Review Wiring Regulations; Conduit Hub Installation - Mettler Toledo IND780 Guia De Instalacion

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 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 the safest installation possible that meets 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. This will require
removal of the existing power cord and installation of approved hardware such as increased safety
glands or conduit hubs. When new hardware connections are added to the IND780 enclosure, the
connections must maintain the integrity of the sealing of the enclosure.
2.1.1.

Conduit Hub Installation

It is recommended that the AC power be supplied to the terminal using a 1/2" or 3/4" conduit hub
by making a hole in the upper part of the enclosure near the power supply using an appropriately
sized chassis punch. Keeping the AC power entry near the internal power supply will help minimize
electrical interference. The centerline of the hole should be approximately 2" from the top edge of the
enclosure and 1
the conduit hub instead of the supplied cable gland, the original enclosure opening for the power
cord should be sealed with the 16 mm hole plug included with the terminal's standard bag of parts
(#64057809) to maintain the sealing integrity of the harsh enclosure.
2-2 METTLER TOLEDO IND780 Division 2 and Zone 2/22 Installation Guide
THE IND780 TERMINAL IS NOT INTRINSICALLY SAFE FOR USE WITHIN AREAS CLASSIFIED
AS HAZARDOUS DIVISION 1 OR ZONE 0/1 OR ZONE 20/21 BECAUSE OF COMBUSTIBLE OR
EXPLOSIVE ATMOSPHERES. FAILURE TO COMPLY WITH THIS WARNING COULD RESULT IN
BODILY HARM AND/OR PROPERTY DAMAGE.
7
/ " from the outside edge of the power supply side of the enclosure. When using
8
Figure 2-1: Conduit Hub Installation, Harsh Enclosure
WARNING
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