Copper Core & Coil Transformer

Transformer Stomach Pain • Normal Operation: Transformer internal structures and

windings are subjected to mechanical forces due to the magnetic forces.

• Through fault – current passing through a transformer. Forces can reach millions of pounds, pulling the coils up, down, and apart 60/50 times per second.

Transformer Stomach Pain • By designing the internal structure very strong to withstand these forces

over a long period of time, service life can be extended.

• Notice in Figure 1 that the internal low-voltage coil is being pulled downward, while the high-voltage winding is pulled up, in the opposite direction.

• At the same time, the right-hand part of the figure shows that the high-

and low-voltage coils are being forced apart.

Transformer Stomach Pain • Keep in mind that these forces are reversing 50/60 times each

second. It is obvious why internal structures of transformers must be built incredibly strong.

• Many times, if fault currents are high, these forces can rip a transformer apart and cause electrical faults inside the transformer itself. This normally results in arcing inside the transformer that can result in explosive failure, submitting the equipment to catastrophic failure.

Free Bucking Mechanical Failure

The picture to the side is an example of a free bucking mechanical failure of an inner winding resulting from radial forces in compression on the winding. Note, even though there is mechanical failure, there wasn’t a dielectric failure of this winding yet.

Shouldn’t Your Transformers Be As Tough As the People Using Them?

Duratrans™ Transformer

“The New Industry Standard”

Duratrans Transformer

Duratrans Power Range

• KVA Range - 75kVA to 6000kVA

• Voltage - up to 25kV

• Available with dual primary voltages

• Void free windings

• Superior mechanical strength

• Designed for extreme environmental conditions

• Tested per ANSI C57.12.91 Thermal performance

Duratrans™ Transformer

• Proven Harsh Environment Technology

• Coil Distortion Prevention Technology

• Corrugated Duct Technology

• Unique OVAL Technology

Advantages of Duratrans Transformer

• Safety for people and property

• No Fire Hazard

• No maintenance or pollution

• Applicable for damp and high dust contaminated environments

• Improved performance against seismic and high vibration areas

• Environmentally Friendly

Duratrans Technology Application Types

• Distribution Transformers

• Substation Transformers

• VFD transformers

• Rectifier Transformers

• Booster Transformers

• Auto Transformers

• Shovel Duty Transformers

• Mine Load Centers

Duratrans Benefits

• Non Explosive, Flame Retardent and Self Extinguishing

• Can be designed for use in tempretures -60c to +60c (40c is ANSI standard)

• Ideal for high humidity and where splasing water is an issue

• Coils are moisture resistant

• No timely drying out period required prior to energizing

• Seals out all environmental contaminants

• Mechanicly robust to prevent coil distortion

• Corrugated ducting to increase cooling efficiency

Duratrans™ Transformer

Power Distribution - Surface

Power Distribution - Underground

What is an Arc Flash..? • “Where a flashover of electric current leaves

its intended path and travels through the air from one conductor to another, or to ground.

• The Results are often violent when a human is in close proximity to the arc flash, serious injury and even death can occur.”

- OSHA and NFPA (National Fire Protection Association)

• Arc Flash can be caused by:

• Dust

• Dropping tools

• Accidental touching

• Condensation

• Material failure

• Corrosion

• Faulty Installation

• Severity Factors

1. Proximity of the worker to the flash

2. Temperature

3. Time for circuit to break

• Typical Results • The Solution

• Burns (immediate and cell deterioration following)

• Fire

• Flying objects (molten metal)

• Blast pressure (upwards of 2,000 lbs. / sq. ft.)

• Sound Blast (140 db – loud as a gun)

• Heat (upwards of 35,000°F… 5 times surface temperature of the sun

• Costs: Sometimes in excess of $1 million

Arc Guard™ Mine Power Center

• Eliminates Potential Arc Flash Injury

• Passive Control of Arc

• Does NOT depend on light or electronics

• Complies with ANSI – IEEE Arc Resistant Requirements

• All surface-underground electrical equipment

• Type tested at KEMA Power Labs

Arc Guard™ Mine Power Center

Hot Circuit Detector – Smart Plug

• High Impedance 3 phase voltage detection

• Loss of phase trips circuit • Reverse rotation trips circuit • 120v-25kv voltage range • Phase sequence +/- • 240VAC, 10amp contact

output for control • The only commercially

available connector with voltage sensing

• May be gear or line mounted (480-595v)

Thank You… Questions