Seals; Sensor Separation - Emerson Net Safety Millennium Reference Manual

Installation
NOTICE
Wiring codes and regulations may vary. ATEX requires that supply connections wiring must be
rated at least 41 °F (5 °C) above the maximum ambient temperature of 185 °F (85 °C ). Wiring
must comply with all applicable regulations relating to the installation of electrical equipment
in a hazardous area and is the responsibility of the installer. If in doubt, consult a qualified
official before wiring the system.
When separating the sensor from the transmitter, the use of shielded cable is highly
recommended to protect against interference caused by extraneous electrical or
electromagnetic noise to meet mandatory CE mark electromagnetic compatibility (EMC)
requirements. In applications where the wiring is installed in conduit, the conduit must not
be used for wiring to other equipment.
2.5.2

Seals

The use of seals is recommended to further protect the system against any unwanted
water ingression, and equipment should be installed according to applicable local
electrical codes. Seals are especially recommended for installations that use high-pressure
or steam cleaning devices in proximity to the transmitter and/or sensor.
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2.5.3

Sensor separation

Since the APM Sensor must be located where it will pick up particulate in an air flow, and
the transmitter where it can be easily reached, it is often necessary to separate the
transmitter and sensor. This is done with the aid of the included sensor separation kit
(SEP). This kit is composed of a junction box and terminal strip. Refer to the Net Safety
Multi-purpose Junction Box manual (MAN-0081) for terminal designation.
10
Water-proof and explosion-proof conduit seals are recommended to prevent water
accumulation within the enclosure.
Seals should be located as close to the device as possible and not more than18
inches (46 cm) away.
Explosion-proof installations may require an additional seal where conduit enters a
non-hazardous area. Ensure conformity with local wiring codes.
When pouring a seal, use a fiber dam to assure proper formation of the seal. Seals
should never be poured at temperatures below freezing.
The jacket and shielding of the cable should be stripped back to permit the seal to
form around the individual wires. This will prevent air, particles, and water leakage
through the inside of the shield and into the enclosure.
It is recommended that explosion-proof drains and conduit breathers be used. In
some applications, alternate changes in temperature and barometric pressure can
cause breathing which allows moist air to enter and circulate inside the conduit.
Joints in the conduit system are seldom tight enough to prevent thisbreathing.