2
Product Description
The Model N252 EC Pendent are Control Mode Specific
Application Extended Coverage Sprinklers for Storage
Applications. This includes protection of the storage and
display of Class I through IV commodities encapsulated or
unencapsulated, cartoned unexpanded plastics. The Model
N252 EC sprinklers offer maximum coverage areas up to 14 ft
by 14 ft (196 ft
2
) as compared to ESFR or Standard Coverage
Control Mode or Control Mode Specific Application sprinklers
with maximum coverage of 100 ft
2
(9 m
2
). This offers the
advantage of decreasing the number of required sprinklers,
reducing labor and material costs. The Model N252 EC Pendent
Control Mode Specific Application Sprinklers is designed for
use in ceiling only sprinkler systems with no in-rack sprinklers
required.
Operation
The Reliable Model N252 Extended Coverage Pendent
Control Mode Specific Application Storage Sprinklers utilize a
levered fusible alloy solder link. When the rated temperature
is reached, the solder melts and the two link halves separate
allowing sprinkler to operate and water to flow.
FM Approved for the following:
1. Application:
These FM Approved extended coverage
CMSA automatic sprinklers may be used to protect Class
1 through 4, cartoned unexpanded plastic commodities
under ceilings up to and including 35 ft (10.7 m) high. They
may be used to protect any storage arrangement outlined
in Data Sheet 8-9, however portable racks must meet the
guidelines required to be considered open-frame racks.
Maintain a minimum clearance of 3 ft (0.9 m) between the
top of storage and the sprinkler deflector.
Temperature Rating:
The Reliable Model N252 EC
sprinkler is available in nominal temperature ratings of either
165 °F (70 °C) or 212 °F (100 °C). Use the nominally rated
165 °F (70 °C) sprinkler for all acceptable applications
unless the ambient temperature of the protected occupancy
requires the temperature rating to be 212 °F (100 °C).
2. Hydraulic Design:
Base the design for these automatic
sprinklers as follows:
Solid-Piled, Palletized, Shelf or Bin-Box and Open-
Frame Racks:
See table 1.
Storage Racks Equipped With Solid Shelves:
Base the
design of the ceiling sprinkler system as outlined above
for open-frame racks, however base the need for, as well
as the design of, in-rack sprinkler protection the same
as what is required for K16.8 (K240) CMSA sprinklers.
Shape of Operating Area:
Base the shape of the operating
area on a 1.2 shape factor for ceiling slopes up to 5° or a
1.4 shape factor for ceilings having a higher slope (up to
10° maximum).
3. System Type:
Wet-pipe sprinkler systems or pre-action
sprinkler systems, whose sprinkler protection design can
be based on the equivalent of a wet-pipe system, are
acceptable.
4. Sprinkler Spacing:
The minimum and maximum linear
distances between sprinklers are 10 ft (3.1 m) and 14 ft
(4.2 m) respectively for ceiling heights up to and including
30 ft (9.0 m). For ceiling heights over 30 ft (9.0 m) and up to
35 ft (10.7 m) the maximum linear spacing of the sprinkler
is reduced to 12 ft (3.6 m). The minimum and maximum
area of coverage per sprinkler is 100 ft
2
(9 m
2
) and 196 ft
2
(18 m
2
) respectively for ceiling heights up to and including
30 ft (9.0 m). For ceiling heights over 30 ft (9.0 m) and up to
35 ft (10.7 m) the maximum area spacing of the sprinkler is
reduced to 144 ft
2
(13.5 m
2
).
5. Sprinkler Location from Walls:
Locate the
automatic sprinklers with respect to walls,
measured perpendicular to the wall, as follows:
Minimum Horizontal Distance: 4” (100 mm).
Maximum Horizontal Distance unless indicated otherwise
in either the occupancy-specific data sheet or the Approval
Guide:
a. Wall Angle Greater Than 90°: 7 ft (2.1 m) for
ceilings up to 30 ft (9.0 m) high or 6 ft (1.8 m) for
ceilings over 30 ft (9.0 m) and up to 35 ft (10.7 m)
high.
b. Wall Angle Equal to or Less Than 90°: 10 ft (3.0 m)
for ceilings up to 30 ft (9.0 m) high or 8 ft (2.4 m)
for ceilings over 30 ft (9.0 m) and up to 35 ft
(10.7 m) high.
6.
Sprinkler Location from Ceilings:
Locate the automatic
sprinklers with respect to ceilings in accordance with Data
Sheet 2-0. However, the minimum vertical distance below a
ceiling can be reduced to 2” (50 mm) for smooth ceilings or
4” (100 mm) for non smooth ceilings.
7.
Obstructions:
Use the obstruction guidelines outlined
in D.S. 2-0 for extended coverage automatic sprinklers
in regards to the umbrella pattern. In addition, use the
obstruction guidelines outlined in D.S. 2-0 for pendent
automatic sprinklers in regards to obstructions located
below the automatic sprinkler, except that an individual
object up to a maximum width of 1.25 in; (31 mm) can be
tolerated less than 12” (300 mm) horizontally away from
the sprinkler as long as the object is located at least16”
(400 mm) vertically below the sprinkler. All other design
details should be in accordance with Data Sheet 8-9. All
other installation details should be in accordance with Data
Sheet 2-0.
8.
FM Global considers this a “Quick Response” Extended
Coverage Sprinkler for use in Data Sheet 8-9.
9.
For installations governed by NFPA #13 (2013)
, the
N252EC fire sprinkler meets the definition of Control Mode
Specific Application (CMSA) Sprinklers and is approved
for installation under chapter 21. Section 3.6.4.1. Section
8.11.1.1 states that CMSA sprinklers shall be installed
in accordance with Section 8.5 and the manufacturer’s
installation instructions.
.
