Yokogawa EJA530E - Manual (Page 32)

<7. Operation>
7-4
IM 01C25F01-01E
7.5 Setting the Range Using the
Range-setting Switch
WARNING
The range setting switch must not be used in the
hazardous area.
When it is necessary to use the switch, operate it
in a non-hazardous location.
When pressure is applied to the transmitter, the low-
and high-limit values for the measurement range
(LRV and URV) can be changed (re-ranged) using
the range-setting switch (push-button) located on
the optional integral indicator plate and the external
zero adjustment screw. This procedure does
not require use of the communicator. However,
changes in the scale range and engineering unit
display settings for the integral indicator require use
of the communicator.
Follow the procedure below to change the LRV and
URV settings.
[Example]
Rerange LRV to 0 and URV to 3 MPa.
1) Connect the transmitter and apparatus as
shown in Figure 8.1 and warm it up for at least
ten minutes.
2) Press the range-setting push-button.
The integral indicator then displays “LRV.SET.”
3) Apply a pressure of 0 kPa (atmospheric
pressure) to the transmitter. (Note 1)
4) Turn the external zero-adjustment screw in the
desired direction. The integral indicator displays
the output signal in %. (Note 2)
5) Adjust the output signal to 0% (1 V DC) by
rotating the external zero-adjustment screw.
Doing so completes the LRV setting.
6) Press the range-setting push-button. The
integral indicator then displays “URV.SET.”
7) Apply a pressure of 3 MPa to the transmitter.
(Note 1)
8) Turn the external zero-adjustment screw in the
desired direction. The integral indicator displays
the output signal in %. (Note 2)
9) Adjust the output signal to 100% (5 V DC) by
rotating the external zero-adjustment screw.
Doing so completes the URV setting.
10) Press the range-setting push-button. The
transmitter then switches back to the normal
operation mode with the measurement range of
0 to 3 MPa.
Note 1: Wait until the pressure inside the pressure-detector
section has stabilized before proceeding to the next
step.
Note 2: If the pressure applied to the transmitter exceeds the
previous LRV (or URV), the integral indicator may
display error number “AL.30” (In this case, the output
signal percent and “AL.30” are displayed alternately
every two seconds). Although “AL.30” is displayed,
you may proceed to the next step. However, should
any other error number be displayed, take the
appropriate measure in reference to , “Errors and
Countermeasures” in each communication manual.
IMPORTANT
• Do not turn off the power to the transmitter
immediately after completion of the change
in the LRV and/or URV setting(s). Note
that powering off within thirty seconds after
setting will cause a return to the previous
settings.
• Changing LRV automatically changes URV
to the following value.
URV=previous URV+(new LRV–previous LRV)
• If the range-setting push-button and external
zero-adjustment screw are not touched
during a range-change operation, the
transmitter automatically switches back to
the normal operation mode.
F0705.ai
Integral indicator
Range-setting switch
(Push-button)
Note 1: Use a thin bar which has a
blunt tip, e.g., a hexagonal
wrench, to press the
range-setting push-button.
Note 2: The push-button is located
in either lower right or
lower left portion of the
LCD indicator.
Figure 7.5 Range-setting Switch