Vi har precis köpt ett hus i Chicago-området och funnit att det inte finns någon jordledare i några av de nyligen anslutna områdena. Jag trodde att den nationella elkoden kräver en jordledning för nybyggnation och ombyggnad, i motsats till att lita på stålröret som mark. Är detta korrekt?
Rörledning (RMC, IMC eller EMT) är en NEC-accepterad markbana. Så, om ledningarna är i stålrör, krävs ingen annan jordledning.
Om det ger dig bekymmer kan du hitta den här länken som rapporterar forskning om rörlens effektivitet som en grund avlastar dem.
National Electrical Code gör det möjligt att använda metallledningar och slangar som en jordad jordledare, så länge den är ordentligt installerad.
Men innan du använder den som sådan i en befintlig installation, bör du verifiera att den ger en tillräcklig kontinuerlig väg till marken.
National Electrical Code 2014
Chapter 3 Wiring Methods
Article 342 Intermediate Metal Conduit: Type IMC
342.60 Grounding. IMC shall be permitted as an equipment grounding conductor.
Article 344 Rigid Metal Conduit: Type RMC
344.60 Grounding. RMC shall be permitted as an equipment grounding conductor.
Article 348 Flexible Metal Conduit: Type FMC
348.60 Grounding and Bonding. If used to connect equipment where flexibility is necessary to minimize the transmission of vibration from equipment or to provide flexibility for equipment that requires movement after installation, an equipment grounding conductor shall be installed.
Where flexibility is not required after installation, FMC shall be permitted to be used as an equipment grounding conductor when installed in accordance with 250.118(5).
Where required or installed, equipment grounding conductors shall be installed in accordance with 250.134(B).
Where required or installed, equipment bonding jumpers shall be installed in accordance with 250.102.
Article 350 Liquidtight Flexible Metal Conduit: Type LFMC
350.60 Grounding. Grounding and bonding for LFMC shall be installed in accordance with 350.60(A) and (B).
(A) If used to connect equipment where flexibility is necessary to minimize the transmission of vibration from equipment or to provide flexibility for equipment that requires movement after installation, an equipment grounding conductor shall be installed.
Where flexibility is not required after installation, LFMC shall be permitted to be used as an equipment grounding conductor when installed in accordance with 250.118(6).
Where required or installed, equipment grounding conductors shall be installed in accordance with 250.134(B).
Where required or installed, equipment bonding jumpers shall be installed in accordance with 250.102.
(B) Where Air Conditioning or Refrigerating Equipment is installed outdoors, an equipment grounding conductor per 250.118(1) shall be provided within the raceway and shall be sized per 250.122.
Article 358 Electrical Metallic Tubing: Type EMT
358.60 Grounding. Grounding and bonding EMT shall be installed in accordance with 358.60(A) and (B).
(A) EMT shall be permitted as an equipment grounding conductor
(B) Where Air Conditioning or Refrigerating Equipment is installed outdoors, an equipment grounding conductor per 250.118(1) shall be provided within the raceway and shall be sized per 250.122.
Article 360 Flexible Metallic Tubing: Type FMT
360.60 Grounding. FMT shall be permitted as an equipment grounding conductor where installed in accordance with 250.118(7).
Läs andra frågor om taggar code-compliance grounding grounding-and-bonding Kärlek och kompatibilitet Skor Gear 12 Stjärntecken Grunderna