Hach IO9004 User Instructions page 9

Electrical installation
Electrocution hazard. Always remove power to the instrument before making electrical connections.
Electrocution hazard. Use only fittings that have the specified environmental enclosure rating. Obey the
requirements in the Specifications section.
Electrical shock hazard. Externally connected equipment must have an applicable country safety
standard assessment.
Make sure that the equipment is connected to the instrument in accordance with local, regional and national
requirements.
• Use cables with a diameter of 4.3 to 11.4 mm (0.17 to 0.45 in.) so that the cable strain reliefs hold
the cables when tightened.
• Do not put more than one cable in a cable strain relief.
• To connect conduit to a terminal, replace an installed cable strain relief with a conduit fitting. To
connect conduit to the I/O module, replace the applicable cable strain relief with a sealing conduit
to bond the conduit to the bonding plate of the I/O module. For a reliable, low impedance ground
connection, an independent ground wire with equivalent gauge can be pulled and attached at the
ground lug terminal on the bonding plate.
• Close all unused cable strain reliefs with rods, cables or the supplied sealing cords to keep out
moisture.
• For relay connections, it is necessary to use a 20 A circuit breaker (at maximum). Relay
connections must have a local disconnection device. The disconnection device must clearly
identify that this device is the disconnection device. Make sure that the device is in a location
where there is sufficient clearance around it to make connections and to do maintenance tasks.
D A N G E R
D A N G E R
W A R N I N G
N O T I C E
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