WAPDA DDS-84 & IEC 60076 Certified Heavy Power Substation

7000 kVA Transformer in Pakistan (7 MVA) — Price, Specs & Turnkey Supply

Q: What is the full load secondary current of a 7000 kVA (7 MVA) transformer?

At standard 415V three-phase line-to-line, a 7000 kVA (7 MVA) transformer produces 9,738.4 Amperes of low-voltage (LV) full load current: 7,000,000 / (1.732 × 415) = 9,738.4 A. On the 11 kV primary high-voltage side, the rated full load current is 367.4 Amperes.

Q: What secondary connection is required for 9,738A LV current?

Handling nearly 10,000 Amperes with conventional cables causes severe space and thermal congestion (requiring 16-20 runs of 300mm² cable per phase). Therefore, modern engineering practices mandate a sandwich Copper Busbar Trunking (BBT) system rated at 10,000A, or dividing the secondary into dual incomer panels each protected by a 5000A Air Circuit Breaker (ACB).

Q: What are the civil foundation and oil containment requirements for a 7 MVA transformer?

A 7000 kVA transformer weighs approximately 21,500 kg (21.5 metric tons). It requires a heavy reinforced concrete foundation pad (minimum 4000 psi concrete) measuring at least 5,200 mm × 3,600 mm × 600 mm deep, surrounded by an oil-soak gravel pit capable of containing 100% of the 7,500 liters of oil, enclosed by 2.4-meter perimeter security fencing.

Q: What size PFI capacitor bank is required for a 7000 kVA substation?

A 2,100 kVAR to 2,600 kVAR automatic Power Factor Improvement (PFI) system divided into 16 to 24 microprocessor-controlled capacitor stages with 7% or 14% detuned harmonic reactors is required to maintain plant power factor above 0.95 under heavy inductive motor and furnace loads.

The 7000 kVA (7 MVA) power transformer is an ultra-heavy industrial powerhouse engineered for 10-ton to 12-ton steel induction melting furnaces, chlor-alkali electrolysis complexes, mega cement grinding plants, and dedicated 132/11kV grid substation step-down substations in Pakistan. Delivering a massive 9,738.4 Amperes of low-voltage secondary current at 415V three-phase, this unit delivers uncompromised dynamic mechanical bracing against severe cyclic short-circuit forces, low core losses, and superior forced-oil/forced-air (ONAF/OFWF) thermal stamina.

Rated Capacity 7000 kVA (7 MVA)

LV Output (415V) 9,738.4 A

Primary Voltage 11 / 33 kV

Stock Status Available New/Recon

Request Official Quotation → Engineering Specs ↓ 0300 6919113

7000 kVA Substation Blueprint DWG: TL-PWR-7000

✓ 99.99% Prime Electrolytic Copper Windings (or Aluminum option)

✓ Laser-Scribed Prime CRGO Core Steel (Low Hysteresis Loss)

✓ High Dielectric Breakdown Mineral Oil (BDV > 50kV)

✓ Off-Circuit Tap Changer (OCTC: ±2.5%, ±5%) or Motorized OLTC

✓ Complete Routine & Type Test Reports from Accredited Lab

Ready for Dispatch / Manufacturing Feeder Mobilization: 24h

Commercial Transparency

7000 kVA Transformer Price in Pakistan (7 MVA Power Substation) — Key Cost Factors

Commercial pricing for a 7000 kVA (7 MVA Power Substation) transformer in Pakistan is dictated by raw engineering commodities and technical configurations rather than an arbitrary sticker price. Here is how your commercial proposal is structured:

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Winding Conductor Purity

Prime 99.99% Electrolytic Copper provides maximum conductivity, lower I²R losses, and longer service life (25-30 years). EC Grade Aluminium windings provide a lower initial cost option for budget-sensitive seasonal agricultural projects.

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Dielectric Oil vs. Dry-Type

Standard mineral oil-immersed (ONAN) with 7,500 Liters of Class-I inhibited oil is optimal for outdoor substations. Cast resin dry-type (AN/AF) is required for indoor commercial basements where fire regulations strictly prohibit oil.

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Tap Changer Mechanism

Standard units include a 5-position Off-Circuit Tap Changer (OCTC: ±2.5%, ±5%) for seasonal grid adjustment. On-Load Tap Changers (OLTC) with automatic voltage regulating relays are available for sensitive manufacturing loads.

