YOKOGAWA EXA DO402G, User Manual

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<3. Installation and Wiring>
3-10
IM 12J05D02-01E
Location of grounding terminal
F0308.ai
(M4 Screw)
Figure 3.10 Grounding the housing
3.3.5 Switching on the instrument
After all connections are made and checked, the power can be switched on from the power
supply.
Make sure the LCD display comes on. All segments will illuminate, then the instrument will
momentarily display its unique serial number. After a brief interval, the display will change to
the measured value. If errors are displayed or a valid measured value is not shown, consult the
troubleshooting section (Chapter 8) before calling Yokogawa.
3.4 Wiring the contact signals
WARNING
There are high-voltage sections on the EXA. Be sure to turn off the power before wiring.
3.4.1 General precautions
The contact output signals consist of voltage-free relay contacts for switching electrical
appliances (SPDT). They can also be used as digital outputs to signal processing equipment
(such as a controller or PLC). It is possible to use multi-core cables for the contact in and output
signals and shielded multi-core cable for the analog signals.
We recommend that the cables be terminated with pin terminals (see figure 3.6).
3.4.2 Contact outputs
The EXA unit’s four contact outputs can be wired to suit your own custom requirements (Figure
3.8).
In the Non-Alarm or Power Off states, contacts S1, S2 and S3 are OFF, Common (C) and
Normally Closed (NC) are in contact.
In the “Fail” or Power Off states, contact S4 is ON, Common (C) and Normally Closed (NC) are in
contact.
You can either use them to switch AC power, or switch a DC Voltage for digital interfacing.
9th Edition: Aug. 05, 2015-00