Wayside Products
Ansaldo STS USA
(Formerly known as Union Switch & Signal)
RSE-3H2
Rev. 1-04
USGA Lightning Arresters
USG-A Lightning Arresters reduce the chances of
damage to electrical and electronic equipment
from lightning strokes. As a result, they help
minimize service disruptions and equipment
down-time. These units incorporate the latest in
lightning arrester technology, and are available in
several models to satisfy most applications,
including high voltage, low voltage and ac line.
General Description
USG-A Lightning arresters are designed to limit surge
voltage transients on electrical equipment below
breakdown voltage, and minimize surge current
through the equipment. They are provided as
separate units, or are mounted on a terminal block.
Typical applications are shown in the diagram.
The standard low-voltage arrester is a varistor-filled
gap arrester. The varistor material is mounted in
parallel with a high durability air gap formed by the
separation of two brass disks. Static charges are bled
off by the varistor, and fast-rising transients are
immediately clipped with a minimum of overshoot.
ASTS USA’s low-voltage green arrester is provided
for those stringent applications where the minimum
possible clamping voltage must be assured. Each
green arrester is meticulously tested for this purpose.
As shown in the Specifications, the green arrester
clamps a 1000 volt dynamic surge to 250 - 450 volts
peak. This is typically 100 volts lower than a blue
arrester subjected to the same dynamic test.
The high-voltage arrester is a true air-gap arrester.
The gap is physically held by a Teflon spacer and is in
series with a varistor, making it a current-limiting gap.
This arrangement is in parallel with the gap formed by
the separation of the brass disks.
USG-A Lightning Arresters are equipped with a highstrength, clear Lexan® cover that permits visual
inspection of internal components, and contains the
explosive effects of heavy surges. Part numbers are
stenciled and color-coded for quick identification of
different units.
Advantages
•
•
•
•
State-of-the-art lightning protection
Models for high and low voltage dc, ac line
Easy to inspect
“Green” arrester for special applications
Specifications
Operating Voltages:
Low Voltage (blue and
green): 32 Vdc, 25 Vac
High Voltage (red): 250
Vdc, 175 Vac
AC Line (yellow): 140 Vac
Breakdown Voltage:
Low Voltage (blue and
green): 75-200 Vdc, 50100 Vac (60 Hz)
High Voltage (red): 5003000 Vdc, 350-950 Vac
Resistance:
Low Voltage (blue and
green): >103 ohms @ 32
Vdc
High Voltage (red): >109
ohms @ 100 Vdc
AC Line (yellow):
>5 x 103 ohms @ 120 Vac
Dynam. Test Green Arr:
Dynamic wavefront: 1000
VPEAK 10 kV /microsec.
rise rate
Peak V: 250 to 450 VPEAK
To order, call 1-800-652-7276
e-mail: orders@ansaldo-sts.us
www.ansaldo-sts.com
RSE-3H2, p. 1
Ansaldo STS USA
USGA Lightning Arresters
(Formerly known as Union Switch & Signal)
RSE-3H2
Rev. 1-04
Ordering and Additional Information
•
•
Refer to ordering tabulation for standard USG-A
arrester units, terminal block kits and block unit
only.
Order No.
N451552-0101
N451552-0103
N451552-0201
N451552-0401
X451552-0301
X451552-0302
X451552-0306
X451552-0308
N451552-0303
•
Order terminal block and mounting hardware
separately for low voltage green arrester.
Request ASTS USA Service Manual SM-6108 for
additional information on USG-A Arresters.
USG-A Arrester Units, Kits and Terminal Block
Arrester Unit
Type
Arrester Color
w/Term. Block
X
Low Volt.
Blue
-X
Low Volt.
Green
-X
High Volt.
Red
-AC Line
Yellow
-X
X
Low Volt.
Blue
X
X
High Volt.
Red
X
AC Line
Yellow
X
X
X
High Volt.
Red
X
Terminal Board for Lightning Arresters (except green arrester)
Typical Circuit Applications
Terminal Block Assembly
RSE-3H2, p. 2
w/Mtg. Hardw.
----X
X
X
X