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Brand New vs. Certified Reconditioned

Brand-new units carry 18 months comprehensive replacement warranty. Certified reconditioned units undergo vacuum baking, new sealing gaskets, fresh oil filtration, and high-voltage testing with 12 months warranty at 40-50% savings.

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Protection & Instrumentation

Heavy units include dual-float Buchholz relay, Magnetic Oil Level Gauge (MOG), dial-type Oil & Winding Temperature Indicators (OTI/WTI) with alarm/trip contacts, and spring-loaded pressure relief devices (PRD).

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Turnkey Substation EPC

TransfoLine offers turnkey delivery including civil foundation plinth casting, HT drop-out fuse/VCB switchgear, LT breaker panel, dual earthing pits (<1 Ohm), and complete DISCO testing/energization approval.

Commercial Pricing Structure for 7000 kVA (7 MVA Power Substation)

A 7000 kVA (7 MVA) power transformer represents a major capital infrastructure asset in Pakistan. Commercial pricing is dictated by over 5,800 kg of pure 99.99% electrolytic copper conductor, 7,400 kg of prime cold-rolled grain-oriented (CRGO) silicon steel core laminations, 7,500 liters of Class-I dielectric oil, motorized On-Load Tap Changer (OLTC) mechanism, and accredited high-voltage laboratory testing under WAPDA DDS-84 and IEC 60076. TransfoLine supplies brand-new 7 MVA units (18-month warranty) and certified reconditioned 7 MVA units (12-month warranty) delivering 40% to 50% capital savings with immediate inspection availability.

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Technical Datasheet

Engineering Specifications — 7000 kVA (7 MVA Power Substation)

Standard engineering parameters conforming to WAPDA Specification DDS-84 and International Electrotechnical Commission (IEC 60076):

Electrical & Mechanical Parameter	Design Rating & Value	Engineering Notes & Standards
Nominal Apparent Power Rating	7000 kVA (7 MVA Power Substation)	Continuous maximum rating under 50°C ambient Pakistan summer conditions
Active Real Power Capacity	5,600 kW (at 0.8 PF)	Effective usable plant load based on standard 0.8 lagging power factor
Primary High Voltage (HV)	11,000 Volts (11 kV) / 33,000 Volts (33 kV)	Standard 3-phase, 50 Hz utility feeder supply across all DISCO territories
Secondary Low Voltage (LV)	415 Volts Line-to-Line / 240 Volts Line-to-Neutral	3-phase, 4-wire with neutral brought out to external terminal bushing
Full Load Secondary (LV) Current	9,738.4 A	Calculated: kVA / (√3 × 0.415 kV) at rated full load
Full Load Primary (HV) Current	367.4 A	Calculated: kVA / (√3 × 11.0 kV) at rated primary voltage
Vector Group Connection	Dyn11 (Delta High Voltage / Star Neutral Low Voltage)	Standard 30° phase angle displacement per WAPDA / IEC specifications
Cooling Class & Medium	ONAN (Oil Natural Air Natural) / ONAF Forced Air Option	Pressed steel radiator fin banks ensuring <50°C top oil temperature rise
Percentage Impedance (%Z)	7.5% - 8.0%	Guaranteed tolerance ±10% per IEC 60076 short-circuit limitation
No-Load (Core) Losses	7,200 Watts	High-permeability cold-rolled grain-oriented (CRGO) silicon core steel
Full-Load (Copper) Losses	54,000 Watts	Measured at rated current at 75°C reference temperature
Transformer Mineral Oil Volume	7,500 Liters	Uninhibited Class-I mineral oil (BDV > 50 kV fresh)
Total Weight (with Oil & Fittings)	21,500 kg (21.5 Tons)	Active copper winding weight: 5,800 kg
Overall Physical Dimensions	4,200 mm (L) × 2,750 mm (W) × 3,650 mm (H)	Overall clearance footprint including radiators and conservator
Recommended HT Switchgear / Breaker	11kV/33kV 1250A Vacuum Circuit Breaker (VCB) with Numerical Differential Relay (87T)	11kV/33kV incoming breaker with numerical differential (87T) and IDMT relays
Recommended LT Main Circuit Breaker	Heavy Multi-Run Copper Busbar Trunking (BBT) or Dual 5000A ACBs with Interlocked Tie	Thermal-magnetic or electronic trip unit coordination
Recommended Low Voltage Cabling / Busbar	10,000A Sandwich Copper Busbar Trunking (BBT) or 16 Parallel Runs 3.5C 300mm² Cu	Sized for <2.5% voltage drop at full load run
Civil Foundation Mounting	Engineered Outdoor Reinforced Concrete Bay with 100% Oil Catchment Sump & Fire Wall	A 7000 kVA (7 MVA) substation operates under DISCO B-4 heavy industrial tariff (LESCO, FESCO, GEPCO, IESCO, MEPCO, PESCO, KE). Regulations mandate a dedicated 11kV or 132kV incoming Vacuum Circuit Breaker (VCB) panel with numerical differential (87T), overcurrent/earth fault (50/51/51N), trip circuit supervision (95), dual copper grounding grids (<0.5 Ohm), and dedicated CT/PT metering room.

