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2.3
ELECTRICAL CONNECTIONS
1.
Verify/configure the input power. The input power requirement is listed on the tag on
the transmitter enclosure. Be sure the input power source to be used is properly selected
in the unit. Unless specifically ordered otherwise, the input power requirements are
24±2Vdc @ 0.25A typical.
Do not apply power to the instrument until all connections
are made and all enclosure covers are in place.
!! CAUTION
: Use supply wires suitable for 10̊C above ambient.
!! CAUTION
: The output signal is isolated from the power ground. If you
are connecting the 4-20 mA output to an isolated input device, it may be
advisable to ground the incoming signal at the input device. Refer to the input
device manufacturer’s recommendations.
2. Check the analog output configuration of the transmitter and your input device.
Typically the 4-20 mA output is configured to actively supply the loop current. If
another output type has been ordered it will be listed in SECTION 6.3 - SPECIAL
INSTRUCTIONS. (Active: current to the loop is sourced by transmitter. Passive: output
receiver sources the current.)
3. Pull wires through the conduit. Wire for the power connection must be no smaller than
22 gauge or as required by applicable local or company wiring codes. After pulling the
wire, pot the conduit or wires near the enclosure if there is any possibility of water from
condensation or spray entering the enclosure through the conduit. With the “blind”
option, a single cable that contains two internal twisted-shielded pairs is included and is
used for both the input power and the output signal.
!! WARNING
: The transmitter unit is not protected against condensed liquid water
inside the enclosure. Be sure conduit interfaces are dry or sealed at the instrument to
prevent condensation that may be present in conduit lines from entering the enclosure.
4. Make wiring connections.
Power should be off at this time
.
!! WARNING
: Verify the wiring. The equipment can be permanently damaged if not
wired as instructed in this manual. Applicable code requirements should also be met
when connecting the conduit to the enclosure.
5. Secure the enclosure cover(s). Make sure it is tight enough to make a good seal against the
gasket if supplied, and ensure all other enclosure openings are completely watertight
6. Connect functional ground. To assure EMC compliance, ground the sensor and the
windowed enclosure (if applicable) to earth ground using 3/8" wide ground straps or
equivalent. EMC compliance testing has been successfully completed using these straps
and ungrounded tubing. However, if the flow tubing and electrical conduits are reliably
grounded by other means, these straps may not be necessary. These straps may also be
required to supply a reliable or redundant ground path for operation in hazardous
locations. Consult your plant’s safety engineer.
