Wiring; Wiring Precautions - YOKOGAWA AXG1A Installation Manual

4.

Wiring

WARNING
The wiring of the magnetic flowmeter must be
performed by expert engineer or skilled personnel.
No operator shall be permitted to perform procedures
relating to wiring.
WARNING
For explosion protection type products, please be sure
to read the user's manual of the applicable explosion
protection type as listed in Table 1.1 before wiring.
CAUTION
Once all wiring is completed, check the connections
before applying power to the product. Improper
arrangements or wiring may cause a unit malfunction or
damage.
4.1

Wiring Precautions

Be sure to observe the following precautions when wiring:
CAUTION
• In order to maintain performance, wiring according
to regulations is necessary.
• When opening the cover, wait for more than 20
minutes after turning off the power.
• In cases where the ambient temperature exceeds
50°C, use external heat resistant wiring with a
maximum allowable temperature of 70°C or above.
• Do not connect cables outdoors in wet weather in
order to prevent damage from condensation and to
protect the insulation, e.g. inside the terminal box of
the flowmeter.
• Before turning the power on, tighten the terminal
box cover securely.
• For the remote type, do not splice the cable
between the transmitter and the sensor terminal
when it is too short. Replace it with a complete
cable of the appropriate length.
• For the remote type, ground the remote sensor and
the transmitter separately.
<4. Wiring>
CAUTION
• Terminate all the cable finish with crimp terminal of
a round or rod shape (depending on the shape of
the terminal block), and connect them reliably.
• Always route the power and output signal cables
in separate steel conduit tubes, except when the
power supply voltage is 24 V and four-core cables
are used for wiring. For the remote type, route the
excitation cable and the signal cable in separate
steel conduit tubes. Keep conduits or flexible tubes
watertight using sealing tape.
CAUTION
• If there is any unused cable entry, use the blanking
plug to cover which comes with this product or
which is supplied by YOKOGAWA. The blanking
plug should be fastened into the unused cable
entry without any mistake. If not, stated enclosure
protection is not applicable. One or two blanking
plug is provided depending on the specifications (24
V for power supply voltage or I/O selection).
• The signal cables must be routed in separate steel
conduit tubes 16 (JIS C 8305) or flexible conduit
tubes 15 (JIS C 8309).
• When waterproof glands or union equipped
waterproof glands are used, avoid tightening the
glands with an excessive torque.
• For the instruction of removing/installing the housing
covers and handling the locking screws, read
Section 4.4 and Section 4.5.
• Explosion protected types must be wired in
accordance with specific requirement (and, in
certain countries, legal regulations) in order to
preserve the effectiveness of their explosion
protected features.
IMPORTANT
For the remote type, prepare the excitation cable
(supplied by customer) and the signal cable of almost
the same length. It is recommended to lay them
together closely.
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IM 01E24A01-01EN