Incendive Signal Lines - Mettler Toledo IND780 Guia De Instalacion

2.1.2.

Incendive Signal Lines

PLC and other incendive signal lines can be supplied to the terminal using a 1/2" conduit hub
installed directly in the opening for either large cable plug. If a larger 3/4" hub is preferred, it can be
installed by enlarging one of the large cable plug positions. Refer to Figure 2-1 for an example of
the installation of a 3/4" conduit hub for AC power and a 1/2" conduit hub for the incendive signal
lines.
To provide AC power to the harsh terminal, the power cord may be routed through an increased
safety gland (supplied) or a conduit hub installed on the enclosure. If longer distance wiring is
required, make a splice connection to the power cord outside the terminal's enclosure. Refer to the
national and local electrical standards on power wiring and termination requirements in the Division
2 and Zone 2/22 environment. When wiring to the harsh terminal, the gage (or cross-sectional
area) of the protective power ground must be equal to or greater than the gage (or cross-sectional
area) of the power phased connectors. The power phased connectors (neutral and line) shall be a
minimum of .9mm
2.1.2.1. Power Cord Notes for US/Canada
It is possible to use a power cord that conforms to NEC 501.105(B)(6) Flexible Cord for certain
installations, provided that:
•
•
•
Refer to NEC 501.105(B)(6) for complete requirements.
Figure 2-2 shows the harsh terminal as shipped, with unterminated power cord.
64063214 | 07 | 02/2018
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(size 18awg) and a maximum of 3.6mm
FOR CONTINUED PROTECTION AGAINST EXPLOSION AND ELECTRIC SHOCK, THE IND780 MUST
BE GROUNDED TO PROTECTIVE EARTH. FOR HARSH UNITS, ENSURE YELLOW AND GREEN WIRE
FROM POWER SOURCE IS SECURELY CONNECTED TO PROTECTIVE EARTH. ENSURE
PROTECTIVE EARTH IS SECURELY CONNECTED TO THE PROPER CONNECTOR POSITION ON THE
PANEL MOUNT UNIT.
The cord is equipped with a locking plug
There is a power switch at the socket
The cord's maximum length is 3 feet. (The supplied 6 foot cord must be trimmed in order to
conform.
METTLER TOLEDO IND780 Division 2 and Zone 2/22 Installation Guide
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(12awg) stranded wire.
WARNING
2-3