Review Wiring Regulations - Mettler Toledo Division 2 IND570 Serie Guia De Instalacion

If the IND570 terminal does not include the approval markings as shown in section 1.3 of this
guide, the terminal cannot be installed in the hazardous area.
2.1.

Review Wiring Regulations

There are many methods that may be used to install properly approved equipment within
hazardous areas. In some cases, the field circuit characteristics (electrical approval data) must be
compared to those of the device connected to make sure the combination is safe. In other
situations, only a confirmation of a certain IP rating, a nominal supply voltage and current and/or
maximum surface temperature may be required to connect the devices.
METTLER TOLEDO claims no expertise with respect to all the electrical regulations that may be in
effect at any specific location. You must refer to a national and/or local electrical standards
handbook for an installation that conforms to all required standards.
Some national standards (including the NEC in the United States) require protection of incendive
lines such as the AC power line or PLC interfaces using conduit or flexible conduit. Models of the
IND570xx that are ordered with the US/Canadian approval will include three conduit fittings
installed. During installation, all connections must maintain the integrity of the sealing of the
enclosure.
Harsh enclosures of the IND570xx ordered with the US/Canadian approval will provide two ¾"
conduit hubs and one ½" conduit hub already installed, as shown in Figure 2-1. All unused hubs
must have an NPT plug installed to maintain the IP rating of the enclosure. AC power is connected
via rigid conduit through the left conduit hub. The power requirements are listed in Figure 2-1.
When wiring AC power to the IND570xx terminal, the wire gage (or cross-sectional area) of the
protective power ground must be equal to or greater than the wire gage (or cross-sectional area) of
2-2 METTLER TOLEDO IND570xx Division 2 and Zone 22 Installation Manual
THE IND570XX TERMINAL IS NOT INTRINSICALLY SAFE LEVEL "A" OR "B"! DO NOT USE WITHIN AREAS
CLASSIFIED AS HAZARDOUS DIVISION 1, ZONE 0/1 OR ZONE 20/21 BECAUSE OF COMBUSTIBLE OR
EXPLOSIVE ATMOSPHERES.
Figure 2-1: Conduit Hub Installation, Harsh Enclosure
WARNING
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