Running control wiring in power conduit for EV Charger amperage control. 725.26(B)(1).

[jaggedben]

...
-
So what would it take to get 18 gauge communication wire in the same existing conduit as 40A 240V power delivery?

You could try making your own twisted pair with class 1 conductors. (See discussion in that thread.) Hopefully interference isn't a problem.

I agree with Larry and others that the meter which takes the CT secondaries as input and outputs the RS-485 should not be in the panel. The proper location would be a j-box adjacent to the panel. The RS-485 could leave by a different direction and rejoin the 40A EV circuits in a T-condulet.

I just told you. A cable rated at 600V! You said you had a source for it didn't you?

I believe it either has to be listed by the manufacturer or Class 1 conductors. For example there is Cat6 with an outer 600V jacket, but that's not code compliant unless listed. I believe it will work fine, and I've used it with high voltage DC with manufacturers blessing (although in retrospect, I'm a bit skeptical they got it listed).

 

[brycenesbitt]

Wow! Looking at that mess in a panel I can't see how that would be allowed. And it probably isn't. CT leads need to go outside. Why do you think they are so long?
-Hal

The Emporia Vue is UL and CE listed for direct install in a panel. Not only that, but it's listed and used for EV charge throttling, just like the Wallbox.

The alternative is a mess of CT wires going out the panel which, even if possible, creates its own hazard. Agreed 100% it's a tangled mess.

 

[hbiss]

You could try making your own twisted pair with class 1 conductors. (See discussion in that thread.) Hopefully interference isn't a problem.

Absolutely not! He can use a 600V rated CABLE. NOT INDIVIDUAL CONDUCTORS regardless of what the insulation is!

-Hal

 

[don_resqcapt19]

The Emporia Vue is UL and CE listed for direct install in a panel. Not only that, but it's listed and used for EV charge throttling, just like the Wallbox.

The alternative is a mess of CT wires going out the panel which, even if possible, creates its own hazard. Agreed 100% it's a tangled mess.

The CE mark is a statement of self evaluation of the product to the standards by the manufacture. It is not a third party listing and the CE mark is not an acceptable indication that the product meets the requirements for a US installation.

 

[jaggedben]

Absolutely not! He can use a 600V rated CABLE. NOT INDIVIDUAL CONDUCTORS regardless of what the insulation is!

-Hal

Code section?

(Also I don't see why it needs to be 600V if the mains power is 240V. But that's a minor point.)

 

[jaggedben]

The Emporia Vue is UL and CE listed for direct install in a panel. Not only that, but it's listed and used for EV charge throttling, just like the Wallbox.

I don't think that establishes that it's okay to have your Class 2 circuit running through the panel when it's not necessary.

The alternative is a mess of CT wires going out the panel which, even if possible, creates its own hazard. Agreed 100% it's a tangled mess.

Nonsense. Having the CT leads bundled in the panel is a bigger mess, and the hazard is reduced, not increased, by not having the RS-485 terminations in the panel. While there is room for disagreement as to whether you're allowed to have the Emporia in the panel, you're way off the mark here. Just say it doesn't make a difference.

 

[jaggedben]

Code section?

(Also I don't see why it needs to be 600V if the mains power is 240V. But that's a minor point.)

I take back the part about 600V here.

 

[hbiss]

Code section?

(Also I don't see why it needs to be 600V if the mains power is 240V. But that's a minor point.)

Understand the difference between a listed 600V CABLE and individual CONDUCTORS with 600V insulation.

A cable may be run on its own, restricted only by its construction and environment. There is no restriction on running it with other cables or conductors up to its voltage rating. Think MC, NM, etc.

Conductors can only be run in a Chapter 3 conduit or raceway or as part of a cable assembly. Think THWN, etc.

725.136 Separation from Electric Light, Power, Class 1, Non–
Power-Limited Fire Alarm Circuit Conductors, and Medium-
Power Network-Powered Broadband Communications Cables.

