Conduit Seal And Pressure Relief - ABB 3000 Series Instruction Manual

10DS3111A INSTRUCTION MANUAL

2.7 Conduit Seal and Pressure Relief

In accordance with the National Electrical Code (NEC) ANSI/NFPA 70, Article 501-5(f)(3), the
flowmeter includes a conduit entry seal and pressure relief to prevent the process liquid from entering
the electrical conduit system. This safety feature considers the remote possibility of a primary seal
failure between the meter body and the electronic housing.
The conduit entry seal will prevent the process liquid from entering the electrical conduit system. The
conduit entry seal consists of a conduit entry cable seal on the meter junction box. It is the user's
responsibility to properly install the conduit entry cable seal fitting supplied with the signal converter
interconnection cable. This will ensure proper performance of this safety feature. Refer to Figure 2-9.
A pressure relief is provided in the electronics housing for the meter. The pressure relief is located in
the center of the cover joint on the side opposite from the conduit connection. If the primary seal
should fail, the pressure relief will vent the process preventing an over pressurization and potentially
dangerous failure of the electronics housing. It is the user's responsibility to be aware of this safety
feature and to consider the unlikely event of its functioning. Based on knowledge of the process and
meter application, the user should consider the use of deflectors to safely direct the vented process.
FIGURE 2-10. CONDUIT ENTRY SEAL INSTALLATION
2-12