Quad Plex

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S

SAP

Senior Member
Location
Fresno Ca
What size quad Plex aluminum do I need for 100 Amp over head feeder for subpanel, and we're do I find it in the NEC thanks
 
S

SAP

Senior Member
Location
Fresno Ca
I know residential services and feeders have their own table 310.15(B)(7) this is the situation existing #6 THHN ,THWN copper over head feeder feeding a 100 Amp sub 20 feet apart, I'm doing a service change on this job, I need to know if I had to upsize this existing feeder thanks
 
Smart $

Smart $

Esteemed Member
Location
Ohio
iwire said:
Just keep in mind termination temperatures and voltage drop.
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At the very least terminal temp. 110.14(C) only permits us to use 310.15(B)(16) to determine minimum size. So to otherwise comply, a higher temperature transition remote to the terminal enclosure would be necessary.
 
kwired

kwired

Electron manager
Location
NE Nebraska
"Table 310.15(B)(20): (formerly Table 310.20) Ampacities of Not More Than Three Single Insulated Conductors, Rated Up to and Including 2000 Volts, Supported on a Messenger, Based on Ambient Air Temperature of 40°C (104°F)"
 
Smart $

Smart $

Esteemed Member
Location
Ohio
kwired said:
"Table 310.15(B)(20): (formerly Table 310.20) Ampacities of Not More Than Three Single Insulated Conductors, Rated Up to and Including 2000 Volts, Supported on a Messenger, Based on Ambient Air Temperature of 40°C (104°F)"
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110.14(C)...
(1) Equipment Provisions. The determination of termination
provisions of equipment shall be based on 110.14(C)(1)(a) or
(C)(1)(b). Unless the equipment is listed and marked otherwise,
conductor ampacities used in determining equipment termination
provisions shall be based on Table 310.15(B)(16) as
appropriately modified by 310.15(B)(7).
Click to expand...
 
Besoeker

Besoeker

Senior Member
Location
UK
Smart $ said:
Four single insulated aluminum conductors (perhaps one bare, depending on who's selling, who's asking) twisted into a cable without a sheath.
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Thank you kindly. It isn't something I have ever seen.
The only application I've come across using aluminium conductors are the bus bars on high current rectifiers.
 
Besoeker

Besoeker

Senior Member
Location
UK
Smart $ said:
Just do a Google image search for "quadruplex cable"...
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Perhaps I should have said not ever seen used.
Mostly we use stranded copper conductors for installations, typically not less than 2.5mm^2 and 1.0mm^2 flexible for the internal control wiring in panels.
 
iwire

iwire

Moderator
Staff member
Location
Massachusetts
Besoeker said:
Perhaps I should have said not ever seen used.
Mostly we use stranded copper conductors for installations, typically not less than 2.5mm^2 and 1.0mm^2 flexible for the internal control wiring in panels.
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The 'plex' cables, twin, tri, quad etc are only used for outdoor wiring on poles. or direct buried.

It is almost the only thing the power companies use here for circuits under 600 volts.

The bare conductor is made with an alloy to add strength for supporting the insulated conductors.

Residence_service_drop.JPG
 
iwire

iwire

Moderator
Staff member
Location
Massachusetts
kwired said:
One would need termination method rated for the application I guess, otherwise what good is it to have all those other tables if we are stuck with termination temps from just one of them?
Click to expand...

One way to take advantage of those tables is to terminate those conductors to larger conductors with connectors listed for those temperatures.
 
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