# class 1, div2



## Mountain Electrician (Jan 22, 2007)

sparky970 said:


> I am installing conduits from cable tray outside the classified to an instrument in a Class 1, Div. 2 area. One conduit is for 120vac power and the other is the signal wire from the pH transmitter. The cable tray is outside the classified boundary. Do I need some type of seal-off or will CGB's be sufficient? The conduits that end in the classified area are connected to the instrument with sealtite and listed fittings. Any suggestions? Also, when it is time to calibrate these probe, they must be removed from the process. While the voltage potential is in the mV range, would it be against the Code to expose them to a potentially hazardous atmosphere? Thanks


You don't need a seal at the classification boundary as you are running the conduit to a cable tray,[Art.500.15(B)(2)Ex.2] but you need one at the transmitter if it's in an explosionproof enclosure.[Art.500.15(B)(1)]

As far as instrument calibration, that should be mandated by the facilities safety guidelines. A work permit should list job specific hazards and safety considerations.


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