Emerson Process Management 9110-00A Installation In Hazardous Locations, Electrical Conduit Port

using a flat metal bar or similar tool. When replacing the cover, it should be snugged in and not over-tightened. The threads of the cover should also be coated with a layer of anti-seize compound to prevent lockup.

When the cover is removed, the PC board assemblies become accessible (see right view of Figure 2-3). The Termination Board contains the field wiring terminals while the CPU Board contains the option switches. The gear mechanism and feedback potentiometer are also accessible.

2.4.2 Electrical Conduit Port

Two 3/4 in. NPT electrical ports are provided at the lower part of the housing. Either or both ports may be used to bring in signal and supply wiring (left of Figure 2-3). These ports accommodate a standard 3/4 inch NPT pipe thread connection. If a port is not used, it must have a conduit plug installed to maintain the explosion-proof integrity of the unit.

2.5 INSTALLATION IN HAZARDOUS LOCATIONS

Instruments that operate in hazardous locations must adhere to the following rules of safety:

A.All instrument wiring that runs through a hazardous area must be enclosed in metal conduit. The point where the conduit connection meets the unit's housing should be properly tightened to prevent entry of gas or other ignitable substances. Explosion-proof wiring practices must be followed to prevent flashback through the conduit.

B.The cover of the installed unit must be screwed in hand tight and fully seated. The cover must not be damaged and no threads should be stripped.

C.The cover of the unit must never be removed during operation unless the atmosphere is made safe or all electrical power is removed from the instrument.

** Warning **

No maintenance procedures should be performed while the unit is powered and operating in a combustible or explosive environment. If on-site maintenance is a necessity, steps must be taken to make the environment safe (non-hazardous). Otherwise, the instrument must be powered down, unwired, and brought into a safe area. A failure to observe these precautions could result in fire or explosion and injury to persons.

** Safety Note **

For certified instruments, all installation and operating practices must conform to area classification and safety codes as specified by the certifying laboratory. The seal of the certifying laboratory will appear on the instrument data plate along with the model and serial number.

CI-9110 2-5 Installation