Dwyer DPM - Manual (Page 17)

Particulate Monitoring Systems
Installation & Operating Manual
Document No. 210-1003-M Page 10 ©2007
5. Particulate Sensor Coaxial Cable Installation
Connection: Prior to making coaxial cable connections review the following routing instructions.
_ PARTICULATE SENSOR COAXIAL CABLE ROUTING
• The sensor cable must be installed in conduit that is separate from all other
wiring.
• The cable should be routed from the particulate sensor to the control unit in
a path that avoids high vibration, heat over 394
°F (200°C) and any strong
magnetic or electrical fields.
• The cable should be located at least 18 in (46 cm) away from any power
lines (conduit), motors, frequency drives and other sources of electrical
interference throughout its entire path.
• The cable should be installed in metallic conduit. At the process end, use a
section of shielded flex conduit that is 1 to 2 times the probe length to serve
as a service loop.
The coaxial cable is connected to the control unit by a coax connector and is connected to the sensor
by two ring terminals. The connectors are normally supplied pre-assembled to the cable.
Once the cable has been routed, insert the coax connector into the control unit enclosure leaving a
very small service loop as specified in the installation drawing shown in the appendix. A larger
service loop should be used at the sensor end, typically 1 to 2 times the sensor length. Any small
amount of extra cable length should be pulled into the nearest junction box and NOT left in the sensor
housing or in the control unit enclosure. If there is a significant amount of extra cable (many feet), the
cable should be shortened at the sensor end and the sensor end connectors should be re-assembled
using factory-supplied connectors and instructions.
_ COAXIAL CABLE INSIDE THE CONTROL UNIT
• A ferrite suppressor is located on the sensor coaxial cable near the coax
connector and must remain inside the control unit enclosure.
• The black cable insulation must extend a minimum of 6 in (15 cm) into the
coax cable conduit.
• Do not leave any excess cable in the control unit or sensor housing.
Inside the particulate sensor enclosure, attach the coax cable as indicated in the sensor drawing. When
connecting the braided shield, ensure it does not touch the surge voltage protection assembly. Do not
leave excess cable inside the sensor housing.
IMPORTANT
IMPORTANT