Correspondence •
FAX TRANSN
„a.... 4
Date
rEB. 1 S'1
Number of pages including cover sheet
To: Bear Electric From: Gary Noble
Co: Co: City of Tigard
Fax #: 503) 61 - 1 0 % Fax #: (503) 624 -3681
Ph #: (503) 718 -1446
SUBJECT: Green Office Building 11560 SW 67 Ave.
pe.p4w0 11- EL-C. 200b - 00018
I conducted an inspection at 11560 SW 67 Ave. on February 9, 2006.
This inspection was for the Voice /Data installation done by Communications
Installation Services. During the inspection process, I noticed that your company had
installed type NM cable exposed on the ceiling of the Suites involved.
I am writing you my concerns about the applicability of this method of wiring so you
are not unaware of the code as I read it. The installation as it stands is a violation of
Art. 334.10(3) of the National Electrical Code.
The wording "Cables shall be concealed within walls, floors, or ceilings that provide a
thermal barrier of material that has at least a 15- minute finish rating as identified in
listing of fire -rated assemblies" is the language I am referring to.
When you call for rough inspection, I will write this correction. I regret that so much
work has taken place at this time, and hope you can select another method that will be
code compliant.
Gary Noble
Senior Electrical Inspector, City of Tigard
I:1ENGIFAX.DOT
An inspection was conducted by me at 11560 SW 67 Ave. on February 9, 2006.
This inspection was for the Voice/Data installation by made by Communications
Installation Services.
During the inspection process, I noticed that your company had installed type NM cable
exposed on the ceiling of the Suites involved.
This is a violation of Art. 334.10(3) of the National Electrical Code.
The wording "Cables shall be concealed within walls, floors, or ceilings that provide a
thermal barrier of material that has at least a 15- minute finish rating as identified in
listing of fire -rated assemblies" is where the violation takes place.
Please be informed that I will write this correction when an inspection for electrical
rough -in is requested.
I conducted an inspection at 11560 SW 67 Ave. on February 9, 2006.
This inspection was for the Voice /Data installation done by Communications Installation
Services. During the inspection process, I noticed that your company had installed type NM
cable exposed on the ceiling of the Suites involved.
I am writing you my concerns about the applicability of this method of wiring so you are not
unaware of the code as I read it. The installation as it stands is a violation of Art. 334.10(3)
of the National Electrical Code.
The wording "Cables shall be concealed within walls, floors, or ceilings that provide a
thermal barrier of material that has at least a 15- minute finish rating as identified in listing of
fire -rated assemblies" is the language I am referring to.
When you call for rough inspection, I will write this correction. I regret that so much work
has taken place at this time, and hope you can select another method that will be code
compliant.
• ARTICLE 334 — NONMETALLIC-SHEATHED CABLE: TYPES NM, NMC, AND NMS 334.15
II. Installation (2) Exposed in dropped or suspended ceilings in other
) 334.10 Uses Perm T ype NM, Type NMC, and than one- and two-family and multifamily dwellings
Type NMS cables shall be permitted to be used in the (3) As service - entrance cable
following: (4) In commercial garages having hazardous (classified)
(1) One- and two - family dwellings. locations as defined in 511.3
(2) Multifamily dwellings permitted to be of Types III, IV, (5) In theaters and similar locations, except where permit-
and V construction except as prohibited in 334.12. ted in S 18.4(B)
(3) Other structures permitted to be of Types III, IV, and V (6) In motion picture studios
construction except as prohibited in 334.12. Cables (7) In storage battery rooms
shall be concealed within walls, floors, or ceilings that (8) In hoistways or on elevators or escalators
provide a thermal barrier of material that has at least a (9) Embedded in poured cement, concrete, or aggregate
I5- minute finish rating as identified in listings of fire- (10) In hazardous (classified) locations, except where per-
rated assemblies. mitted by the following:
FPN No. 1: Types of building construction and occupancy a. 501.10(B)(3)
classifications are defined in NFPA 220 -1999, Standard on b. 502.10(B)(3)
Tvpes of Building Construction, or the applicable building C. 504.20
code, or both.
FPN No. 2: See Annex E for determination of building (B) Types NM and NMS. Types NM and NMS cables
types [NFPA 220, Table 3 -11. shall not be used under the following conditions or in the
(4) Cable trays in structures permitted to be Types III, IV, following locations:
or V where the cables are identified for the use. (1) Where exposed to corrosive fumes or vapors
FPN: See 310.10 for temperature limitation of conductors. (2) Where embedded in masonry, concrete, adobe, fill, or
plaster
(A) Type NM. Type NM cable shall be permitted as follows: (3) In a shallow chase in masonry, concrete, or adobe and
(1) For both exposed and concealed work in normally dry covered with plaster, adobe, or similar finish
locations except as prohibited in 334.10(3) (4) Where exposed or subject to excessive moisture or
(2) To be installed or fished in air voids in masonry block dampness
or tile walls
(B) Type NMC. Type NMC cable shall be permitted as 334.15 Exposed Work. In exposed work, except as pro -
follows: vided in 300.11(A), cable shall be installed as specified in
(1) For both exposed and concealed work in dry, moist,
334.15(A) through (C).
damp, or corrosive locations, except as prohibited by (A) To Follow Surface. Cable shall closely follow the sur-
334.10(3) face of the building finish or of running boards.
(2) In outside and inside walls of masonry block or tile
(3) In a shallow chase in masonry, concrete, or adobe pro- (B) Protection from Physical Damage. Cable shall be
tected against nails or screws by a steel plate at least protected from physical damage where necessary by rigid
1.59 mm (' /ib in.) thick and covered with plaster, adobe, metal conduit, intermediate metal conduit, electrical metal-
or similar finish lic tubing, Schedule 80 PVC rigid nonmetallic conduit, or
other approved means. Where passing through a floor, the
(C) Type NMS. Type NMS cable shall be permitted as cable shall be enclosed in rigid metal conduit, intermediate
follows: metal conduit, electrical metallic tubing. Schedule 80 PVC
(1) For both exposed and concealed work in normally dry rigid nonmetallic conduit, or other approved means extend -
locations except as prohibited by 334.10(3) ing at least 150 mm (6 in.) above the floor.
(2) To be installed or fished in air voids in masonry block Where Type NMC cable is installed in shallow chases
or tile walls in masonry, concrete, or adobe, the cable shall be protected
against nails or screws by a steel plate at least 1.59 mm
334.12 Uses Not Permitted. (1/46 in.) thick and covered with plaster, adobe, or similar
finish.
(A) Types NM, NMC, and NMS. Types NM, NMC, and
NMS cables shall not be permitted as follows: (C) In Unfinished Basements. Where cable is run at
(1) In any dwelling or structure not specifically permitted angles with joists in unfinished basements, it shall be per-
in 334.10(1), (2), and (3) missible to secure cables not smaller than two 6 AWG or
2005 Edition NATIONAL ELECTRICAL CODE 70-179