Art 800 help

[royschoolfield]

I have a patient care room where we have installed metal flex over 10 ft to above the ceiling for a cat 5 plenum rated cable to connect a DLM Dimming Wall Switch, 1 paddle, w/IR to a remote power pack. The system is listed to be run in metal flex, conduit, and free air in a plenum ceiling. Its also classified as a low voltage system. Specifications below.
https://www.legrand.us/lighting-con...-wall-switch-1-paddle-w-ir-ivory/p/lmdm-101-i

Input voltage: 24VDC from DLM local network

• Current consumption: 5mA
• DLM local network connection: 2 RJ45 ports
• Control button with LED status indicator
• 7-LED dimming level indicator
• Infrared (IR) transceiver
• Hidden configuration button for access to Push n’ Learn
mode
• Operating conditions: for indoor use only;
32-131°F (0-55°C); 5-95% RH, non-condensing
• UL and cUL listed
• FCC part 15 compliant


My question is that I have been rejected due to the cat 5 cable being installed in metal flex. The way I interpret the code is flex requirements are subject to 800 wiring methods and not 250.118 branch circuits. Should it be chapter 8 wiring methods? Don't chapter 8 stand on itself and does not refer to 250.118. Can someone confirm or deny my answers? I have attached the article the inspector is quoting is 250.118. Rember this is a patient care facility. The argument is, the switch could fail and arc to the metal flex.


(6) Listed liquid-tight flexible metal conduit meeting all the

following conditions:

a. The conduit is terminated in listed fittings.

b. For metric designators 12 through 16 (trade sizes
3∕8 through 1∕2), the circuit conductors contained in
the conduit are protected by overcurrent devices
rated at 20 amperes or less.

c. For metric designators 21 through 35 (trade sizes
3∕4 through 11∕4), the circuit conductors contained in
the conduit are protected by overcurrent devices
rated not more than 60 amperes and there is no flex‐
ible metal conduit, flexible metallic tubing, or liquid‐
tight flexible metal conduit in trade sizes metric
designators 12 through 16 (trade sizes 3∕8 through 1∕2)
in the ground-fault current path.

d. The combined length of flexible metal conduit and
flexible metallic tubing and liquid-tight flexible metal
conduit in the same ground-fault current path does
not exceed 1.8 m (6 ft).

e. If used to connect equipment where flexibility is
necessary to minimize the transmission of vibration
from equipment or to provide flexibility for equipment‐
ment that requires movement after installation, an
equipment grounding conductor shall be installed

 

[roger]

See Part VI of 517.

Roger

 

[royschoolfield]

Thank you.
Part VI Communications, Signaling Systems, Data Systems, Fire Alarm Systems, And Systems Less Than 120 Volts, Nominal
In patient care spaces, 517.80 requires that equivalent insulation and isolation to that required for the electrical distribution systems shall be provided for communications, signaling systems, data system circuits, fire alarm systems, and systems less than 120 volts, nominal. Class 2 and Class 3 systems are not required to comply with the grounding requirements of 517.13, to comply with the mechanical protection requirements of 517.31(C)(3)(5), or to be enclosed in raceways unless otherwise specified by Chapter 7 or 8

 

[don_resqcapt19]

Nothing in that system would be covered by any rule in Chapter 8. Any rules outside of Article 517 would be found in Article 725.

 

[hbiss]

My question is that I have been rejected due to the cat 5 cable being installed in metal flex. The way I interpret the code is flex requirements are subject to 800 wiring methods and not 250.118 branch circuits. Should it be chapter 8 wiring methods? Don't chapter 8 stand on itself and does not refer to 250.118. Can someone confirm or deny my answers? I have attached the article the inspector is quoting is 250.118. Rember this is a patient care facility. The argument is, the switch could fail and arc to the metal flex.

Chapter 800 is communications systems and has nothing to do with what you are talking about. Art. 725 would. The inspector cited Art. 250.118 so let's look at that.

250.118 Types of Equipment Grounding Conductors. The
equipment grounding conductor run with or enclosing the
circuit conductors shall be one or more or a combination of
the following:

Even though Art 250 doesn't apply to an Art 725 installation in this instance, my guess is he is wanting the flex to be bonded to ground along with the box you used for the dimmer and at the other end of the run on the remote power pack, which is a good idea. So, is the flex bonded to ground by the connector at the remote power pack?

-Hal

 

[royschoolfield]

No it's not. But by the manufacturer instructions it does not have to be done. It's listed and labeled for this installation.
Thanks Roy

 

[hbiss]

No it's not. But by the manufacturer instructions it does not have to be done. It's listed and labeled for this installation.
Thanks Roy

I know that but convince the inspector- he has the final word. Sometimes it's easier to comply with something minor than to fight.

-Hal

 

[royschoolfield]

This is not really the minor we are talking about 300 different switches. But I agree with you on principle. But when large amount of money is at play you have to address the issue.
Thanks Roy

 

[hbiss]

You might also want to think about 250.2(A)(3) and (4)

(3) Bonding of Electrical Equipment. Normally non–current carrying
conductive materials enclosing electrical conductors
or equipment, or forming part of such equipment, shall be
connected together and to the electrical supply source in a
manner that establishes an effective ground-fault current path.

(4) Bonding of Electrically Conductive Materials and Other
Equipment. Normally non–current-carrying electrically
conductive materials that are likely to become energized shall
be connected together and to the electrical supply source in
a manner that establishes an effective ground-fault current path.

The system is listed to be run in metal flex, conduit, and free air in a plenum ceiling.

While I can't seem to find that spec I don't doubt that you saw it. All they are saying is that it is a CL2 system. But you need to understand that just saying it can be run in flex or conduit is not an instruction on how that flex or conduit needs to be installed. That depends on the NEC and local codes. I would not want to install an ungrounded metal box with a metal framed device and metal cover plate screws and that's what 250.2(A)(3) and (4) addresses.

-Hal