Depending on the electric dehydrator volume, combination of physicochemical and electro-physical oil characteristics a wide range of power units is offered e.g. 25; 37,5; 50; 75; 100; 150; 200 and 250 kVA. This allows the use of a single power unit per one electric dehydrator, to optimize its design and to reduce the price.

The advantages of high voltage power supplies:

• 100% reactance, resistant to overloads during the short circuits of electrodes;
• no additional control units for transformer are required;
• wide range of output voltage values (12; 16,5; 20; 23; 25 kV AC) by use of a tap-switch;
• optional design with high output DC voltage c/w 5 position tap setting that gives enhanced efficiency to electric desalter units for refinery applications where the quality of dehydration and desalting is critically important;
• reliable design with leak proof transformer housing ensuring stably high dielectric properties of transformer oil and its long service life;
• connection with entrance bushing of electric dehydrator via a regular cable in an oil-filled sealed off coupling that provides long service life, reliable explosion protection and weather resistance;
• oil temperature, level and pressure control devices along with oil heating capability for maintaining oil dielectric properties at shutdowns in cold weather conditions.

CJSC Neftech is an official dealer and representative of the company NWL Transformers, Inc. in Russia and CIS. For more than 50 years NWL Transformers, Inc. remains the main manufacturer and the supplier of the high-voltage power units for many world-known producers of the electric dehydrators.

CJSC NEFTECH supplies plants, oil-producing companies and refineries with high-voltage power units that aim to complete and modernize the electric dehydrators thereby increasing their efficiency and reliability.

Furthermore, CJSC NEFTECH provides services like  specifying optimum parameters and power unit type (depending on application conditions); implements necessary modifications in design, in instrumentation and control system; manufactures new high-voltage bushing assemblies and executes supervision and commissioning activities.

AC power supply for oil with 100% reactance (W=25-250 kW)

Electrical Specification Sheet:

Rated input voltage 400 VAC, 3PH, 50Hz.

The selection of nominal AC output voltages are as follows (Five output voltages can be selected through five position tap selector switch)

• Position 1 —  12 kV AC;
• Position 2 — 16.5kV AC;
• Position 3 — 20 kV AC;
• Position 4 — 23 kV AC;
• Position 5 — 25 kV AC.

Voltage tertiary windings:

• Both tertiary windings are rated 100V nominal at 2 amps +5% output.  Actual tertiary voltage will be dependent upon actual input voltage to its corresponding transformer and will range from 0V – 100V.  Since both tertiary windings from the two transformers are wired in series within the unit, the total feedback from the voltage feedback circuit will range from 0-200vac.
•  All units contain an internal thermal switch.  This is a normally closed bi-metallic switch that will open on an over-temperature rise.  The switch is potted within the primary of the main transformer.  It is there as a protection means in the unlikely event that the unit overheats.  It is designed to open at 81 degrees Celsius.

Applicable Standarts:

• UL (60079-0, 60079-6, 60079-7) per SGS #FF126-05-0101;
• CSA (E79-0, E79-6, E79-7) per QPS #LR 1001-2;
• Ex (EN50014) Per Demko No/02 Atex 130819x and 02 Atex130820x.

Physical Specifications:

Dielectric cooling fluid:

• Mineral oil type Gross Grade 206
• Silicone fluid Dow corning 561

The painting method:

• industry standard ASA61 gray pained finish;
• Megatran50 premium paint system;
• Unpainte: 316L dstainless steel.

Features on power supply include the following:

• Copper radiator grille
• Oil Heater: 120V additional heater (B1,B2)
• Oil level indicator (D1,D2)
• Pressure gauge on the main tank
• Temperature gauge on the main tank