SECTION 16460
DRY TYPE DISTRIBUTION TRANSFORMERS
PART 1 - GENERAL
1.01
DESCRIPTION
A.
B.
1.02
General: Provide dry type transformers, complete, as shown and specified
per Contract Documents. Principal items include:
1.
Power transformers.
2.
Control transformers.
Other Applicable Sections: Requirements of Division 1 and Section
16050 apply to work of this Section.
SUBMITTALS
A.
Procedures: Refer to Division 1.
B.
Requirements: In addition to the requirements of Section 16050 submittal
material shall include copies of descriptive data for all products and
materials.
C.
Shop Drawings: Submit for all work of this Section.
PART 2 - PRODUCTS
2.01
POWER TRANSFORMERS
A.
Dry Type: Integral, self-cooled, enclosed distribution transformers of the
two-winding type.
B.
Capacity and voltage ratings as indicated.
C.
NEMA Standard Taps: If taps are not standard, equip transformer with
two 2-1/2% FCAN and four 2-1/2% FCBN taps. Tap leads shall be
terminated on internal block with lugs for connection of incoming conductors.
2.02
D.
Where neutral connection is indicated, attach to bolt and lug inside
enclosure and extend bolt through enclosure to permit external ground
connection.
E.
Vibration dampers (Korfund Company or equivalent) separating core and
coil assembly from the structural members of the enclosures. Sound levels
shall be 3 dB lower than NEMA Standard for each particular size.
F.
Class H insulation, having a 150oC temperature rise above a 40oC
ambient, when operating continuously at full load without loss of normal
life. Construct enclosures of heavy gauge steel, coated inside and out with
zinc chromate or iron oxide rust inhibiting primer. Finish with gray
enamel. Use manufacturer's standard gray color unless a particular ASA
color is indicated or specified.
G.
Ventilation openings shall be located to permit placing transformer with
two adjacent sides against walls.
H.
Terminal compartment, shall be located below the level of the transformer
winding. Provide access to terminals from front for wall- and floormounted transformers, and from front and bottom for suspended
transformers. Support all terminals.
I.
Manufacturers: General Electric, Westinghouse, or Siemens.
CONTROL TRANSFORMERS
A.
Dry type, integral, self-cooled, two-winding type. Capacity and voltage
ratings as indicated, Class H insulation; NEMA I enclosure except where
installed in control centers or switchboards. Provide secondary fusing.
PART 3 - EXECUTION
3.01
INSTALLATION
A.
Do not install transformers with ventilation openings closer than 12" from
any wall surface. Use flexible conduit for primary and secondary
connections, or other approved mechanical isolation method. Provide a
separate equipment ground conductor in such flexible connections. Do not
attach transformer mounting brackets to walls or structure of other than
poured concrete construction unless approved. Provide Korfund or
equivalent vibration isolators separating the transformer support points
and the supporting structure.
**END OF SECTION**