(2) For engines above 600 rpm and under 1200
(1) For engines under 600 rpm (for any size)
hp (except (3) below).
and over 1200 hp (for any speed).
(a) No vibration isolation of the engine as-
(a) No vibration isolation of the engine as-
sembly is required if there is no category 1 area
sembly is required if there is no category 1 area
(table 3-2 in the N&V manual) within 300 ft., or no
(table 3-2 in N&V manual) within a horizontal dis-
category 2 or 3 area within 150 ft., or no category 4
tance of 500 ft., or no category 2 or 3 area within
or 5 area within 75 ft. of the engine base. It is good
250 ft., or no category 4 or 5 area within 150 ft. of
practice, nevertheless, to give the engine base its
the engine base. It is good practice, nevertheless,
own footings, separated from the footings of the
to give the engine base its own footings, separated
generator room, with a structural break between
from the footings of the generator room, with a
the floor slab or floor grille of the generator room
structural break between the floor slab or floor
and the engine base. (It is assumed throughout this
grille of the generator room and the engine base.
schedule that feelable vibration is acceptable in
(It is assumed throughout this schedule that
category 6 areas. If this is not an acceptable as-
feelable vibration is acceptable in category 6 areas.
If this is not an acceptable assumption, category 6
sumption, category 6 should be considered along
with categories 4 and 5.)
should be considered along with categories 4 and
(b) For distances closer than those listed in
5.)
(a) above, for the indicated categories, the engine
(b) For distances closer than those listed in
(a) above, for the indicated categories, the engine
base should be supported on steel spring vibration
isolation mounts that have a static deflection of at
base should be supported on steel spring vibration
isolation mounts that have a static deflection of at
least 2 in. for engine speeds of 600 to 1200 rpm or
least 1 in. for engine speeds above 600 rpm or 2 in.
at least 1 in. for engine speeds above 1200 rpm.
(c) The steel springs of (b) above should
for engine speeds of 301 to 600 rpm or at least 4 in.
rest on pads of ribbed or waffle-pattern neoprene if
for engine speeds of 200 to 300 rpm.
(c) The steel springs of (b) above should
the engine assembly is located within 200 ft. of a
rest on pads of ribbed or waffle-pattern neoprene if
category 1 area or within 100 ft. of a category 2 or
the engine assembly is located within 200 ft. of a
3 area or within 50 ft. of a category 4 or 5 area. Pad
details are given in paragraph d(1) below.
catagory 1 are or within 100 ft. of a category 2 or 3
(3) For engines above 1200 rpm and under 400
area or within 50 ft. of a category 4 or 5 are. Pad
hp. A concrete inertia block is not required for this
details are given in paragraph d(1) below.
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