Discrete I/O Relay Option; Temperature Rating; Division 2 Application Example Using Load Cells - Mettler Toledo IND780 Guia De Instalacion

All inputs and outputs to the IND780 terminal not listed in the section above as non-incendive must
be treated as incendive.
2.4.

Discrete I/O Relay Option

An arcing or sparking device cannot be used inside the Division 2 or Zone 2/22 hazardous area
without use of a properly rated enclosure or other nationally approved protection. Because the
optional Discrete I/O Relay board contains non-sealed relays, it cannot be installed and used in an
IND780 used within a Division 2 or Zone 2/22 hazardous area.
If discrete inputs and outputs are required, the Discrete I/O Solid State option (Kit number:
64057422, PCB: 22009913, as shown in the control drawing) can be used. It is also possible to
use an ARM100 remote module (#71209352), which must be located in the safe area or inside a
properly rated enclosure. The Discrete I/O Relay option (Kit number: 64057419, PCB 22009911)
MUST NOT BE USED in an area classified as Division 2 or Zone 2/22.
2.5.

Temperature Rating

It is important that the temperature rating of the IND780 terminal be appropriate for the environment
in which it will be used. The IND780 terminal is approved for US and Canada, ATEX and IECEx,
with a temperature rating of T4 (135˚ C) for gas and dust environments. This value must be lower
than the Auto Ignition Temperature (AIT) of the hazardous product in order to be safe. If the AIT of
the hazardous product is lower than the temperature rating of the IND780 terminal, the IND780
terminal MUST NOT BE USED in that environment.
2.6.

Division 2 Application Example Using Load Cells

The following is an example of applying the IND780 terminal in a Division 2 application connecting
a model 2158 Vertex floor scale with 50 feet of load cell cable. The field circuit parameters for all
devices and cables in the load cell line (including the load cells and junction box) must also be
known.
64063214 | 07 | 02/2018
THE INTERNAL #22009911 DISCRETE I/O RELAY OPTION (KIT NUMBER 64057419) MUST
NOT BE USED IN AN IND780 TERMINAL INSTALLED IN AN AREA CLASSIFIED AS DIVISION 2
OR ZONE 2/22. FAILURE TO COMPLY WITH THIS WARNING COULD RESULT IN BODILY HARM
AND/OR PROPERTY DAMAGE.
THE IND780 TERMINAL HAS BEEN APPROVED BY UL (U.S. AND CANADA) WITH A
TEMPERATURE RATING OF T4 (135° C) FOR USE IN HAZARDOUS ENVIRONMENTS. IT HAS
BEEN CERTIFIED FOR ATEX IECEx WITH A TEMPERATURE RATING OF T4 (135° C) FOR GAS
AND DUST ENVIRONMENTS. IT MUST NOT BE USED IN AREAS WHERE THE AUTO IGNITION
TEMPERATURE OF THE HAZARDOUS MATERIAL IS BELOW THIS RATING.
METTLER TOLEDO IND780 Division 2 and Zone 2/22 Installation Guide
WARNING
WARNING
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