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Explosion Proof Transformer | Explosion Proof Enclosures

Haz-Pac and SilPac Transformers for perilous, dangerous and hazardous locations

Hazardous Locations are well defined by the National Electric Code (NEC®) for good reason. Choosing the wrong transformer for use in perilous environments containing volatile gases, dust, liquids or fibers can lead to serious consequences.

Our Silica Resin Encapsulated Transformer is the result of many years of continuous refinement. Two product types, recognized in the market as the Haz-Pac and SilPac, were developed and expanded as a result of a growing need for a compact and economical dry type transformer that was impervious to harsh environmental conditions, such as those encountered in chemical plants, refineries, dairies, marinas, shipboard use, etc. Product durability, quiet operation, and flexibility in designing the encapsulated style transformer for your application are clear advantages offered by the Olsun brand. Olsun Electrics Haz-Pac™ transformer line is designed and built specifically for hazardous locations in compliance with article 500 of the NEC and is UL* listed for Class I, Division 2, Groups C and D locations. And with a North American Temperature Classification of T3C, Haz-Pac keeps its cool under load — when you and the surroundings demand it. Couple our dedicated hazardous duty design with high short-circuit strength, 80° C rise availability and Olsun Electrics’ industry proven reliability and you’re literally playing it safe in choosing Olsun for long life in your application.

* UL Listing applicable to single-phase sizes up to 50 kVA and three-phase sizes up to 150 kVA, through 600 volts.

Hazardous Application Typical Specification

Per the approved electrical plans, furnish and install dry type, hazardous duty rated transformers as manufactured by Olsun Electrics Corporation or approved equal. Single-phase transformers up to 50 kVA and three-phase transformers up to 150 kVA (through 600 volts) shall meet the requirements of UL Standard 1604, latest revision, entitled “Electrical Equipment for use in Class I and Class II, Division 2, and Class III Hazardous (Classified) Locations”.

Transformer sizes (kVA ratings) shall be as shown on the electrical plans or transformer schedule. Primary taps shall be full capacity, with a minimum of 2, 5% below nominal primary voltage rating on kVA sizes through 15; 2, 2.5% above and below nominal primary voltage rating on kVA sizes above 15 kVA.

All transformers shall have a maximum full load temperature rise of 115 degrees C above a 30 degree C ambient. All insulating materials used shall have a minimum UL 180 degrees C system rating. Encapsulating resin shall have a minimum UL temperature system rating of 180° C. The temperature rise shall be designated on the nameplate.

The transformer cores are to be constructed of high grade, non-aging silicon steel laminations with high magnetic permeability and low hysteresis and eddy current losses. Magnetic flux densities shall be kept well below the saturation point. The core laminations shall be clamped together with heavy structural steel angles.

The enclosure shall be 14 gauge, or heavier, type 316 stainless steel in accordance with the latest NEMA, ANSI and UL requirements for outdoor enclosures. The enclosure shall be provided with suitable lifting means. Jacking and lifting provisions shall be provided on all units weighing in excess of 600 pounds. All enclosure seams shall be continually welded using compatible welding rod and all weld seams shall be ground smooth. An ANSI 61 gray, powder coat finish shall be applied to a minimum thickness of 1.5 mils.

The enclosure shall have adequate surface area to limit the maximum temperature rise of the enclosure to 65 degrees C above a 40 degree C ambient at full load and rated voltage.

NOTE: Enclosures can be CRS—designated NEMA 4.

The sound level of the transformer shall be guaranteed by the manufacturer to be at least 3 dB lower than that stated in ANSI C57.12.01 latest revision, for dry type ventilated transformers. The basic impulse levels (BIL) shall be a minimum 30 kV for all windings rated 1000 volts or higher and 10 kV for all windings less than 1000 volts.

Contractors and/or suppliers wishing to furnish equals to the units specified shall supply the Engineer with certified drawings and performance data, including sound level, on similar transformers, plus a sample for the Project Engineer’s inspection at least 10 days prior to the bid date.

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