225.10 Wiring on Buildings (or Other Structures).
Code Change Summary: Revisions to the type of wiring methods permitted for outdoor wiring.
NEC Section 225.10 specifies all the wiring methods permitted to be used outdoors for branch circuits or feeders. In the 2020 NEC®, item 11 (multiconductor cable) was deleted so as not to give the impression that certain dry location cables such as type NM (nonmetallic sheathed cable) could be used for outdoor branch circuits or feeders in damp or wet locations.
Items 17 and 18 were added to the list since both SE cable (service entrance) and TC-ER (tray cable suitable for exposed run between a cable tray and the utilization equipment) are permitted for outdoor branch circuits and feeders as long as the rules in those cable articles are followed and the cable types are suitable for the location.
Below is a preview of the NEC®. See the actual NEC® text at NFPA.ORG for the complete code section. Once there, click on their link to free access to the 2020 NEC® edition of NFPA 70.
2017 Code Language:
225.10 Wiring on Buildings (or Other Structures). The installation of outside wiring on surfaces of buildings (or other structures) shall be permitted for circuits not exceeding 1000 volts, nominal, as the following:
(1) Auxiliary gutters
(2) Busways
(3) Cable trays
(4) Cablebus
(5) Electrical metallic tubing (EMT)
(6) Flexible metal conduit (FMC)
(7) Intermediate metal conduit (IMC)
(8) Liquidtight flexible metal conduit (LFMC)
(9) Liquidtight flexible nonmetallic conduit (LFNC)
(10) Messenger-supported wiring
(11) Multiconductor cable
(12) Open wiring on insulators
(13) Reinforced thermosetting resin conduit (RTRC)
(14) Rigid metal conduit (RMC)
(15) Rigid polyvinyl chloride conduit (PVC)
(16) Type MC cable
(17) Type MI cable
(18) Type UF cable
(19) Wireways
Circuits of over 1000 volts, nominal, shall be installed as provided in 300.37.
2020 Code Language:
225.10 Wiring on Buildings (or Other Structures). The installation of outside wiring on surfaces of buildings (or other structures) shall be permitted for circuits not exceeding 1000 volts, nominal, as the following:
(1) Auxiliary gutters
(2) Busways
(3) Cable trays
(4) Cablebus
(5) Electrical metallic tubing (EMT)
(6) Flexible metal conduit (FMC)
(7) Intermediate metal conduit (IMC)
(8) Liquidtight flexible metal conduit (LFMC)
(9) Liquidtight flexible nonmetallic conduit (LFNC)
(10) Messenger-supported wiring
(11) Open wiring on insulators
(12) Reinforced thermosetting resin conduit (RTRC)
(13) Rigid metal conduit (RMC)
(14) Rigid polyvinyl chloride conduit (PVC)
(15) Type MC cable
(16) Type MI cable
(17) Type SE cable
(18) Type TC-ER cable
(19) Type UF cable
(20) Wireways
Circuits of over 1000 volts, nominal, shall be installed as provided in 300.37.