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Product information
Introduction
Service Information MN230001EN covers the maintenance
instructions for Eaton's Cooper Power™ series Type NR
electrically-operated, single-phase, oil switches. This
includes their general description, operating principles and
instructions for periodic inspection and shop repairs. Service
parts lists, keyed to exploded-view drawings of the switch,
are included at the back of the manual.
Type NR oil switches are single-phase, electrically-operated
with a quick-close, quick-open mechanism which also
provides the switch with close-and-latch capability.
The switches are electrically operated. The standard actuator
can be operated by any three-wire control device employing
a set of SPDT contacts.
Read this manual first
Read and understand the contents of this manual and follow
all locally approved procedures and safety practices before
installing or operating this equipment.
Additional information
These instructions do not claim to cover all details or
variations in the equipment, procedures, or process
described, nor to provide directions for meeting every
possible contingency during installation, operation, or
maintenance. For additional information, contact your Eaton
representative.
Acceptance and initial inspection
Each Type NR oil switch is completely assembled, tested,
and inspected at the factory. It is carefully calibrated,
adjusted and in good condition when accepted by the
carrier for shipment.
Upon receipt, inspect the carton for signs of damage.
Unpack the switch and inspect it thoroughly for damage
incurred during shipment. If damage is discovered, file a
claim with the carrier immediately.
Handling and storage
Be careful during handling and storage of the switch to min-
imize the possibility of damage. If the switch is to be stored
for any length of time prior to installation, provide a clean,
dry storage area.
Standards
Type NR oil switches are designed and tested in accordance
with IEEE Std C37 .66™-2005 standard.
Quality standards
ISO 9001 certified quality management system
Description of operation
With the main switch contacts closed, energizing the
opening circuit will operate the actuator motor to release
a toggle which allows the preloaded opening springs to
snap open the switch contacts and load the closing spring.
It also drives the cam to position the selector switch for
a closing operation and interrupts the opening circuit to
stop the motor. The opening circuit must remain energized
for at least 4.0 seconds for the actuator to perform these
functions.
With the main switch contacts open, energizing the
closing circuit will operate the actuator motor to allow the
preloaded closing spring to snap closed the switch contacts
and load the opening spring. It also drives the cam to
position the selector switch for an opening operation and
interrupts the closing circuit to stop the motor. The closing
circuit must remain energized for at least 0.5 seconds for
the actuator to perform these functions.
A holding switch accessory installation in the actuator
reduces to one second the minimum time the control must
be energized to effect an opening or closing operation.
TYPE NR OIL SWITCH MAINTENANCE INSTRUCTIONS MN230001EN February 2016
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