Table of Contents
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1.
INTRODUCTION
This manual covers the PV-250 Plug-In AC Vane Relay used for track circuit
applications. Since the relay is a two-element AC vane type, it must be provided with
the appropriate equipment to provide the adequate phase displacement between the
local and control (track windings). The earlier and later design relays have the same
operating characteristics and fit into the same mounting base. The design of the PV-
250 Relay conforms to all applicable AREMA specifications.
1.1. Shock Indicators
Any relay showing Shock Indicator activation should be
serviced before placing the relay into service. Failure to
assure proper function of this relay may result in severe
personal injury or death.
The shock indicator shows red when the relay was subjected to shock in excess of safe
levels (e.g., dropped) during shipment or transport. This is an indication that the relay
may have mechanical damage and may not meet electrical specifications.
The relay should be opened and visually inspected for damage (i.e., kinked springs).
Mechanical settings should be checked, re-calibrated, and tested according to
specifications by a qualified individual.
1.2. Description
1.2.1. General
The relay is factory calibrated to operate across a wide environmental range. All moving
parts are enclosed in a sturdy, transparent, dust and moisture-resistant cover. To
ensure the relay is inserted in its proper mounting base, all relays have indexing pins.
Relays lock securely in the plug-in position.
1.2.2. Coils
This relay uses single-wound coil for the control element and a local element that
presents the impedance to meet the specifications of Table 3-1, Table 3-2, and Table
3-3.
1.2.3. Contacts
Contacts of the PV-250 relay are standard low-voltage silver-to-silver impregnated
carbon front and silver-to-silver back. See Figure 4-2 for an illustration of the contact
block assembly.
Copyright 2019
WARNING
SM 4574F, Rev. 4, March 2019
PV-250 Track Relay
1-1
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