Discrete I/O Relay Option; Temperature Rating; Division 2 Application Example Using Load Cells - Mettler Toledo Division 2 IND570 Serie Guia De Instalacion

2.6.
2.7.
2.8.
Note: There are many
methods that may be used to
install properly approved
equipment within hazardous
areas. In our example, the
non-incendive field circuit
parameters (electrical
approval data) were
compared to those of the load
cells connected to make sure
the combination is safe. In
other applications
(specifically in Europe), only
a confirmation of a certain IP
rating and maximum surface
temperature may be required
to connect the devices.
2-8 METTLER TOLEDO IND570xx Division 2 and Zone 22 Installation Manual

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 nationally approved protection methods. Because the optional Discrete I/O Relay
board contains non-sealed relays, it cannot be installed and used in an IND570xx.
If discrete inputs and outputs are required, the solid state version of the discrete I/O may be used
within the hazardous area or the remote ARM100 (#71209352) can be used but it must be
located in the safe area or inside a properly rated enclosure.
THE INTERNAL DISCRETE I/O RELAY OPTION #30113540 OR 30113542 MUST NOT BE USED IN AN
IND570XX TERMINAL. FAILURE TO COMPLY WITH THIS WARNING COULD RESULT IN BODILY HARM
AND/OR PROPERTY DAMAGE.

Temperature Rating

It is important that the temperature rating of the IND570xx terminal be appropriate for the
environment in which it will be used. The IND570xx terminal has been approved with a temperature
rating of T5 (100˚C) for gas and a maximum surface temperature rating of 85˚C for dust. 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 IND570xx
terminal, the IND570xx terminal MUST NOT BE USED in that environment.
THE IND570XX TERMINAL HAS A TEMPERATURE RATING OF T5 (100° C) FOR GAS AND A MAXIMUM
SURFACE TEMPERATURE RATING OF 85° C FOR DUST. IT MUST NOT BE USED IN AREAS WHERE THE
AUTO IGNITION TEMPERATURE OF THE HAZARDOUS MATERIAL IS BELOW THIS RATING.

Division 2 Application Example Using Load Cells

The following is an example of applying the IND570xx terminal in a Division 2 application
connecting a model 2158 Vertex floor scale with 50 feet of load cell cable. The non-incendive field
wiring circuit (NIFW) parameters for all devices and cables in the load cell line (including the load
cells and junction box) must also be known.
Terminal model: IND570xx terminal
Load cell model: METTLER TOLEDO 0745A
Quantity of load cells: 4
Load cell cable length: 50 feet
Junction box Model: AJB641SX
WARNING
WARNING
Base model: 2158 VERTEX
®
(with approved cells)
30205321 | 02 | 05/2017