⚡ Certified Transformer Specialists Since 1998

Power
Transformer
Services

Comprehensive lifecycle management for power transformers — from technical studies and expert diagnosis to precision maintenance, spare parts supply and on-site intervention.

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1200+
Transformers Serviced
27
Years of Experience
98.6%
Uptime Guaranteed
60+
Industry Clients
24/7
Emergency Support
Power engineers at work
// About VoltCore

Engineering Excellence
In Every Watt

VoltCore is a leader in power transformer lifecycle services across industrial, utility, and infrastructure sectors. With over 27 years of field experience and a team of certified high-voltage engineers, we deliver technical precision you can trust — before, during, and after every transformer installation.

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Diagnostic Expertise Advanced oil analysis, DGA, insulation testing, thermography and partial discharge detection.
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Certified Engineering Team IEEE, IEC and ISO 9001 certified specialists with decades of real-world field experience.
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Full-Scope Services From feasibility studies and procurement advice to preventive maintenance schedules and emergency repairs.
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Remote Monitoring IoT-based online monitoring solutions with real-time alerts, reporting, and performance dashboards.
// Core Services

What We Do

Four pillars of transformer excellence — each delivered with meticulous engineering discipline and a commitment to zero unplanned outages.

Transformer maintenance
01 / 04
Maintenance & Repair
Scheduled and corrective maintenance programs that maximize transformer longevity and operational reliability. Our teams operate under strict safety protocols and IEC standards.
  • Preventive maintenance scheduling (annual, biannual)
  • Oil filtration, dehydration and regeneration
  • Tap changer inspection and reconditioning
  • Bushing and seal replacement
  • Insulation resistance and winding tests
  • Emergency breakdown response (24h)
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Technical studies
02 / 04
Technical Studies
In-depth engineering studies supporting decision-making for transformer procurement, integration, protection and network optimization.
  • Load flow and short-circuit analysis
  • Transformer sizing and specification
  • Protection coordination studies
  • Harmonic distortion assessment
  • Energy efficiency and loss evaluation
  • Feasibility reports for HV/EHV projects
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Expert diagnostics
03 / 04
Expert Diagnostics
Third-party expert assessments and forensic analysis to identify root causes of failure, evaluate transformer health, and provide independent technical opinions.
  • Dissolved Gas Analysis (DGA) interpretation
  • Frequency Response Analysis (FRA)
  • Partial discharge measurement and mapping
  • Thermographic infrared inspections
  • Insulation power factor and capacitance tests
  • Post-incident forensic reporting
Learn More →
Spare parts supply
04 / 04
Spare Parts Supply
Sourcing, quality-control and rapid delivery of OEM-grade transformer components from trusted global manufacturers, with full technical traceability.
  • Bushings (HV, LV, neutral)
  • On-load tap changers (OLTC) and DETC
  • Buchholz relays and protection devices
  • Cooling fans, radiators and pumps
  • Gaskets, seals and conservators
  • Winding conductors and core materials
Browse Parts →
// Our Methodology

How We Work

A structured, transparent approach from first contact to long-term partnership — ensuring nothing is left to chance.

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1
Initial Assessment
On-site visit and data collection. Review of transformer nameplate, history, and operating conditions.
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2
Technical Study
Engineering analysis, test results interpretation, risk classification and health index scoring.
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3
Proposal & Planning
Detailed intervention plan with timelines, cost breakdown, safety procedures and resource allocation.
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4
On-Site Execution
Certified engineers perform all work under IEC standards with real-time quality monitoring and documentation.
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5
Reporting & Follow-up
Full technical report delivery, recommendations for next cycle and optional remote monitoring activation.
Engineer performing transformer diagnostics
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IEC 60076 Certified All studies comply with international standards
// Technical Expertise

Studies &
Expert Analysis

Our engineering team delivers comprehensive technical studies that guide critical decisions throughout your transformer's lifecycle — from specification and procurement to decommissioning.

01
Power System Studies

Load flow analysis, fault calculations and protection coordination to ensure your transformer is properly integrated and protected within the power network.

02
Dissolved Gas Analysis (DGA)

Detection and trending of fault-indicating gases dissolved in transformer oil. DGA is the most effective tool for early fault detection before catastrophic failure occurs.

03
Dielectric & Insulation Studies

Comprehensive evaluation of insulation system condition through power factor testing, polarization index measurements, return voltage analysis, and FDS/RVM tests.

04
Frequency Response Analysis (FRA)

Fingerprint-based winding integrity verification. Used to detect winding deformation, movement, and insulation changes after short-circuit events or transportation.

05
Feasibility & Life Extension Studies

Economic analysis comparing refurbishment versus replacement, with full health index assessment and remaining life estimation based on actual field data.

