Solid vs. Stranded....

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cschmid

Senior Member
Larry is correct the heat from higher amp items causes the spring tension to weaken and then the heating is increased and the process becomes accelerated..

crimp on terminals come in many forms and the bare (non insulated) ones I use fit nicely in a box..yes they are more labor intensive yet used with a higher grade receptacle they can take the punishment of a college campus..

solid wire breaks when it is crimped, it can not be pulled out of the pipe without removing more then one, it is more labor intensive due to its rigidness, the only benefit is its termination ability, it loosens on the screws when folded up in outlet box, it does not move easily enough to identify it in a group in a box you must pull whole group of wires out of box to work with them, the list goes on..

now lets enter the twelve step program and just say no to solid wire..even if you can save 20 dollars on wire for the job..so save labor as it is easy to burn that up in labor..
 

macmikeman

Senior Member
Its a common spec thats been around for decades. I see it all the time. No electrical specifier I ever asked could answer me why it is consistantly showing up in their specs. Same goes for powdered soapstone as the only allowed pulling lubricant. These guys know we are going to use wirelube, but they still keep adding the soapstone sentence into the spec. Must be traditional.
 
sparky 134 said:
I've never had a problem terminating stranded onto a device. Just leave an inch or so of insulation on the end of the wire to control any fraying.

Solid is a PITA to pull, IMO.

While this may pass inspection where you are, if this is noticed here, the inspecters start acting like "Sherlock Holmes" and will find any actionable violation to needle you with. I have talked with a few and one of their points is fire from the termination loosening and heating up as the strands settle or fraying and faulting. Seems like a valid point since they had stood in the burned out buildings as experts with the fire martial and later in court to testify to the same.

I don't want to know what is fastest or easiest. If it is found ultimately more dangerous then I will eat the expense and sleep better.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
I've heard tricks from leaving a piece of insulation on the wire to left-hand twisting of the strands.

I simply pinch the wire loop closed with the tip of needle-nose pliers while tightening the screw.
 

jflynn

Senior Member
ultramegabob said:
the only time I use solid in commercial is M.C. cable, stranded is worth the extra money when pulling through conduit,

Same here,we only use solid when spec;d,usually for fire alarm. Stranded is definetly easier to pull than solid
 

ramsy

Roger Ruhle dba NoFixNoPay
Location
LA basin, CA
Occupation
Service Electrician 2020 NEC
rook81108 said:
here, the inspecters start acting like "Sherlock Holmes" ..one of their points is fire from the termination loosening and heating up as the strands settle or fraying and faulting.

Learned about exploding strands as a rookie configuring fire-alarm relays for airport-luggage beltways. After changing some dip switches and trying to close the outlet box there was a flash bang at arms length, followed by terrified retardation for about 15 minutes.

Not being shown the disconnect was bad, discovering it was 480vac after the fact was worse, but finding the charred remains of a loose strand was a relief, since everything worked fine after that, minus one strand.
 

cschmid

Senior Member
had a fellow worker install a new relay once and had some problems what i found when i was done ttrouble shooting it was one strand was bent back and touching another wire..this made the plc program not function properly was a real pain..I use a special crimp for under terminals..

when I find the terminal I will post pic..
 
cschmid said:
had a fellow worker install a new relay once and had some problems what i found when i was done ttrouble shooting it was one strand was bent back and touching another wire..this made the plc program not function properly was a real pain..I use a special crimp for under terminals..

when I find the terminal I will post pic..
Like a ferrule?
 

JBF3

Member
larryfine, is this the reason that stranded is used over solid for low voltage lighting ? because of the cycling of current loosening the connections or burning them out
 

peter d

Senior Member
Location
New England
JBF3 said:
larryfine, is this the reason that stranded is used over solid for low voltage lighting ? because of the cycling of current loosening the connections or burning them out

I'd say the main reason is that low-voltage lighting generally requires pretty large conductors due to voltage drop (#12 and up.) Working with solid conductors and low-voltage stuff would be an absolute nightmare.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
JBF3 said:
larryfine, is this the reason that stranded is used over solid for low voltage lighting ? because of the cycling of current loosening the connections or burning them out
I imagine stranded is used for LV because the low voltage requires high current, which requires a larger conductor, which requires stranded for flexibility.

I'm not aware of LV being harder on connections than line voltage. Amps is amps. It may be that LV is harder on the installer, because more care is needed.
 

jrannis

Senior Member
jflynn said:
ultramegabob said:
the only time I use solid in commercial is M.C. cable, stranded is worth the extra money when pulling through conduit,

Same here,we only use solid when spec;d,usually for fire alarm. Stranded is definetly easier to pull than solid

They do make stranded MC cable. I ordered several thousand feet for a project a couple of years ago. It worked out really nice.
 
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