Howard Network Transformers - Manual (Page 4)

Copyright © 2010 Howard Industries, Inc.
4
Factory Testing
In addition to numerous quality inspections throughout
the manufacturing process, fi nal tests are conducted on
the completed network transformer to ensure proper func-
tion of all systems. All tests are conducted in accordance
with applicable industry standards. Test equipment is
state-of-the-art and capable of extremely accurate and
reliable test measurements, meeting all the industry loss
measurement standards. All test systems are calibrated
regularly according to industry standards. Calibration of
loss-measuring equipment is NIST traceable.
The following standard and optional production-line tests
are performed. Standard tests are performed on each
completed transformer. Optional tests are performed
upon customer request and at customer expense. Cus-
tomers may arrange to witness factory testing. All tests
will be made in accordance with the latest revisions of
IEEE C57.12.00 Standard General Requirements for
Liquid-Immersed Distribution, Power, and Regulating
Transformers and IEEE C57.12.90 Standard Test Code for
Liquid-Immersed Distribution, Power and Regulating Trans-
formers and Guide for Short Circuit Testing of Distribution
and Power Transformers.
Quality Assurance
Howard employees understand the importance of quality,
particularly as it relates to network transformer applica-
tions. Emphasis on quality begins at design and follows
throughout the manufacturing and delivery processes.
Only the highest quality components and materials are
used in Howard network transformers. Attention to detail
during manufacture, and careful inspection and testing
ensure that a high level of quality is maintained.
Howard’s quality management system is designed to
ensure that all of the company’s products and services
meet or exceed our customers’ requirements and is certi-
fi ed by DQS-UL as being compliant with ISO-9001:2008.
The ISO-9001:2008 standard covers design, manufactur-
ing, and servicing systems, and is the most stringent and
comprehensive standard in the internationally recognized
ISO-9000 series of quality standards.
Network Transformer
94-10
Howard Industries, Inc.
Laurel, MS 39440
www.howardtransformers.com
Catalog Section 94-10
Network Transformers
Issued: April 9, 2010
Production-Line Tests
Standard
Test
Optional
Test
Winding resistance •
Winding insulation resistance (Megger) •
Ratio •
Polarity and phase relation •
Insulation power factor •
No-load losses and excitation current •
Impedance voltage and load losses •
Zero-phase sequence impedence
voltage
•
Temperature rise •
Low frequency dielectric tests •
Applied potential •
Induced potential •
Lightning impulse •
Front-of-wave impulse •
Audible sound level •
Leak test •
Partial discharge (RIV) •
ANSI impulse test •