I have taken over the installation of a computer monitor in a class 1 div 1 area. This monitor is rated for such area. The monitor is powered by 120 volts AC. It has a normal monitor power cable running to a 20 AMP twist lock that I believe is still inside the classified location. The previous tech installed a XP cable gland around the power cord. Is this the proper installation? Also, there are CAT5 cables and a VGA cable running to the monitor installed in the same manner. The CAT5 cables are for USB extension for the mouse and the VGA cable is for the display its self. I am new to this type of install and am uncertain that this is the correct way. I am used to installing electrical conduit with seal offs etc... for power installs and not certain where to reference. Keep in mind this is on an offshore platform so I am not certain if the NEC applies.
Requirements for power/data cables in a class 1 div 1
- Thread starter jntexan01
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petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
I don't believe you can use a standard twist-lock receptacle/plug in a C1D1 area.
You might be able to use CAT5 cables as described. There are some systems that have IS barriers for such things.
I don't know what you mean by "rated for such area". Is it in an XP housing? Or a pressurized/purged housing?
Overall, based on what you are saying I am suspicious of what was done, but depending on the exact details it might be possible the install is to code.
If the spec says it is C1D1, that generally would indicate it is a NEC environment.
It might be best to go back to whomever engineered this thing and get their input rather than the input from a bunch of random guys on the Internet.
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
I have to concur with petersonra; the installation is incredibly suspicious, as you have described it. In fact, since you made no mention of intrinsic safety, all of the various cables you have described would only be permitted to be installed in threaded metal conduits regardless of their purpose. [Section 501.10(A)(1)(a)]
The monitor has a listing for all classified areas. It is a Hope Industrial monitor. I am certain the cord and plug being used for power is not listed for use in this area. I will double check on the receptacle location as it may be outside the classified area. Although I would say a power cable running outside a threaded raceway would fall outside the approved use. Also the Cat5 cables are not PLTC rated that I am aware of. I am currently checking on their listing. I may be opening up a can of worms here but it needs to be installed correctly.
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