Richards 137NP, Инструкция по эксплуатации, Страница: 42 / 53

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O. Manual Cutoff Switch
The manual cutoff switch (see Figure 18), located on the right side of mechanism and
actuated by a cam on manual operating shaft, opens the “closing” circuit when the manual
handle is rotated to the “open” or “closed” position, thus preventing the protector from
attempting to reclose with the handle in either of these positions. When the handle is rotated
to the “closed” position, the breaker will be closed but will trip free from the manual handle
if the trip coil is energized or the trip latch is released. When the handle is in the “automatic”
position, the protector will perform its normal automatic functions.
The contacts of this switch should be examined periodically. If necessary, dress contacts
with a fine file in high spots only, do not file to bottom of pits
P. Closing Linkage
The main closing linkage is contained in the main mechanism frame.
The complete operating mechanism can be removed from the breaker by disconnecting the
control leads, and removing the two bolts on each side of the main mechanism frame, which
hold this frame to the breaker frame. This operation may be performed either with the motor,
gear assembly and trip mechanism in place, or with any of these parts removed.
CAUTION: Breaker must first be open.
VI. THE ENCLOSURE
The 137NP network protector (see page iii) is provided with a submersible enclosure. All cases
are provided with a cover which may be hinged from either side and an external manual
operating handle which should always be mounted on the side opposite the cover hinges so as to
be accessible when the cover is open. If the enclosure is opened before the protector is mounted
in its final location, be sure to secure the top of the enclosure to a solid support to prevent the
protector from tipping forward when the unit is rolled forward.
The cover is provided with a gasket for making a watertight joint with the case. Gasket and case
surfaces should be cleaned to insure a tight joint. Before closing the cover, it is advisable to
cover the gasket surfaces with a thorough coating of flaked graphite or water pump grease for
cork and flaked graphite or talc for Corprene. On quick opening boxes with rubber gaskets use
talc. This procedure should be followed each time the cover is closed. The cover should be
clamped against the case with the clamping arrangement provided by tightening the bolts
gradually to insure an even distribution of pressure on the gasket.
All pipe thread fittings including pipe plugs, inspection window holders and pressure test valves,
if removed, should be replaced by applying Glyptal or white lead to threads to insure a tight
joint. All wiping sleeve cable bushing nuts, before being replaces, should be coated with a
mixture of graphite and oil so that they can be removed or tightened easily.