Service Loops in NM Wire

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tom baker

tom baker

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On a Facebook reel, there was a video showing a NM wiring to device boxes with a service loop above the box of perhaps 2 feet. The wire was stapled before it entered the device box. How common is it to leave a device loop in the wiring? The explanation was to allow later moves of the box.
 
tom baker said:
On a Facebook reel, there was a video showing a NM wiring to device boxes with a service loop above the box of perhaps 2 feet. The wire was stapled before it entered the device box. How common is it to leave a device loop in the wiring? The explanation was to allow later moves of the box.
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Once you close it in, moving the boxes is not that easy. Probably doesn't hurt anything to leave a service loop but I don't think I would leave it for every device. Only the ones I thought might move.
 
tom baker said:
On a Facebook reel, there was a video showing a NM wiring to device boxes with a service loop above the box of perhaps 2 feet. The wire was stapled before it entered the device box. How common is it to leave a device loop in the wiring? The explanation was to allow later moves of the box.
Click to expand...
I have always left about a 8” service loop on NM cable…..has come in handy on several occasions after the drywall hacks damaged the wiring in the box!
 
tom baker said:
On a Facebook reel, there was a video showing a NM wiring to device boxes with a service loop above the box of perhaps 2 feet. The wire was stapled before it entered the device box. How common is it to leave a device loop in the wiring? The explanation was to allow later moves of the box.
Click to expand...
I do a smaller on by stapling or stacking with in 4 inches of the box and leaving just enough that I can pull out a bit and wago onto it.
 
infinity said:
I thought that it was for when the sheetrockers cut the wires in the box you can pull in some extra cable and start over after the wall is closed.
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Now that I'm retired and being nosey I have walked around job sites at times and have asked several residential EC's about this and they say this is the reason.
 
roger said:
Now that I'm retired and being nosey at times I walk around job sites at times and have asked several residential EC's about this and they say this is the reason.
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Someone recently sent me that photo and they told me it was for the crazy Rotozip guys.
 
roger said:
Now that I'm retired and being nosey I have walked around job sites at times and have asked several residential EC's about this and they say this is the reason.
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So I never used to but then I had multiple instances of this. I feel like it was intentional to be this bad.
 

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The 2020 code added language to address this.
334.30 Securing and Supporting.
Nonmetallic-sheathed cable shall be supported and secured by staples, cable ties listed and identified for securement and support, or straps, hangers, or similar fittings designed and installed so as not to damage the cable, at intervals not exceeding 1.4 m (41⁄2 ft) and within 300 mm (12 in.) of every cable entry into enclosures such as outlet boxes, junction boxes, cabinets, or fittings. The cable length between the cable entry and the closest cable support shall not exceed 450 mm (18 in.). Flat cables shall not be stapled on edge.

Sections of cable protected from physical damage by raceway shall not be required to be secured within the raceway.
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Tulsa Electrician said:
Any idea why the nail plates on back of box.
The loops appear to be longer than 18" between entry and cable support.
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Some anal inspectors want them for the adjacent wall because of how close the cable is entering the box. Makes no sense because you can't really drive them in from just one end being on the stud.
 
I don't understand the large service loops either. If you make your boxes up and tuck the wires neatly, the rotozip guys can't reach them with their wire destruction bits. And how many times has someone been called back to move a box? I like to plan ahead....but that is crazy to me.
 
don_resqcapt19 said:
Prior to the 2020 code, this was not addressed and in many cases the AHJ would not permit more than 12" of cable between the enclosure and the first staple.
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I still keep it to 12 inches that's more than enough to pull down rotozip damage and not need to extend the wires in the box. 18 inches at the panel is nice though since sometimes you need to fan out the conductors to save the top large KOs for future use.
 
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