Specialists in the EPC design and construction of
high voltage ( 3.3 kV – 750 kV) grid connections.

HV Projects

H&MV Engineering offer comprehensive EPC services – from design to supply and installation to commissioning.

We specialise in completing 3.3 kV to 750 kV transmission and distribution networks, project supervision and management.


H&MV has developed a motivated team of High Voltage design engineers with specialist expertise in substation and transmission circuit design & build and contestable grid connections.

H&MV can provide:

  • Short Circuit and Discrimination Studies
  • Cable & Conductor Calculations
  • Switchgear Design
  • Transformer Design
  • Substation Layout Design
  • Steel Calculations and Design
  • Earthing Design
  • Network Design
  • Protection Scheme Design
  • Load Studies
  • Busbar Calculations
  • CT Burden Calculations
  • Lightning Studies


Correct installation will ensure a high degree of operational reliability.

To achieve a trouble-free start up, it is required that High Voltage service installation and commissioning procedures are followed.

The H&MV Engineering teams focus specifically on installation and commissioning of the delivered products including related control equipment. All H&MV staff and engineers can draw on extensive practical experience gained in many installation and commissioning assignments, both at domestic sites and abroad.

Our expertise covers all the different issues of installation and commissioning of transmission and distribution networks from 3.3 to 750 kV, employing our state-of-the-art testing and diagnostic facilities to assure excellent service results.


The testing and commissioning of high voltage substations is a core part of H&MV Engineering.

Our capabilities range from smaller distribution substations on the consumer side to larger transmission and generation substations for TSO’s, DNO’s, power stations, data centres and wind farms.

We have team’s of highly trained commissioning engineers offering a complete range of services utilising the latest technologies and procedures.


State of the Art Test Equipment
  • Omicron CMC 356 x 3
  • Omicron CPC 100 and all accessories x 2
  • Omicron FRA
  • Omicron DIRANAHV testing equipment
  • Programma Sverker 650 x 5
  • Programma Primary injection kit 600A x 5
  • Programma Battery discharge kit
  • Programma Circuit breaker timing kit
  • Programma low ohm tester 200A
  • Megger 10kV Insulation resistance tester 10kV
  • Megger 5kV Insulation resistance tester x 15
  • Fluke dry well calibrator
  • Fluke mA simulators x 2
  • Buchholz test tool
  • AC pressure tester 72kV
    And much more

HV Projects Case studies

Asset Management

Why do you need High Voltage Asset Management?

In most cases your HV Equipment and Systems are critical to your plants reliability because there is often no redundancy and the systems can be the single point of failure for your facility.

In order to maintain the equipment in a safe, reliable and functional state, regular predictive and preventive maintenance is required.

HV Maintenance can be divided into two categories – Non Intrusive and Intrusive:

Non Intrusive or predictive maintenance should be carried out while your plant is live and equipment is fully loaded and up to operational temperature.

Intrusive or preventive maintenance is carried out while the equipment is shutdown, isolated and locked out.

HV Non Intrusive Maintenance includes:

• Partial Discharge Testing – PD

• Equipment Visual Inspection

• Voltage, Amps & Temperature Readings

• Infrared Thermographic Imaging – TI

• Oil Sample Analysis

• Power Quality analysis

HV Intrusive Maintenance Includes:

• HV & LV Switchgear Inspection & Testing

• SF6 Switchgear gas handling equipment and leak detection, disposal and recycling

• Transformer Inspection & Testing

• Transformer Condition Assessment

• Tap Changer Maintenance

• Busbar Inspection

• Cable Termination Inspection

• Cable VLF & Partial Discharge

• Protection Relay Inspection & Testing


Please have a look at our information packs.

If you are interested in any of the services we provide, please do not hesitate to contact us to discuss your requirements.


CT & VT Services

H&MV Engineering offer the following Current Transformer (CT) and Voltage Transformer (VT) services.

Ultrasonic Partial Discharge Testing

Non-intrusive discharge monitoring is a very effective predictive maintenance test for MV motors, MV generators and MV switchgear as well as other electrical distribution equipment.

Protection Relay Services

We are capable of testing all protection relays from the old induction disc type to the modern multifunctional electronic relays.

