Type VSA12, VSA16 and VSA20/800 maintenance instructions
1 MAINTENANCE INSTRUCTIONS MN280064EN October 2017
Introduction
Service Information MN280064EN covers the maintenance
instructions for the type VSA electronically controlled, three-
phase, vacuum recloser. The manual includes a general
description of the recloser and its operation and instructions
for periodic inspection, testing and shop repairs. Keyed
service parts exploded-view drawings of the unit, along with
ordering information are included at the back of the manual.
Description and operation
The VSA12, VSA16 and VSA20/800 three-phase reclosers
feature vacuum interruption and air insulation. Current
interruption takes place in the rugged vacuum interrupter
assemblies which are suspended from the recloser cover
by insulating supports, as shown in Figure 1. The moving
contacts, located in each interrupter assembly, driven by the
recloser operating mechanism, close or open the circuit.
Interruption takes place within two and one-half cycles,
while utilizing a contact stroke of one-half inch.
Recloser tripping and closing are initiated by signals from
the recloser control unit. When current in excess of the
programmed minimum trip level is detected, on any phase
or phases, the recloser control initiates a trip signal which
energizes a solenoid in the operating mechanism of the
recloser. When actuated, this solenoid trips the opening
springs, which opens the interrupter contacts.
Closing springs provide the force required to close the
vacuum interrupters, as well as the force required to charge
the opening springs. A 240 Vac motor charges the closing
springs through a multi-stage gear drive. When 240 Vac is
present, the motor is automatically operated to keep the
closing springs in a charged state. To close the recloser the
control initiates a signal which energizes a solenoid in the
recloser operating mechanism. Once actuated the solenoid
releases the closing springs, which close the vacuum
interrupters and charge the opening springs. Therefore a
sequence of Open-Close-Open is available after loss of 240
Vdc power.
An external 240 Vac source is required to operate the drive
motor. A battery, in the electronic control, supplies the 24
Vdc tripping and closing power.
Recloser tripping employs stored spring energy. The stored
spring energy is released, to open the recloser, when the
trip solenoid is actuated by the 24 Vdc trip signal. The 24
Vdc trip signal is originated at the recloser control. The 240
Vac supply is not required to trip the recloser.
A totally manual closing operation can be accomplished
even during loss of motor power and with the closing
springs discharged. A hand crank can be applied to the
motor to charge the closing springs. Once charged, the
closing springs can be released either from inside or from
below the operator mechanism cabinet. As with electrical
operations, the opening springs are charged by release of
the closing springs, so even a manually closed unit has
energy stored for a trip operation.
Major parts and assemblies of the VSA recloser are shown
in Figures 1 and 2. Being aware of the location of these
components and their part in the operation of the recloser
will give a quicker and clearer understanding of the recloser
maintenance and repair procedures that follow.
Figure 1. Type VSA recloser with side panels removed
To Next Page
Loading...
Need help?
General