Industrial Applications

Where is a 7000 kVA (7 MVA Power Substation) Transformer Deployed in Pakistan?

Real-world application engineering scenarios across Pakistani heavy industry, steel production, and transmission substations:

Built to withstand severe cyclic thermal shocks, harmonic resonance, and high electromagnetic short-circuit stresses from medium-frequency solid-state induction melting crucibles in Badami Bagh, Sheikhupura, Hattar, and Hub.

Reinforced core clamp plates with high-tensile fiberglass tie rods
Dual-float Buchholz relay, magnetic oil gauge (MOG), and dial thermometers with SCADA trip contacts
Detuned harmonic filtering coordination for 5th, 7th, and 11th current harmonics

Supplies massive steady current to high-voltage thyristor/diode rectifier units producing caustic soda, chlorine gas, and industrial chemicals under continuous 24/7/365 chemical duty.

Class-F high-temperature insulation with vacuum pressure impregnation (VPI)
On-Load Tap Changer (OLTC) with 17-step automatic voltage regulator (AVR)
Redundant radiator banks with dual cooling fans (ONAF cooling boost)

Serves as the central utility intake substation stepping down primary transmission grid power for multi-unit industrial parks, textile spinning complexes, and large-scale manufacturing zones under DISCO B-4 tariff.

Numerical differential protection relay (87T) and restricted earth fault (64R)
Neutral grounding transformer (NGT) with neutral grounding resistor (NGR)
Full compliance with WAPDA P-SPEC, IEC 60076, and NTDC Grid Code

Quality Assurance

Testing Protocols & DISCO Grid Energization Approval

Every TransfoLine 7000 kVA (7 MVA Power Substation) transformer undergoes stringent factory routine testing before dispatch to ensure 100% first-time approval during DISCO departmental inspection:

Mandatory Routine Tests Lab Certified

Insulation Resistance (Megger Test) Tested at 2500V DC (HV-LV, HV-Earth, LV-Earth) ensuring insulation values exceed 2,000 Mega-Ohms.

Winding DC Resistance Measurement Measured across all primary tap positions and secondary phases using Kelvin bridge for balance verification.

Voltage Ratio & Vector Group Verification Confirming exact transformation ratio and Dyn11 30-degree phase shift.

Oil Dielectric Breakdown Voltage (BDV) Verified with 2.5mm sphere gap electrode test exceeding 50 kV (brand new units exceed 60 kV).

Separate Source AC Withstand Test HV winding tested at 28 kV AC for 60 seconds; LV winding tested at 3 kV AC for 60 seconds.

DISCO Inspection & NOC Process Turnkey Assistance

Load Sanctioning File Preparation Preparation of single line diagrams (SLD), connected load lists, and tariff change applications.

Substation Civil Pad Inspection Verification of concrete foundation dimensions, gravel oil-sump, and earth pit clearance distances.

Dual Earth Pit Verification (<0.5 Ohm) Separate chemical/copper plate grounding pits for transformer tank body and neutral star point.

Departmental Testing & Meter Sealing Witnessing of testing by DISCO M&T (Metering & Testing) engineers and installation of bidirectional TOD meters.

Direct Quotation

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Specify your factory or substation parameters. Our high-voltage engineering team will calculate your feeder requirements and deliver an itemized quotation within 2 business hours.

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Frequently Asked Questions

Frequently Asked Questions — 7000 kVA (7 MVA Power Substation)

Technical answers to common commercial and engineering questions regarding 7000 kVA (7 MVA Power Substation) power transformers in Pakistan:

What is the full load secondary current of a 7000 kVA (7 MVA) transformer?