Question about flex cord per 501.140

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batese

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Does anyone have any experience using flex cord in accordance with section 501.140 of the NEC? In particular I am looking to use flexible fieldbus (RS-485) cable in a C1D1 location but have not had any luck in understanding what cable would be acceptable/suitable. Is there a special cable for 501.140 that I should be looking into? I found some good information about MC-HL, ITC-HL and TC-ER-HL cables for haz loc, but I was not able to find much information for cabling acc to 501.140. Any help would be much appreciated.
 
batese said:
In this case, I think that section 501.140(A)(2) would apply.
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OK.

Section 501.140 (B) (1) requires the cord be of a type listed for extra-hard usage; I.e., referenced as such in Table 400.4. To my knowledge, no RS-485 cable meets the requirement, mainly because it isn’t a cord.

At this point you would need to appeal to Section 500.8(A)(3) and have a manufacturer validate a cable is or could be NRTL dual certified as a Table 400.4 extra-hard usage cord.
 
I think you can use any cable you want in conduit because there is no way to terminate it that would be compliant otherwise. Maybe you could use IS barriers.

A lot of detailed information about what you really want to do would be required to determine a solution.
 
batese said:
Does anyone have any experience using flex cord in accordance with section 501.140 of the NEC? In particular I am looking to use flexible fieldbus (RS-485) cable in a C1D1 location but have not had any luck in understanding what cable would be acceptable/suitable. Is there a special cable for 501.140 that I should be looking into? I found some good information about MC-HL, ITC-HL and TC-ER-HL cables for haz loc, but I was not able to find much information for cabling acc to 501.140. Any help would be much appreciated.
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We typically use 2-pair okanite with TMCX connectors for RS-485 in CID1. The one pair is for the A- / B+ and then use the black from the other pair for ground.
 
TwoBlocked said:
We typically use 2-pair okanite with TMCX connectors for RS-485 in CID1. The one pair is for the A- / B+ and then use the black from the other pair for ground.
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Do they make a cable with the correct impedance?

The OP used the term fieldbus in his post. That suggests something other than run if the mill RS485 to me.

In any case, I don't see how a cable can be subbed in as a cord. You would need to run it in conduit or a tray cable.
 
TwoBlocked said:
We typically use 2-pair okanite with TMCX connectors for RS-485 in CID1. The one pair is for the A- / B+ and then use the black from the other pair for ground.
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What is the part number of the okanite cable that you use in C1D1? Is it twisted pair, with 120 ohm resistance?
I wish the client would use hard pipe with seals, but in this case, it floods regularly, and they believe (through experience) that hard conduit is basically a hose that expels into the devices. Attached is an example of the application, its basically an XP electric actuator in a pit, connected to the remote mounted controls via flex XP cables with Hawke 753 conduit seals. Bear with me, I am drawing it in paint, the purple cable is the one I am having trouble finding.
 

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petersonra said:
Do they make a cable with the correct impedance?

The OP used the term fieldbus in his post. That suggests something other than run if the mill RS485 to me.

In any case, I don't see how a cable can be subbed in as a cord. You would need to run it in conduit or a tray cable.
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Sorry, fieldbus to most is considered foundation fieldbus. I considered the fieldbus in this case to be CANbus/RS485.
 
So basically, it seems like there is not an extra hard usage cable available on the market for CANbus/RS485 cable. Even type ITC-HL, MC-HL, TC-ER-HL and SOOW cables are not available for my exact application in the form of CANbus. I was however able to find FFbus and Profibus DP cable available with C1D1 ratings, but it appears that not all of the bus flavors are available with C1D1. We are now switching gears, and possibly moving to an all hard-wired version (without CANbus). I was able to find a SOOW cable (see below), but it does not mention anything about C1D1 on the website. Is all SOOW cable approved for C1D1? I reached out to the manufacturer, and they said they can answer my questions until I place a PO first, which is crazy to me...
www.awcwire.com

SOOW 18/16 Shielded SOOW Service Cord | Allied Wire & Cable

Customizable 18 16 SOOW shielded cord is an 18 AWG cable with 16 tinned copper conductors with EPDM insulation in a tough CPE jacket that withstands the elements
www.awcwire.com www.awcwire.com
 
petersonra said:
Do they make a cable with the correct impedance?

The OP used the term fieldbus in his post. That suggests something other than run if the mill RS485 to me.

In any case, I don't see how a cable can be subbed in as a cord. You would need to run it in conduit or a tray cable.
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I think the Okanite cat number is 564-60-3402. The general spec sheet I found does not list the impedance. It's what they give me, what I install, and what works.
 
batese said:
So basically, it seems like there is not an extra hard usage cable available on the market for CANbus/RS485 cable. Even type ITC-HL, MC-HL, TC-ER-HL and SOOW cables are not available for my exact application in the form of CANbus. I was however able to find FFbus and Profibus DP cable available with C1D1 ratings, but it appears that not all of the bus flavors are available with C1D1. We are now switching gears, and possibly moving to an all hard-wired version (without CANbus). I was able to find a SOOW cable (see below), but it does not mention anything about C1D1 on the website. Is all SOOW cable approved for C1D1? I reached out to the manufacturer, and they said they can answer my questions until I place a PO first, which is crazy to me...
www.awcwire.com

SOOW 18/16 Shielded SOOW Service Cord | Allied Wire & Cable

Customizable 18 16 SOOW shielded cord is an 18 AWG cable with 16 tinned copper conductors with EPDM insulation in a tough CPE jacket that withstands the elements
www.awcwire.com www.awcwire.com
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That is ALWAYS my preference. You can't troubleshoot comm problems with a meter.
 
TwoBlocked said:
I think the Okanite cat number is 564-60-3402. The general spec sheet I found does not list the impedance. It's what they give me, what I install, and what works.
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It would probably work if you ran two chunks of THHN. For short distances, lower speeds, and few stations a lot of the cable specs don't matter all that much.
 
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