Acme Catalog

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Specifications G e n e r a l
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1.0.10 Transformers must operate at audible sound levels below ANSI/NEMA Standard ST-20. Sound levels will not exceed the
following:
Up to 9 kVA 40 db
10 - 50 kVA 45 db
51 - 150 kVA 50 db
1.0.11 Transformer enclosures shall be grounded per the National Electric Code.
1.0.12 Complete shop drawings must be submitted for approval on all Dry Type Transformers.
1.0.13 Typical performance data must be submitted for approval on all transformers. Factory tests must be made in accor-
dance 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, 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.
1.0.14 Warranty: Transformer 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
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*