Document No. 1015-01
Page 1
Howard Industries, Inc.
ISO-9001 Certified
Molded Low-Voltage Bushings
For Pad-Mounted Distribution Transformers
Howard Industries molded low-voltage
bushings are designed for use on fluidfilled pad-mounted distribution transformers, where bushings are mounted
indoors or inside a terminal enclosure.
They are compatible with commonly used
transformer fluids, including mineral oil,
R-Temp®, silicone, and seed-based oils.
The bushings are provided with an
internal copper spade for connection to
low-voltage coil leads and an external
threaded copper stud that will mate with
industry standard low-voltage connectors.
The three-hole mounting configuration is
designed for external attachment and
allows interchangeablity with similarly
designed bushings used on many types
of pad-mounted transformers.
The bushing design incorporates several
improvements intended to prevent fluid
leaks at the tank wall and at the copper-topolymer interface. The tank wall gasket
system features a piloted design to
prevent misalignment during installation
and a positive stop that provides
consistent gasket compression and
prevents overcompression. An internal
gasket seals against leaks at the copper-topolymer interface. Both gaskets are made
of a proprietary compound specifically
suited for transformer use.
Dupont Zytel® HTN high temperature
nylon was chosen as the molding
compound because of its exceptional
mechanical and electrical stability over a
wide range of temperature, humidity, and
environmental extremes. It also exhibits
good flexibility, allowing it to conform to
the tank wall during internal pressure
changes.
Table 1: Electrical Characteristics
Description
Rating
Voltage class
1.2 kV
Basic impulse level (BIL)
30 kV
60 Hz one-minute withstand voltage 10 kV
Max. current, 5/8-inch stud bushing 600 A.
Max. current, 1-inch stud bushing
1500 A.
Document No. 1015-01
Page 2
120°
1.33"
(33.7 mm)
0.70" (17.8 mm)
5/8"-11 UNC-2A
Dia. 0.44"
(11.1 mm)
Mounting
Surface
1.42" (36.0 mm)
Dia. 1.75"
(44.5 mm)
1.88"
(47.8 mm)
Dia. 3.38" (85.7 mm)
Bolt Circle
0.63" (15.9 mm)
1.97"
(50.0 mm)
R 0.50" (12.7 mm)
0.45" (11.4 mm)
1.20" (30.5 mm)
0.80" (20.3 mm)
3.05" (77.5 mm)
Part Number
0061-100389-300
Note: Dimensions for reference only.
Figure 1: 5/8-inch diameter stud with internal spade (pictured on page 1)
120°
1.60"
(40.6 mm)
1.00" (25.4 mm)
Dia. 0.44"
(11.1 mm)
Mounting
Surface
1"-14 UNS-2A
1.42" (36.0 mm)
Dia. 1.75"
(44.5 mm)
Dia. 3.38" (85.7 mm)
Bolt Circle
"B"
2.13"
(54.1 mm)
"A"
0.63" (15.9 mm)
R 0.50" (12.7 mm)
0.45" (11.4 mm)
0.90" (22.9 mm)
0.86" (21.8 mm)
2.66" (67.5 mm)
Part Number
Dim. "A"
Dim. "B"
0061-002000-610
2.04" (51.8 mm)
1.75" (44.5 mm)
0061-002000-620
2.54" (64.5 mm)
2.25" (57.1 mm)
Note: Dimensions for reference only.
Figure 2: 1-inch diameter stud with internal spade
Notes:
1. Tank wall gasket included with bushing.
2. Internal thread available upon request.
3. Leads should be connected to both sides of the internal spade for applications requiring currents of 420 to 600
Amperes for the 5/8-inch stud or 835 to 1500 Amperes for the 1-inch stud.
4. Dimensions are for reference only.
Zytel® is a registered trademark of Dupont. R-Temp® is a registered trademark of Cooper Industries, Inc.
© 2002 Howard Industries, Inc. All rights reserved.
Printed in U.S.A.
Howard Industries, Inc.
Laurel, MS USA 39440
www.howardtransformers.com