ACME ELECTRIC
•
MILWAUKEE, WI
•
800.334.5214
•
acmetransformer.com
137
GENERAL
ELECTRICAL CONNECTION DIAGRAMS
ACME
®
TR NSF RMER
™
SPECIFIC TIONS
1.0 Dry Type Transformers:
1.0.0
The following information should be utilized only by
trained technical personnel. If you need assistance,
please contact Acme’s Technical Services
Department at 800-334-5214.
1.0.1
Provide dry type, enclosed, and ventilated
transformers as indicated and specified herein.
Transformers must be Acme or approved equal.
Transformers must be UL listed for non-sinusoidal
current loads of a specified K Factor (UL Standard
1561), CSA certified and labeled as such.
1.0.2
For sizes 15 kVA and larger, low voltage dry
transformers will be ventilated type, incorporating a
220 degree C insulation system and designed not to
exceed 150 degree C temperature rise above a 40
degree C ambient under full load conditions. Taps will
be provided on the primary side of the transformer.
There will be 2, 2.5% taps above normal full capacity
and 4, 2.5% taps below normal full capacity.
Alternate 1:
115 degree C rise Transformers shall
incorporate a 220 degree C insulation system and
be designed not to exceed 80 degree C temperature
rise above a 40 degree C ambient under full load
conditions. In addition, the transformer shall have the
ability to carry a continuous 15% overload without
exceeding a 150 degree C rise above ambient.
Alternate 2:
80 degree C rise Transformers shall
incorporate a 220 degree C insulation system and
be designed not to exceed 80 degree C temperature
rise above a 40 degree C ambient under full load
conditions. In addition, the transformer shall have the
ability to carry a continuous 30% overload without
exceeding a 150 degree C rise above ambient.
1.0.3
Transformers shall incorporate an electrostatic shield
for the attenuation of voltage spikes, line noise, and
transients.
1.0.4
Transformers must be designed to handle non-
linear loads and the adverse effects of harmonics.
Transformer coils will be wound with foil to minimize
the heating effects caused by harmonic currents.
1.0.5
Transformers must be able to power non-linear loads
with a K-Factor as high as 20.
1.0.6
Transformers must operate at audible sound levels
below NEMA ST-20. Sound levels will not exceed the
following:
30 - 50 kVA 45 db*
51 - 150 kVA 50 db*
151 - 300 kVA 55 db*
301 - 500 kVA 60 db*
* Sound levels are based on transformers with a K-Factor of
4 and a temperature rise of 150 degrees centigrade.
Enclosed, ventilated transformers must incorporate
vibration dampening pads in their construction,
located between the transformer core and coil
assembly and the transformer case. External vibration
dampening pads will not be used on enclosed,
ventilated designs as they tend to increase audible
noise. Transformers 15 kVA and larger shall be floor
mounted on a concrete pad. All connections to the
transformer will be made by means of flexible metallic
conduit.
1.0.7
Transformers shall incorporate a neutral conductor
sized at 2 times rated phase current. Transformer
cases shall be grounded per the National Electric
Code.
1.0.8
Transformers shall be 60 Hz, 480 or 600 volts delta
primary, 208Y/120 volt secondary. kVA rating as
indicated. Contractor to provide all necessary lugs for
all transformers. Transformer enclosures shall be
Type 2 and UL-3R listed with the addition of a weather
shield.
1.0.9
Complete shop drawings must be submitted for
approval on all dry type transformers.
1.0.10
Typical performance data must be submitted for
approval on all transformers. Factory tests must be
made in accordance with the latest revisions of ANSI
Test Code C57.12.91 for Dry Type Transformers.
Performance data must contain but not be limited to:
(a)
No load losses.
(b)
Full load losses.
(c)
Polarity and phase rotation.
(d)
Impedance at reference temperature.
(e)
Efficiencies at 25, 75, 50 and 100% load.
(f)
Regulation at 100% and 80% power factor.
(g)
Audible sound level.
(h)
Insulation class and rated temperature rise.
(i)
Dimensions and weight.
(j)
Applied potential test.
(k)
Induced potential test.
(l)
Excitation current.
(m)
IR, IX, and IZ percentages.
(n)
Reference and ambient temperature.
1.0.11
Warranty: Transformers must be warranted against
defects in materials, workmanship and performance
for ten years from date of manufacture.
Specification Guide for Non-Linear Load
Isolation
®
Transformers
