1 ac mains electrical power connection, 2 low voltage dc powered option - electric, 2 sensor connection – COSA Xentaur Xentaur XDT User Manual

Page 20: 3 wiring the alarm contacts

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Section 3: Instrument

13

fast acting fuse. Please follow the appropriate installation procedures in the paragraphs below
according to the electrical power option on your instrument. Do not connect to AC power without
a proper ground connection.
For Intrinsically Safe installations, first make sure that the equipment is qualified for the particu-
lar installation, it should have a label specifying the certifications and the approving agency. Then
follow the appropriate control drawing as well as the instructions in the relevant paragraphs in this
manual.

3.3.2.1.1 AC Mains Electrical Power Connection

The XDT is provided with a 6 foot (2 meter) internationally approved AC power cord, terminated
with a connector according to the ordered option. This cable is connected to the pluggable screw
terminal block; however it is provided strictly as a means of testing the instrument, it should not
be used in the final installation
. The XDT is intended as a field wired instrument permanently
connected and installed according to the local, nationally recognized procedures for equipment of
this type and stated power requirements. For North American installations use UL 62 and/or CSA
C22.2 No 49, 18AWG cable with black, white, and green color codes. For European and other
international installations use CENELEC harmonized type cable, with 0.82mm wire size or
equivalent 10 amp use, with brown, light blue, and green/yellow stripe color codes. The power
wiring must be connected to the pluggable screw terminals marked AC LIVE (#1), AC NEU-
TRAL (#2), and AC GROUND (#4). A switch or circuit breaker shall be included in the installa-
tion. It shall be in close proximity to the equipment and within easy reach of the operator. It shall
be marked as the disconnecting device for the instrument. For the XDT-NEMA use the 1/2” NPT
conduit fitting as the power cable access, do not use the cable grips they are for low voltage use
only.

3.3.2.1.2 Low Voltage DC Powered Option - Electrical Power Connection

When an XDT is configured with the low voltage DC power option, it can be powered by apply-
ing 15 to 30 VDC 0.5A, to the PS+ (#12) and RET (#11) pluggable screw terminals. The positive
supply must be connected to PS+, while the negative or ground to RET. The AC terminals must
not be connected. Note that the DC supply is ground referenced to the analog output and RS-232
grounds.

3.3.2.2 Sensor Connection

The sensor input terminals are labeled “SIG-IN” (#5) for the center core of the coaxial sensor
cable, and “SIG RET” (#6) for the outside braid of the cable. Factory supplied coaxial cables have
a BNC connector at one end to mate to the sensor, and pigtails at the other end to be placed in the
screw terminals of P1, the black pigtail is the braid and should be connected to the terminal
marked “SIG RET”. The coaxial cable should not exceed 17,000 pF, if the cable is changed for a
longer or shorter one the instrument must be compensated for the new cable (see section 3.4.5 -
11). The instrument is properly compensated for the cable supplied from the factory. Consult
your representative for obtaining the proper cable.

3.3.2.3 Wiring the Alarm Contacts

The optional alarm relay contacts are located on the terminal strip P1. The terminal strips are
marked to indicate wipers and normally open and normally closed contacts, of the two indepen-

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