Yokogawa MH7 User Manual
User’s
Manual
Model MH7
Isolator
(Unified Signal Type)
IM 77J04H07-01E
Please read through this User’s Manual before use for correct handling.
Please keep this User’s Manual for future reference.
IM 77J04H07-01E
1st Edition Jul. 2003 (MC)
2nd Edition June 2004 (YK)
Network Solutions Business Divisiion
2-9-32, Naka-cho Musashino-shi, Tokyo 180-8750 Japan
Phone: +81-422-52-7179 Facsimile: +81-422-52-6793
1. CAUTIONARY NOTES FOR SAFE USE OF THE PRODUCT
This User’s Manual should be carefully read before installing and operating the product. The following symbol is used on the product and in
this manual to ensure safe use.
4.1 Wall Mounting
Remove the stoppers (top and bottom) from the product and pull out
the main unit from the socket. Fix the socket on the wall using two M4
screws. Next, insert the main unit into the socket and fasten the main
unit with the stoppers (top and bottom).
This symbol is displayed on the product when it is
necessary to refer to the User’s Manual for information on
personnel and instrument safety. This symbol is displayed
Main unit
in the User’s Manual to indicate precautions for avoiding
danger to the operator, such as an electric shock.
The following symbols are used only in this manual.
IMPORTANT
Indicates that operating the hardware or software in a
particular manner may cause damage or result in a system
failure.
<Mounting Dimensions>
Socket
2-ø4.5 or 2-M4
NOTE
Draws attention to essential information for understanding
the operations and/or functions of the product.
2.
CHECKING PRODUCT SPECIFICATIONS AND PACKAGED ITEMS
(1) Checking the Model and Product Specifications
Check that the model and specifications indicated on the nameplate
attached to the side face of the main unit are as ordered.
4.2 DIN Rail Mounting
Insert a DIN rail into the upper part of the DIN rail groove on the rear of
the socket, and then slide the slide lock at the lower part of the socket
upwards until the socket is fixed into position as shown below.
(2) Packaged Items
Check that the packing carton contains the following items:
● MH7: 1
● Receiving resistor (for currrent input): 1
● Spacer (used for DIN rail mounting): 1
● User’s Manual (this manual: IM 77J04H07-01E): 1 copy
40±0.2
DIN rail
3. GENERAL
This plug-in type isolator receives 4 to 20 mA DC current or 1 to 5 V DC
voltage signals to convert them into isolated 4 to 20 mA DC current or 1
to 5 V DC voltage signals.
Pitch: 55 or more
5 or more
(51)
Push
Mounting
screws
(85)
Fit into here
DIN rail
Spacer
Stopper
Socket
Unit: mm
Note:
(1) More than 5 mm interval is
required for side-by-side
close mounting.
(2) Use the supplied spacer for
DIN rail mounting to keep 5
mm interval.
(Rear of the socket)
4. MOUNTING METHOD
NOTE
Insert/pull out the main unit into/from the socket vertically
to the face of socket. Otherwise the terminals are bent and
it may cause a bad contact.
Slide lock
4.3 Using a Duct
When using a wiring duct, install the duct at leaset 20 mm away from
the top and bottom faces of the main unit.
5. INSTALLATION LOCATIONS
y
t
(
)
t
● Avoid the following environments for installation locations:
Areas with vibration, corrosive gases, dust, water, oil, solvents, direct sunlight, radiation, a strong electric field, and/or a strong
magnetic field
● If there is any risk of a surge being induced into the power line
and/or signal lines due to lightning or other factors, a dedicated
lightning arrester should be used as protection for both this unit
and a field-installed device.
6. EXTERNAL WIRING
WARNING
To avoid the risk of an electric shock, turn off the power
supply and use a tester or similar device to ensure that no
power is supplied to a cable to be connected, before carring
out wiring work.
Wiring should be connected to the terminals on the socket of the product. The terminals for external connections are of M3.5 screws. Use
crimp-on terminal lugs for connections to the terminals.
● Recommended cables: A nominal cross-sectional area of 0.5 mm
or thicker for signal cables, and that of 1.25 mm2 or thicker for
power cables.
Receiving resistor
for current inpu
Power Suppl
GND
6
L+
7
N–
8
Input
+
3
Ri
4
–
: 250 external receiving resistor
for current input
Output
+
1
–
2
RES-250
7. PART NAMES OF FRONT PANEL
The figure below shows the MH7 with its front panel (cover) being
open.
Zero-adjustment volume
Span-adjustment volume
Power indicator lamp
Lit during power on
8. MAINTENANCE
The product starts running immediately when the power is turned on;
however, it needs 10 to 15 minutes of warm-up before it meets the
2
specified performance.
8.1 Calibration Apparatus
● A DC voltage/current standard (Yokogawa 7651 or the equivalent)
● A digital multimater (Yokogawa 7561 or the equivalent)
● A precision resistor of 250 ± 0.01%, 1 W
8.2 Calibration Procedure
(1) Connect the instruments as shown below.
(2) Use the DC voltage/current standard and apply input signals
equivalent to 0, 25, 50, 75, and 100% of the input span to the
product. Check to see the corresponding output voltages are 0,
25, 50, 75, and 100% respectively and within the specified accuracy rating. “R” is used for current output.
● If the output signals are out of the accuracy rating range, adjust
the output signal level using the zero and span adjustment volumes on front face of the product.
IMPORTANT
●
The power line and input/output signal lines should be
installed away from noise-generating sources. Other
wise accuracy cannot be guaranteed.
●
The grounding resistance must be 100 Ω (JIS Class D
grounding). The length and thickness of the grounding
cable should be as short and thick as possible. Directly
connect the lead from the ground terminal (terminal no.
6) of the product to the ground. Do not carry out daisychained inter-ground terminal wiring.
●
Use of the product ignoring the specifications may
cause overheating or damage. Before turning on the
power, ensure the following:
(a) Power supply voltage and input signal value applied
to the product should meet the required
specifications.
(b) The external wiring to the terminals and wiring to
ground are as specifications.
●
Do not operate the product in the presence of
flammable or explosive gases or vapors. To do so is
highly dangerous.
●
The product is sensitive to static electricity; exercise
care in operating it. Before you operate the product,
touch a nearby metal part to discharge static electricity.
Receiving resistor
for current inpu
Power supply
GND
6
L
7
N
8
Input
3
DC voltge/
current
Ri
standard
4
Ri
: External receiving resistor for
current input
Output
1
Digital
Ro
multimater
2
Ro
: 250 precision resistor
for current output
2
IM 77J04H07-01E 2nd Edition June 01,2004-00
Loading...