(I) Other Applications

. For other applications, conductors of
Class 2 and Class 3 circuits shall be separated by at least 50 mm
(2 in.) from conductors of any electric light, power, Class 1
non–power-limited fire alarm or medium power networkpowered
broadband communications circuits unless one of the
following conditions is met:

(1) Either (a) all of the electric light, power, Class 1, non–
power-limited fire alarm and medium-power networkpowered
broadband communications circuit conductors
or (b) all of the Class 2 and Class 3 circuit conductors are
in a raceway or in metal-sheathed, metal-clad, non–
metallic-sheathed, or Type UF cables.

All of the Class 2 and Class 3 circuit conductors are... in a non-metallic sheathed... cable.

-Hal

 

[brycenesbitt]

That said, I know they make CAT-5e and CAT-6 cable with a 600V rating for industrial control panel wiring. So if you can find a (single pair shielded?) RS-485 cable with a 600V rating you could run that with your power conductors.
-Hal

Would this be suitable?

https://www.wireandcableyourway.com...tation-cable-w-overall-shield-type-tc-er-600v
18/1PR Type TC, Tray Cable, Overall Shield, 600V
Permitted use in Class 1, Division 2 industrial hazardous locations per NEC. Listed Type TC.
Rated at 90°C dry, 75°C wet

Any corrections to this code citation? Under 2020 NEC 725.48:

Where the RS-485 wire is "Class 1" and the 40A 240V volt power to the EVSE is a "Power Supply" circuit.
-
Then under 725.49:

With ampacity adjustments from table 310.15(C)(1) where the power supply conductors is more than three.
Whew. Anything else?
--
The 18 gauge conductors are not necessarily rated (I don't know actually), but the cable assembly is rated at 600V Class 1.

 

[brycenesbitt]

725.49(B) reads "insulation on conductors" rather than "insulation on cable". What should I be reading into that?

 

[jaggedben]

Understand the difference between a listed 600V CABLE and individual CONDUCTORS with 600V insulation.

...

Code Section????

See 725.130(A) Exception 2, for 2020 NEC or earlier. Already cited above.

In the 2023 see 725.136(H). The requirement for the the circuit to be functionally related seems to gave been dropped in the reorganization, unless I just haven't yet found where they put it.

The only reason for the the 'make you're own twisted pair' suggestion was RS-485 functionality. Code would allow them to be pulled straight.

 

[wwhitney]

In the 2023 see 725.136(H). The requirement for the the circuit to be functionally related seems to gave been dropped in the reorganization, unless I just haven't yet found where they put it.

724.48(B)(1)

Cheers, Wayne

 

[jaggedben]

Would this be suitable?

https://www.wireandcableyourway.com...tation-cable-w-overall-shield-type-tc-er-600v
18/1PR Type TC, Tray Cable, Overall Shield, 600V
Permitted use in Class 1, Division 2 industrial hazardous locations per NEC. Listed Type TC.
Rated at 90°C dry, 75°C wet

Any corrections to this code citation? Under 2020 NEC 725.48:
View attachment 2568151
Where the RS-485 wire is "Class 1" and the 40A 240V volt power to the EVSE is a "Power Supply" circuit.
-
Then under 725.49:
View attachment 2568152
With ampacity adjustments from table 310.15(C)(1) where the power supply conductors is more than three.
Whew. Anything else?
--
The 18 gauge conductors are not necessarily rated (I don't know actually), but the cable assembly is rated at 600V Class 1.

The TC cable type only helps you out in cable tray, not any other kind of raceway.

725.49(B) reads "insulation on conductors" rather than "insulation on cable". What should I be reading into that?

If the conductors inside the cable are marked as one of the types in that section, then I guess it's okay? The cable then becomes irrelevant? That's my take.

I have seen type TC cable approved for this sort of use under a manufacturers listing, but otherwise I don't see where it's approved by the code.

 

[wwhitney]

The TC cable type only helps you out in cable tray, not any other kind of raceway.

Not following, doesn't the listing as Type TC cable make it a Chapter 3 wiring method, so it is suitable for a Class 1 circuit?

Also (2020) 336.10(3) lists "in raceways" as a permitted use for Type TC cable.

Cheers, Wayne

 

[jaggedben]

724.48(B)(1)

Cheers, Wayne

Yes, and thanks. But unclear if 725.136(H) incorporates that? (Errata? I wonder if the latter was supposed to say 724.48 instead of 724.46. Or both, or more.)

