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Is Tray Cable acceptable for Residential use?

19K views 43 replies 7 participants last post by  Stubbie 
#1 ·
#3 ·
#8 ·
How about using SE-R from the main panel through the crawl space and then splicing into USE-2 in an LB on the outside of the house and from there take the USE-2 to the panel in the garage? If this works, can the USE-2 be inside conduit within the walls? It would need to be piped about 7' in the same exterior wall it came in, up to the panel. I can run the conduit up the outside of the wall and into the panel, but I would rather use the pvc that was put in the foundation specifically for this. Both cables would #2 AL with a #4 ground.
 
#12 ·
OK, after some reading it seems I need to figure out the box fill calculation for anything larger 6 awg being spliced in a junction box. The calculation being based on the trade(?) size of the conduit being used and whether it is a straight or angle pull. Straight times 8 and angle times 6. If it is an angle pull/splice using 2" pvc conduit, I would multiply 2 x 6 and get a 12" x 12" junction box? Am I even in the parking lot of the ball park with this???
 
#17 ·
I need to get from my main panel in my house to the imaginary sub-panel in my garage. Total run of about 125'. 60' in my crawl space, 50' buried and the remaining 15' in the walls up to the panels, both on exterior walls. The plan was to use SER from the main to the end of the crawl space and splice into USE2 outside and take that up into the garage panel. Both being 2-2-2-4 AL.
 
#21 ·
The thing you are going to run into is that splicing the wire with proper connectors taping heat shrink tubing and a large enough junction box is after all that you have spend more money than if you would have used USE 2 in conduit the whole length.
 
#30 ·
Use USE 2 in conduit and direct bury the wire outside 24" MIN below grade. Having the wire in conduit for peace of mind would only add 30 bucks at most to your project. Be sure to order 20% extra just in case because this stuff does not stretch.
 
#33 ·
#39 · (Edited)
Copied from nec

II. Installation
336.10 Uses Permitted. Type TC cable shall be permitted
to be used as follows:
(1) For power, lighting, control, and signal circuits.
(2) In cable trays.
(3) In raceways.
(4) In outdoor locations supported by a messenger wire.
(5) For Class 1 circuits as permitted in Parts II and III of
Article 725.
(6) For non–power-limited fire alarm circuits if conductors
comply with the requirements of 760.49.
(7) In industrial establishments where the conditions of
maintenance and supervision ensure that only qualified
persons service the installation, and where the cable is
continuously supported and protected against physical
damage using mechanical protection, such as struts,
angles, or channels, Type TC tray cable that complies
with the crush and impact requirements of Type MC
cable and is identified for such use with the marking
Type TC–ER shall be permitted between a cable tray
and the utilization equipment or device. The cable shall
be secured at intervals not exceeding 1.8 m (6 ft).
Equipment grounding for the utilization equipment
shall be provided by an equipment grounding conductor
within the cable. In cables containing conductors
sized 6 AWG or smaller, the equipment grounding conductor
shall be provided within the cable or, at the time
of installation, one or more insulated conductors shall
be permanently identified as an equipment grounding
conductor in accordance with 250.119(B).
Exception: Where not subject to physical damage, Type
TC-ER shall be permitted to transition between cable trays
and between cable trays and utilization equipment or devices
for a distance not to exceed 1.8 m (6 ft) without
continuous support. The cable shall be mechanically supported
where exiting the cable tray to ensure that the minimum
bending radius is not exceeded.
(8) Where installed in wet locations, Type TC cable shall
also be resistant to moisture and corrosive agents.
Informational Note: See 310.15(A)(3) for temperature
limitation of conductors.
336.12 Uses Not Permitted. Type TC tray cable shall not
be installed or used as follows:
(1) Installed where it will be exposed to physical damage
(2) Installed outside a raceway or cable tray system, except
as permitted in 336.10(4) and 336.10(7)
(3) Used where exposed to direct rays of the sun, unless
identified as sunlight resistant
(4) Direct buried, unless identified for such use
336.24 Bending Radius. Bends in Type TC cable shall be
made so as not to damage the cable. For Type TC cable
without metal shielding, the minimum bending radius shall
be as follows:
(1) Four times the overall diameter for cables 25 mm
(1 in.) or less in diameter
(2) Five times the overall diameter for cables larger than
25 mm (1 in.) but not more than 50 mm (2 in.) in
diameter
(3) Six times the overall diameter for cables larger than
50 mm (2 in.) in diameter
Type TC cables with metallic shielding shall have a
minimum bending radius of not less than 12 times the cable
overall diameter.
336.80 Ampacity. The ampacity of Type TC tray cable
shall be determined in accordance with 392.80(A) for 14
AWG and larger conductors, in accordance with 402.5 for
18 AWG through 16 AWG conductors where installed in
cable tray, and in accordance with 310.15 where installed in
a raceway or as messenger-supported wiring.
III.
 
#42 ·
Cable trays are discussed in NEC 392 and are long metal or pvc trays that the TC cable lays in. When used in cable trays special tables are used for ampacity.

Otherwise you would simply use 310.16 for the type of insulation .. provided the insulation is of a type listed in those tables. There are many styles and insulations of power tray cable so you need to make sure it is 'power cable' and a insulation type that is acceptable for residential use such as those in table 310.16

The designation type tc simply means it can be used in trays where other cables cannot go. Theres nothing special about it after that.

Loadcenters are nothing more than distribution panelboards .. they are just specialized for residential applications.

They are not trays ... they are devices used to distribute power.
 
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