Lightning Protection; Supply Voltage Limiting Requirements; Process Sealing; Explosion-Proof Conduit Seal - Honeywell ST 700 User Manual

4.6.5 Lightning Protection

If your Transmitter includes the optional lightning protection, connect a wire from the Earth Ground
Clamp (see Figure 15) to Earth Ground to make the protection effective. Use a size 8 AWG or
2
(8.37mm ) bare or green covered wire for this connection.

4.6.6 Supply Voltage Limiting Requirements

If your Transmitter complies with the ATEX 4 directive for self-declared approval per 94/9EC, the
power supply has to include a voltage-limiting device. Voltage must be limited such that it does not
exceed 42V DC. Consult the process design system documentation for specifics.

4.6.7 Process Sealing

The ST 700 SmartLine Pressure Transmitter is CSA-certified as a Dual Seal device in accordance
with ANSI/ISA–12.27.01–2003, "Requirements for Process Sealing Between Electrical Systems and
Flammable, or Combustible Process Fluids."

4.6.8 Explosion-Proof Conduit Seal

When installed as explosion proof in a Division 1 Hazardous Location, keep covers tight
while the Transmitter is energized. Disconnect power to the Transmitter in the non-hazardous
area prior to removing end caps for service.
When installed as non-incendive equipment in a Division 2 hazardous location, disconnect
power to the Transmitter in the non-hazardous area, or determine that the location is non-
hazardous before disconnecting or connecting the Transmitter wires.
Transmitters installed as explosion proof in Class I, Division 1, Group A Hazardous (classified)
locations in accordance with ANSI/NFPA 70, the US National Electrical Code, with 1/2 inch conduit
do not require an explosion-proof seal for installation. If 3/4 inch conduit is used, a LISTED
explosion-proof seal to be installed in the conduit, within 18 inches (457.2mm) of the Transmitter.
Revision 8.0
ST 700 SmartLine Pressure Transmitters User's Manual
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