Transformer Repair and Maintenance

TRANSFORMER REPAIRS

Native American Transformers Services, Inc. has information, equipment, suppliers, and experienced personnel with many different transformer manufactures allowing us to perform many types of repairs.

Native American Transformer Services, Inc. has experience with many transformer manufactures, such as, ABB, GE, SPX (Waukesha), Hyundia, HICO, Delta Star, Niagara, Virginia Transformer, Mistsubishi, and Siemens to name a few.

These brands, however, do not encompass our full range of capabilities: we can work on almost any transformer, performing repairs as listed below.

RADIATOR AND COOLER REPLACEMENT

With NATS engineering expertise combined with high quality suppliers, we can provide replacement radiator and/or cooler packages ready to install. Installation packages can include; installation drawings, radiators/coolers, pumps, piping, gaskets and hardware, or any combination of these items. In addition to supplying the parts, NATS can field install the equipment. If specifications and/or drawings are not available a technician/engineer can make a site visit to acquire any necessary dimensions and information.

BUSHING REPLACEMENT

NATS has relationships with most bushing suppliers/manufactures allowing us to acquire a direct replacement bushing or determine an acceptable replacement for bushings that are obsolete and no longer manufactured. If modifications to leads and/or connections to accommodate dimensional differences are nessecary they can be identified and adapter leads and/or connections can be made during installation. Complete installation service may include oil handling, lead modification (if necessary), vacuum fill (if required) and testing. If information on the bushing requiring replacement is unavailable, a ATS technician/engineer can make a site visit to acquire any needed dimensions and/or equipment information.

GAUGE REPLACEMENT AND CALIBRATION

In addition to replacing existing gauges, NATS can add gauges to transformers originally supplied without gauges, and/or provide complete monitoring systems. Scope(s) of work can include supplying new or replacement gauges, mounting gauges on tank, running line for temperature probe(s), modifying tank to add probe(s), wiring from the control box to gauges, calibrating the equipment and verifying operation.

LEAK REPAIR

Oil and nitrogen leaks are costly and often occur due to extreme operating and environmental conditions, leaks can occur at gaskets, fittings, welds and points of physical damage. Most leaks are repairable, NATS has the ability to find leaks and make repairs. Some of our resources include experienced personnel; equipment necessary to handle the project, store oil and vacuum-fill; certified, experienced welders and specialized procedures.

Transformer Maintenance

Native American Transformer Services, Inc. maintenance service can work on all of your substation equipment.

This includes transformers, circuit breakers, switchgear, regulators, control cabinets, housings, and structures, to name a few. NATS experience includes everything from pad-mounted transformers through 765kV equipment.

Maintenance painting can minimize equipment downtime; repainting of radiators at the first signs of wear, may save you from the higher costs of radiator replacement at a later date.

As a full service maintenance supplier, we can incorporate painting into a contract with other repair work, saving you from hiring multiple contractors to accomplish a complete scope of work.

Painting & Encapsulation

We can comply with your paint specifications or use our own. Paint can be applied by spray, brush or roller on the main tank and by flow coat on radiators. Surfaces are prepared in a number of ways depending on their condition: grinding, sandblasting, needle gun, phosphoric acid wash, degreasers, pressure washing, sodium hydroxide stripping of radiators and special rinse for salt removal. All unpainted surfaces are either taped off or bagged prior to painting.

NATS knows environmental regulations and how to comply. If lead exists in the paint, our crews have the proper protective equipment for working with lead paints. We can collect the wash water in order to do the job in an environmentally-friendly manner; our painting system then encapsulates the lead paint so it doesn’t get carried into the ground.

REGASKETING

With the need to keep transformers on-line the cost of a transformer leaking can be high.

Our teams are experienced with some of the most common problems as listed below.

Moisture and oxygen can enter a transformer through leaking gaskets causing accelerated aging of insulation failure.
Oil getting onto the ground and possibly into groundwater can be expensive to remedy; leaking oil can carry lead from transformer paint (if paint is lead-based) into the ground causing further contamination.
Leaks above the transformer oil can allow the nitrogen blanket to escape, causing more frequent nitrogen bottle replacement if provided with a positive pressure system.

NATS can fix the leaking location(s) or at your request or completely regasket all transformer openings and reprocess the oil to put equipment back in good condition; the scope of our services is up to you our customer.

At a minimum we will perform the following steps to Regasketing a Transformer:

Notice to Proceed and Isolation procedures

Ground Transformer

Establish Baselines

Analyze Baseline Data for Problems

Drain Oil

Regasket All Openings on Outside of Tank

Visually Inspect LTC for Problems and Advise

Pressure Test with Dry Air

Perform Vacuum Drop Test

Pull Vacuum/Process Transformer per Customer Specifications

Refill Transformer with Vacuum Degasified Oil

Implement System Checks

Compare System Checks to Baselines

Walk-Through with Customer

Unground Transformer

Issue Final Project Report

OUR WORKS

NATS has the equipment, experience and capability to complete repairs, upgrades, insulation dryouts, bushing replacements, LTC repairs/upgrades, and FR3™ retrofills.

These are but a few services we perform, please call or email for a complete list.