Howard HI-102 Overhead Transformer - Manual (Page 18)

Document 2.4.95, Revision 0
May. 2013
18
Fluid-Filled Overhead Distribution Transformers
general guide for operation of the Magnex Interrupt-
er. Personnel should read and follow Cooper Power
Systems Magnex Interrupter Installation Instructions
S240-34-1.
The operating handle is located on the side of the
transformer tank and is designed to be operated
with a live-line tool (hot stick), as follows.
− To open the interrupter, rotate the handle
upward in a counterclockwise direction,
until the spring-loaded contacts open and
the handle is in the OPEN position.
− To close the interrupter, rotate the handle
downward in a clockwise direction, until the
handle is against the physical stop in the
CLOSED position. When in the CLOSED po-
sition, the interrupter will operate automati-
cally due to an over-current condition or rise
in oil temperature.
− To reset the interrupter after it has tripped,
rotate the handle upward in a counterclock-
wise direction to the OPEN position, and
then downward in a clockwise direction,
until the handle is against the physical stop
in the CLOSED position.
An optional trip indicator is available, consisting of
an indicator lens which appears orange when the
interrupter is in the TRIPPED position.
Some Magnex Interrupters are supplied with an
optional emergency overload setting. The emergency
overload will allow approximately 30% overload be-
fore tripping. Using a live-line tool (hot stick), operate
the emergency overload as follows.
− To enable emergency overload, rotate the handle
upward in a counterclockwise direction, until the
handle is in the OPEN position. Next, turn the
emergency overload lever counterclockwise to
the EO position. Then rotate the handle down-
ward in a clockwise direction, until the handle is
in the CLOSED position.
− To disable emergency overload, rotate the
handle upward in a counterclockwise direction,
until the handle is in the OPEN position. Next,
turn the emergency overload lever clockwise to
the NORMAL position. Then rotate the handle
downward in a clockwise direction, until the
handle is in the CLOSED position.
The Magnex Interrupter does not provide a visible
disconnect and should not be relied on as the sole
indication that the transformer secondary terminals
are de-energized.
▲
! WARNING
FAILURE TO FOLLOW THE INSTRUCTIONS
BELOW COULD RESULT IN DEATH OR SERIOUS
PERSONAL INJURY, AND COULD ALSO RESULT
IN DAMAGE TO THE EQUIPMENT.
• Do not rely solely on the Magnex interrupter
to de-energize the transformer secondary.
Always ground the secondary terminals
before performing work.
• Operate the Magnex Interrupter with a live-
line tool (hot stick or shotgun stick). Never
operate by hand.
• Do not operate the Magnex Interrupter if
there is evidence of tank distress or leaking.
• The handle must be rotated fully against the
stop in the CLOSED position.
Other Switching and Protective Devices
Overhead transformers may be provided with
switching and protective devices not discussed
in these instructions. In such cases, contact the
Howard Industries Transformer Division or the device
manufacturer for instructions.