Hitachi SM 6145, Installation Operation & Maintenance

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STS USASecondary Surge Suppressors USSP)
Copyright SM 6145, Rev. 23, March 2019 1-2
positive terminal to the negative terminal). On track circuit models, this same USG-A
Low Voltage Arrester is wired across the track leads.
High voltage arresters (N451552-0201) are installed between a ground post and each of
the battery or track circuit lead wires. AC line arresters (N1451552-0401) are installed
across the AC power wires on the AC Line USSP models. Refer to Figure 1-2 for the
various arrester/terminal arrangements and to Service Manual 6108 for further
information on the USG-A arresters. Figure 1-2 shows the positions of the various USG-
A arresters on the USSP models.
CAUTION
The USG-A Low Voltage Arrester (N451552-0101) is a
varistor filled gap arrester designed to be used in a Line-to-
Line application. These are NOT to be used in a Line-to-
Ground application. The USG-A High Voltage Arrester
(N451552-0201) is a true air gap arrester and is designed to
be used in Line-to-Ground applications.
1 . 2 Specifications
1.2.1 Physical/Mechanical (Typical Unit)
Length (including mounting brackets): 8 7/8 inches
Width: 3 ¾ inches
Depth (including terminals): 3 ¾ inches
Weight (with 3 arresters): 2.25 lbs.
Mounting: Two flat brackets, hole centers 7 ½ inches apart, for ¼
inch diameter fasteners.
Temperature Environment: -40° F to +158° F (-40° C to +70° C)
1.2.2 Electrical
For electrical specifications of the USSP models, refer to Table 1-1.