate karo agar exact pata nahi.

Transformer ka size load se bada kyun hona chahiye? +

Transformer continuously 80% se zyada load pe nahi chalana chahiye — especially Gulf me jahan ambient 40–50C hoti hai. 100% pe continuous operation se transformer overheats, insulation damage hoti hai aur life kam hoti hai. Design load × 1.25 = minimum transformer kVA.

Generator size transformer se bada kyun hota hai? +

Generator ratings 0.8 PF pe hoti hain — matlab 100 kVA generator = 80 kW real power deta hai. Plus, motor starting surge current ke liye generator ko derating factor lagana padta hai. Generally generator = transformer size × 1.25 minimum rakho.

Single phase aur 3 phase load calculation me kya farak hai? +

3-phase me current formula me √3 (1.732) aata hai — isliye same kVA pe current kam hoti hai. 10 kVA 3-phase = 13.9A at 415V. 10 kVA 1-phase = 43.5A at 230V. Isiliye bade loads ke liye hamesha 3-phase prefer karo — cables, MCBs sab chhote size ke lagte hain.

VoltGuru.in — Electrical Knowledge for Gulf Professionals / IEC 60364-4 / Load Calculation Standard

Electrical LoadCalculator