Installing the Sensor Assembly Now that you are sure you have the correct parts, have checked the sizing, and have removed any potential dangers from pressure or electric power, you are ready to begin the installation. Here are the steps to follow: 1. If a thermowell is already installed, do not screw in the complete sensor assembly. If the assembly is screwed in as one piece, the sensor may contact the bottom of the thermowell, restricting sheath rotation. When free rotation is restricted, the wires inside the sheath can potentially twist around each other and short out or break. To prevent this, disassemble the union. Screw the nipple section closest to the sensor junction (N2 on Figure 1) into the vessel wall. Then insert the probe through the nipple and half-union into the vessel. Position the probe so that your conduit port is aligned with the conduit. Tighten the union nut. 2. If no thermowell is used, insert the probe to the appropriate immersion depth or to the midpoint of the pipe. In this case, there is nothing to restrict the assembly from turning freely, so you do not have to be concerned with wire twisting. Therefore, you do not have to dismantle the assembly into two pieces unless necessary to permit conduit alignment. 3. If you are using a spring-loaded assembly, the wires to the terminal block on a onepiece assembly should be disconnected from the terminals to prevent wire twisting and breakage within the termination. You may also use a termination head with a removable spring assembly. In this case, remove the internals, including the terminal block, mounting plate and sensor probe as one assembly, screw in the sheath and head, then replace the internals. 4. Once the terminal head is in place, attach the conduit or flex cable to the conduit port. Pull the thermocouple extension wire through the conduit/flex tube into the terminal head or junction box. (A) (B) Figure 3. Spring-loaded assemblies maintain a positive force of the thermocouple or INDUSTRIAL RTD element against the surface to be monitored, either directly against a piece of metal, for example, or the bottom of a thermowell. The standard spring-loaded assembly is a fixed mount (A). The spring-loaded adjustable nipple allows adjustment of the element (B). www.conaxbuf .conaxbuff conaxbuf@conaxbuff 716-684-4500 Fax: 716-684-7 4-7433 1-800-223-2389 · www.conaxbuf falo.com · conaxbuf@conaxbuf falo.com · 716-684-4500 · Fax: 716-68 4-7433 4