Maintenance of low voltage circuit breakers

The deterioration of a low voltage circuit breaker is normal and this process begins as soon as the circuit breaker is installed. If deterioration is not checked, it can cause failures and malfunctions.


Dielectric Fluid Sampling & Analysis

H&MV Engineering takes oil samples to perform a Dissolved Gas Analysis (DGA) and an Oil Content and quality evaluation of a transformer and switchgear insulating fluids in accordance with specifications.


Transformer Condition Assessment

Testing to assess the health of power transformers and diagnose problems is of utmost importance to ensure the long term and safe operation of these very expensive power assets.


Cable Fault Locating

Although today’s power cable is designed for long life, failures can still be experienced. H&MV Engineering has taken cable fault locating from a hit or miss “art” to an exact “science.”

Thermal Imaging

Using Thermal Imaging we are able to rapidly test electrical systems for hot spots caused by loose connections or damaged and overloaded wiring before further damage is caused to your equipment.


Power Quality Analysis

Much of the electrical equipment in an industrial facility requires high-quality electricity; it will not tolerate sags, swells, transients, or harmonics, and it certainly will not tolerate power outages, no matter how short-lived.

Preventative Maintenance

It’s natural for electrical equipment to degrade over time, but it doesn’t necessarily have to fail. Preventive Maintenance Services from H&MV Engineering will evaluate the condition of your equipment and determine the most cost-effective and manageable solution to ensure its overall performance, safety and reliability.

Soil Resistivity & Earth testing

Effective earth grounding is essential for grounded AC and DC electrical equipment and distribution systems. Effective grounding provides the level of safety required to protect personnel and equipment from shock and fire hazard.

Circuit Breakers

HV Circuit Breakers (CB’s) are electrically operated switches designed to protect your electrical circuits from damage. Regular inspection and servicing is essential to ensure the reliability of your system and safe operation of the circuit breaker to protect your power systems.


Battery Testing

Battery banks provide an independent source for switchgear control, engine generator set starting, signal and communications systems, laboratory power, emergency lighting, and other applications. Batteries are the essential component of any Uninterruptible Power Supply (UPS).

HV Cable Partial Discharge Testing

Partial discharge mapping is a non-destructive
technique for condition monitoring,
assessment and commissioning
of high voltage cables.

Asset Management Case studies

Asset Management
Case studies

Training Centre

City & Guilds High Voltage Switching & Operations Course

High voltage systems require specific knowledge, expertise and competency to operate in a safe and competent manner.

H&MV Engineering have recognised that a significant gap exists in this area and we have put significant resources, experience and development into this course to address that shortfall.
This is the only one of its kind to be Accredited by City & Guilds in Ireland.

We offer full (5 days) and refresher (2 days) courses – contact us today for more details.

Training subjects

1. Principles of Electrical Safety

2. Lock-Out & Tag-Out (LOTO) & Testing of Isolations

3. Electrical Drawings and Switching Plans

4. Electrical Safety Legislation and Standards

5. Principles of Arc-Flash and Arc-Blast

6. Personal Protective Equipment (PPE) and High Voltage Test Equipment

7. High Voltage Switchgear and Transformers

8. General Electrical Theory and Concepts

9. Electrical Circuits and Protection

10. Principles of Risk Assessment

Who is it for?

The course is designed to be suitable for varied groups including:

• Facilities and Maintenance Managers

• Facility Engineers and Technicians

• High Voltage System Operators

• Plant Electricians

• Maintenance Technicians

It is recommended that candidates have 4 years of electrical experience.

For bookings please email training@hmveng.ie

What information do I need to book?
  • Company Details

– Company Name
– Company Address
– Company Contact Name
– Company Contact Number
– How did you hear about us?

  • Participants Details:

– Name
– Address
– Mobile Number
– Email Address
– Special Conditions eg. Learning difficulties, dietary requirements
– Position
– Number of Years of Electrical Experience
– Current Daily Duties in Position
– Qualifications
– Associated Courses
– High Voltage and/or Switching Experience


  • Credit Card Details
    (Alternative metods of payment can be arranged, please email us at hvtraining@hmveng.ie )