Assessments - 2, GPA: 5
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A 1/4 inch NPT vent is provided on the pressure regulator body for this purpose. The vent location is shown in Figure 2-3. When air is used as the pressure source, the vent fitting may be allowed to bleed into the atmosphere. If fuel gas or other hazardous type gases are used as the pressure source for a Remote Set Regulator, the VENT port must be piped to a safe location. ** Warning ** Covers of Remote Set Regulators operating in hazardous areas should not be removed. If servicing is required, the environment should first be made safe or the supply power should be turned off, allowing the instrument to be disconnected and removed to a safe area. Figure 2-3 - Typical Pressure Connections 2.4 INTERNAL ACCESS The subtopics that follow discuss the main mechanical and electrical assemblies that will be accessed during installation. They describe the method of removing and installing the cover, the use of the electrical conduit ports, and the installation precautions to be observed. 2.4.1 Body and Cover The Remote Set Regulator is contained in a aluminum body with a gasketed screw-on cover as shown in Figure 2-2. Four raised lugs on the cover permit it to be loosened or tightened CI-9110 2-5 Installation 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 3-1 Board Setup Chapter 3 BOARD SETUP 3.1 USING OPTION SWITCHES Two switch assemblies (SW1 and SW2) are used to set options and select ranges. These switches are located on the CPU Board as shown in Figure 3-1. Each assembly contains eight (8) miniature SPST switches. The individual switches of each package are identified as subsets of the main switch, e.g., SW1-1, SW1-2, etc. Two types of switch assemblies are used for Regulators. One type uses cradle switches, while the other uses slide-type switches. The operation of each type differs as follows: Cradle Switches with OPEN Designation: OPEN side pressed down = OFF (open circuit) Numbered side pressed down = ON (closed circuit) Slide Switches with ON Designation: Set in direction of ON arrow = ON (closed circuit) Set in opposite direction of arrow = OFF (open circuit) The switch assemblies are fragile and require careful handling. Use a small, blunt object such as a miniature screwdriver to set the switch positions. Do not use pencils, ballpoint pens, or extremely sharp objects for this purpose. WARNING When starting a unit for the first time, all switch options must be set before any power is applied. Improper switch settings can cause improper operation or dangerous control situations that could damage process equipment and property, or cause injury to persons. NOTE Attempting to change settings of any switch (e...
Este manual também é adequado para os modelos :Os termostatos - Bristol 9110-00A (3.95 mb)
Os termostatos - Bristol Series 9110 (3.95 mb)