4
Non-Metallic Ducts:
If the
Dust
Alarm
®
ES
is to be mounted in a non-metallic pipe or
duct, the following special precautions must be taken to prevent
the detection of stray electric fields:
1) Light Dusting
- If the unit is to be installed after a dust col-
lector where only a light dust loading is present, an electro-
static (Faraday) shield must surround the pipe or duct for
a distance equal to three times the duct diameter both up
and down stream. The shield must make contact with the
external ground screw on the
Dust
Alarm
®
ES
and a reliable
earth ground. Hardware cloth, screen material or rabbit
wire are satisfactory shield material.
2) Heavy Dusting
- If a heavy dust loading is present, the unit
must be installed in a section of metallic pipe or duct. This
section should extend as far up stream as possible or down
stream for a distance equal to two times the duct diameter
and must be connected to a reliable earth ground.
NOTE:
The
Dust
Alarm
®
ES
mounting must be provided with
ELECTRICAL INSTALL ATION
1) Hazardous Location Precautions
- Observe the regulations
listed in the NEC (USA) or CEC (Canada) and all others with site juris-
diction regarding equipment in hazardous locations when installing the
hazardous location models of the
Dust
Alarm
®
ES
sensor in hazardous
classified locations. Wiring and all installation methods must be per-
formed according to the authority having site jurisdiction and is the sole
responsibility of the installer to ensure such.
Haz-Loc Versions: External circuits connected to RELAY-1 & RELAY-2
terminals shall be provided with fuses conforming to the IEC 60127 series and
UL 248 series. Fuses shall be rated for 5A max, 250VAC or 30VDC.
Ensure power is disconnected from the sensor, or the area has
been cleared of hazardous conditions before the cover is removed. A
locking mechanism on the back of the enclosure is provided to prevent
removal of the cover without the use of a tool.
Electrostatic charges:
The equipment shall not be installed in a location where the external condi-
tions are conducive to the build-up of electrostatic charges.
l
Avoid all materials which could be capable of generating electrostatic
charges at the installation location
l
The equipment shall only be cleaned with a damp cloth and allowed to dry
l
Make sure that the equipment is properly connected to a stable ground
potential either at the external or internal grounding connection
It is important to note that the hazardous location models are
certified with two protection concepts: The probes and wires from the
probes to the sensing electronics board within the enclosure are an
intrinsically safe circuit. The enclosure and main electronics within are
not intrinsically-safe; Therefore, protection is by dust-ignition proof
enclosure. One conduit entry is provided with a metallic plug, factory
installed. This plug (blanking element) cannot be substituted or
replaced with other than that acquired from the factory.
Conduit fittings must be rated IP64 minimum for hazardous locations-only.
2) Factory Wiring
- The probe wires internal to the housing are connected
to the front side of the PCB.
DO NOT
alter this connection. Doing so will
likely cause improper operation or permanent damage to the device.
3) Permanently Connected Equipment
- Disconnecting devices shall
be included in the system installation. In installations where multiple cir-
cuits are used (i.e. independent circuits for power input and relay out-
put), individual disconnects are required. The disconnects shall be with-
in close proximity of the equipment, accessible to operators, and marked
appropriately as the disconnect for the associated circuit. Ensure the
disconnect ratings are appropriately sized to the circuit protected (See
Specifications). The MAINS power that connects to the sensor MUST
provide circuit protection and NOT exceed 20A total.
4) Disconnects Separation
- It is recommended to span from
the disconnects to the sensor with a long enough section of
flexible conduit that will allow the probe to be removed from
ducting for easy inspection and cleaning.
5) Circuit Separation
- Two cable/conduit entry locations are
provided to aid in maintaining separation of “hazardous live”
(typical mains voltages such as 115VAC or 230VAC) and limited cir-
cuits (typically control voltages less than 30Vrms or 42.5VDC). It is
required that all wiring used must have an insulation rating of 300v
minimum, and a temperature rating of 221˚F (105˚C) minimum.
2) Vibration
- The unit is designed for use in conjunction with
baghouse and dust collector systems. As such it is provided
with a rugged cast aluminum enclosure. However, care
should be taken to protect the unit from excessive vibration,
which can cause physical damage to the electrical circuit
boards and connections.
3) Temperature Limits
- The operational temperature limits must
be maintained to ensure reliable operation (See Specifications).
Enclosure surface temperature is dependent on the process
temperature. At a process temp of 200
o
C and the enclosure
housing & the electronics outside of the process, the maximum
enclosure surface temp "T" rating of 85
o
C applies.
4) Other Location Considerations
- The location should be a
sufficient distance from the stack exit so that outside atmospheric
conditions will not affect the sensor. For example, heavy rain may
cause a false signal if the sensor is located in a vertical stack.
MECHANICAL INSTALL ATION
The
DustAlarm
®
ES
mounts to a tri-clamp quick-disconnect fer-
rule (also available from Monitor Technologies) that has to be
installed into the air duct for easy installation and maintenance of
the sensor. The ferrule is typically welded to the duct. Be sure to
remove the gasket and clamp from the ferrule before welding.
Also before welding, ensure that when the
DustAlarm
®
ES
sensor
is installed such that the probe insulator protrudes into the duct at
least 0.75” [19mm] and is exposed to airflow. (See Figure 3).
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Figure 3
a local earth ground, either through the duct-work and
Dust
Alarm
®
ES
mounting or by a separate means connected
to the mounting. The safety (protective earth) ground is
provided through the electrical power supply connection.
Test Port:
For negative pressure systems, to aid in troubleshooting, it is recommend-
ed that a test port be installed upstream from the sensor as a means to
inject sample dust material. The port’s distance from the sensor should be
approximately equal to two times the duct diameter and on the same side
of the duct. A plugged half coupling is sufficient.
Failure to correctly install the
Dust
Alarm
®
ES
may prevent the unit from
operating reliably; therefore, any modifications to these procedures
should be discussed with the factory.
DIMENSIONS ARE SHOWN IN INCHES WITH MILLIMETER EQUIVALENT IN BRACKETS
(Suggested Min. 0.75” [19mm])
(Recommended)