// Maintenance Programs

Protecting Your
Critical Assets

Our structured maintenance programs are tailored to transformer type, age, loading profile, and criticality — from routine inspection to full reconditioning.

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Preventive Maintenance

Scheduled interventions to prevent unplanned outages. We develop customized maintenance calendars aligned with your operational constraints and IEC/IEEE recommendations.

  • Annual inspection & oil sampling
  • Visual inspection and leak detection
  • Protective relay and OLTC testing
  • Grounding system verification
  • Cooling system performance check
  • Full maintenance report & recommendations
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Corrective & Emergency Repairs

When transformers fail, rapid response is critical. Our 24/7 emergency teams can mobilize within hours to diagnose and restore power with minimal downtime.

  • Emergency on-site intervention (24h/7d)
  • Fault diagnosis and damage assessment
  • Active part repair and rewinding
  • Tank welding and oil-related repairs
  • Temporary transformer supply (bypass)
  • Root cause analysis report
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Oil Treatment & Filtration

Transformer oil is the lifeblood of insulation. We restore oil to original performance standards using state-of-the-art vacuum dehydration and filtration rigs.

  • Vacuum oil filtration and dehydration
  • Oil regeneration with Fuller's earth
  • Acid neutralization and inhibitor dosing
  • Oil quality testing (IEC 60296)
  • Complete oil replacement if necessary
  • Mobile units for on-site treatment
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Tap Changer Overhaul

The tap changer is the most mechanically active and failure-prone component. We perform complete OLTC reconditioning to OEM specifications and test all functions rigorously.

  • Contact inspection and replacement
  • Diverter switch overhaul
  • Drive mechanism inspection & lubrication
  • Oil compartment cleaning and refilling
  • Transition resistance measurement
  • Dynamic resistance measurement (DRM)
// Components Supply

Spare Parts &
Components

We source and supply high-quality OEM and compatible spare parts for all major transformer manufacturers — ABB, Siemens, Schneider, ABB, Alstom, Hyundai and more. Every component includes full traceability documentation and test certificates.

High voltage bushings
Insulation Components
HV/LV Bushings

Oil-paper, RIP, RIS and condenser-type bushings for all voltage classes from 11kV to 765kV. Supplied with full test reports and packing solutions.

OEM Compatible
Tap changer
Switching Components
On-Load Tap Changers

Complete OLTC units and sub-components for MR, ABB, and Reinhausen types. Includes contacts, selector switches, diverters and drive mechanisms.

Genuine Parts
Protection relays
Protection Devices
Buchholz Relays & Sensors

Gas-actuated protection relays, pressure relief devices, winding temperature indicators, oil level gauges and magnetic oil level indicators.

Certified
Cooling system
Cooling Systems
Radiators, Fans & Pumps

ONAN/ONAF/OFAF/ODAF cooling components including corrugated radiator panels, cooling fans, oil circulation pumps and heat exchangers.

All Voltage Classes
Oil conservator
Tank & Oil System
Conservators & Gaskets

Expansion conservator tanks, flexible membrane bags, silica gel breathers, drain valves, sampling valves and complete sealing kits for all transformer types.

Custom Sizing
Winding and insulation
Active Part Components
Windings & Insulation

Copper and aluminium winding conductors, pressboard, crepe paper, insulation cylinders and kraft paper for reconditioning and full rewinding projects.

IEC 60547 Grade
Certifications & Standards
ISO 9001:2015 IEC 60076 IEEE C57 OHSAS 18001 IEC 60270 IEC 60137 ISO 45001 EN 50110
// Client Testimonials

What Our Clients Say

"

VoltCore's diagnostic team detected a developing fault in our 63MVA transformer 6 months before any visible symptoms. Their early intervention saved us an estimated $2.3M in replacement costs and avoided a critical production outage.

KH
Khalid Haddad
Chief Engineer — Sonelec Industrial
"

We've contracted VoltCore for annual maintenance on our 27-unit substation fleet for the past 9 years. Their documentation quality, technical depth, and response time are second to none in North Africa.

FO
Fatima Ouazzani
Asset Manager — Regional Power Grid Authority
"

The power system study VoltCore delivered for our new cement plant gave us a complete view of protection coordination and transformer selection. The report exceeded all our internal standards — truly exceptional work.

AM
Amine Mrabet
Project Director — Atlas Ciment Group
// Get In Touch

Request a
Consultation

Whether you need an emergency intervention, a scheduled assessment, or a technical study — our team is ready to respond. Reach out and we'll get back to you within 4 business hours.

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Head Office Zone Industrielle Ain Sebaâ, Casablanca, Morocco
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24/7 Emergency Hotline +212 5 22 00 00 00
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Technical Inquiries technical@voltcore-services.com
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Office Hours Monday – Friday, 08:00 – 17:30 (Emergency: 24/7)