 

[hbiss]

Would this be suitable?

https://www.wireandcableyourway.com...tation-cable-w-overall-shield-type-tc-er-600v
18/1PR Type TC, Tray Cable, Overall Shield, 600V
Permitted use in Class 1, Division 2 industrial hazardous locations per NEC. Listed Type TC.
Rated at 90°C dry, 75°C wet

That would be fine.

The TC cable type only helps you out in cable tray, not any other kind of raceway.

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, including those with mechanically discontinuous
segments up to 300 mm (1 ft).
(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.

-Hal

 

[jaggedben]

Not following, doesn't the listing as Type TC cable make it a Chapter 3 wiring method, so it is suitable for a Class 1 circuit?

Also (2020) 336.10(3) lists "in raceways" as a permitted use for Type TC cable.

Cheers, Wayne

Okay, the way I read 725.49, if 14awg or larger then yes, but if 16awg or smaller then then it must be one of the types listed in (B), and TC isn't there. Unless the TC cable is listed for Class 1, which maybe they all mostly are, I actually don't know. Unclear to me if the product he's posting is actually listed. (They say 'permitted.' By what, or whom?)

I mean, I think it's fine, but since we're arguing the minutiae...

 

[wwhitney]

Okay, the way I read 725.49, if 14awg or larger then yes, but if 16awg or smaller then then it must be one of the types listed in (B), and TC isn't there.

It wouldn't, as TC isn't an insulation type for individual conductors, it's a cable type. But I see your point, the product description for the item referenced doesn't indicate that the inner conductors are one of the insulation types specified in 725.49(B). So that requires confirmation.

Cheers, Wayne

 

[brycenesbitt]

Another source

https://www.mouser.com/c/wire-cable/multi-conductor-cables/?number%20of%20conductors=2%20Pair%20Twisted&voltage%20rating=600%20V

It wouldn't, as TC isn't an insulation type for individual conductors, it's a cable type. But I see your point, the product description for the item referenced doesn't indicate that the inner conductors are one of the insulation types specified in 725.49(B). So that requires confirmation.
Cheers, Wayne

The source below claims that a TC rating is synonymous with a 600V rating for NEC purposes:

The National Electrical Code does not recognize Appliance Wiring Materials (AWM) wiring. Category cables that meet a 600 V AWM rating would still need to be separated from power cables. The NEC does recognize and provide provisions for CM, CMR, CMP and PLTC cables. Standard category cables can be dual listed to a CM, CMR, CMP or PLTC listing, but these constructions are rated to 300 V and would not be permitted to be installed near 600 V cables.

Instead, NEC allows the use of 600 V multiconductor cable under the listing Type TC (tray cable)....Type TC category cables are permitted to be installed in cable trays and raceways next to other 600 V cables without separation depending on the application.

Category cables that meet a 600 V AWM rating would not need to be separated from power cables for NFPA 79 applications. NFPA 79 Section 12.9.2 provides additional information.

See https://www.anixter.com/en_us/resources/literature/wire-wisdom/600-v-category-cable.html
--
And understand why it's confusing? Is 725.49(B) artfully drafted? Why would the inner wires matter at all for NEC purposes, if a heavy exterior jacket protects them? I can't find any vendor that specifies a voltage rating for the inner cores. Example https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/2454/CF5 Series Datasheet.pdf
__

 

[wwhitney]

But I see your point, the product description for the item referenced doesn't indicate that the inner conductors are one of the insulation types specified in 725.49(B). So that requires confirmation.

FWIW, UL Standard 1277 for Tray Cable specifies in section 9.2.1(b) that any #18 or #16 conductors be insulated as one of the types of UL 66 for Fixture Wire, namely ZHF, ZF, ZFE, PTFF, PF, PGF, PFF, PGFF, SF-2, SFF-2, TFN, TFFN, RFHH-2, RFHH-3, RFH-2, FFH-2, TF, or TFF.

While that list includes some insulation types not listed in 725.49(B), they seem to be better versions of insulation types that are listed, and would so qualify.

Cheers, Wayne