Flame Retardant

AFAIK all Art 310 conductors for general wiring have a certain degree of flame and smoke producing resistance.

The RHW-RHH conductors should be rubber based material where the XHHW is cross linked polyethylene based material.
 
Alwayslearningelec said:
I dont this exists in XHHW, correct? RHH-RHW I beleive it does.
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I would write an RFI to clarify is you can just use THHN/THWN which is listed in Table 310.104(A) as
Flame-retardant moisture- and heat-resistant Thermoplastic instead of thermoset XHHW.
 
infinity said:
I would write an RFI to clarify is you can just use THHN/THWN which is listed in Table 310.104(A) as
Flame-retardant moisture- and heat-resistant Thermoplastic instead of thermoset XHHW.
Click to expand...
I will and also look into 310.14 but I assume XHHW is not flame retardant and THHN/THWN is?? If so that's odd. I'd think if THHN is then XHHW surely would be.
 
Ac
infinity said:
I would write an RFI to clarify is you can just use THHN/THWN which is listed in Table 310.104(A) as
Flame-retardant moisture- and heat-resistant Thermoplastic instead of thermoset XHHW.
Click to expand...
I see table 310.4. xhhw-2 is flame retardant and moisture resistant so I think xhhw-2 will comply with spec I listed.
 
For large condcutors I don't recall seeing much of a difference between copper XHHW and THHN when it comes to installation. I remember back in the day when we used XHHW in small sizes like #12 and #10 at the World Trade Center (their spec) and it was horrible to work with. It was terrible to pull in a raceway because the insulation was not slick in any way. You couldn't skin it with wire strippers. You had to literally crush the insulation with your pliers and break the insulation off. I'm assuming that the new stuff now like Southwire's SIMpull is better.
 
I always specify XHHW for any wet location installation and for conductors in ferrous raceways between a VFD and the driven motor.
In sizes 6 AWG and smaller the diameter of XHHW is greater than that of THHN/THWN.
 
According to UL 44 Standard Type XHHW-2, RHW-2, XHHW, XHH, RHW, RHH, and SA cable is tested as per VERTICAL-TRAY FLAME TEST [UL Flame Exposure test, Sections 4 – 11 of Vertical-Tray Fire-Propagation and Smoke-Release Test for Electrical and Optical-Fiber Cables, UL 1685 or the FT4/IEEE 1202 Type of Flame Exposure test, Sections 12 – 19 of UL 1685]
However, single core cable of 4-1 awg has to be green colored and marked D or M.
Vertical tray flame test is done according to VW-1 [UL 1581]
 
Sorry. The flame-retardant cable has to be marked as per UL 44 60.20

60.20 Multiple-conductor and single-conductor wires and cables of Type XHHW-2, RHW-2, XHHW, XHH,RHW, RHH, and SA that comply with the flame-propagation and smoke-release requirements indicated in
57.1 and 57.2 are eligible to be marked on the outer surface with the designation ²-LS². Where used, the ²-LS² designation shall be added as a suffix immediately following the type letters.
 
Sorry again. It has to be:
are eligible to be marked on the outer surface with the designation "-LS".
 
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