Tyco Fire Product Gem F978, Instruction Manual, Page: 4 / 12

Operational Sensitivity Criteria. For
proper operational sensitivity, the
F978 Sprinklers must be installed be-
neath solid ceilings having a smooth
flat or textured surface and in accord-
ance with Figure A.
The F978 Sprinklers must NOT be
used above or below open-gridded
type suspended ceilings; beneath sof-
fits or beams having a depth of more
than 4 inches (101,6 mm); and, with
beams, joists, or ducts having a height
of more than 3 inches (76,2 mm) lo-
cated within the sprinkler coverage ar-
eas.
NOTE
Beams having a height of more
than 3 inches (76,2 mm) may be
located with their centerlines
along the boundaries separating
adjacent sprinkler coverage ar-
eas.
It is recommended that as part of the
sprinkler system design, the designer
review the dwelling plans and, where
appropriate, advise the owner or his
representative as to the following.
I.
Lintels of at least 3 inches (76,2
mm) in height and preferably 8
inches (203,2 mm) should be used
over all passageways from one
space to another, in order to reduce
the possibility of sprinkler opera-
tions outside of the fire area.
II.
Beams of at least 3 inches (76,2
mm) in height should be used to
border each of 5 or more adjoining
areas of F978 Sprinkler coverage
(within the same compartment), in
order to decrease the time to first
sprinkler operation as well as to
reduce the possibility of multiple
sprinkler operations.
Cold Soldering Criteria. Figures E
and F provide the minimum spacing
requirements necessary for prevent-
ing the wetting (i.e., cold soldering) of
the heat responsive element (Bulb) of
a non-operated F978 Sprinkler, which
is adjacent to one which has operated.
Heat Source Criteria. Refer to NFPA
13D or NFPA 13R for the requirements
relating to preventing the possible re-
lease of an F978 heat responsive ele-
ment (Bulb), due to exposure to heat
sources other than abnormal fire.
—4—
FIGURE E
SPACING RULES UNDER LEVEL CEILINGS
Figure E-1 (Plan View) Figure E-2 (Plan View)
Figure E-3 (Plan View) Figure E-4 (Plan View)
Figure E-5 (Plan View)
Figure E-6 (Plan View)
Figure E-7 (Plan View)
Figure E-8 (Plan View) Figure E-9 (Elevation View)
S = THE LENGTH OF THE COVERAGE AREA BEING HYDRAULICALLY
CALCULATED (REF. TABLE A).
OBSOLETE