Yokogawa VJT6 User Manual

User’s
Manual

Model VJT6
Thermocouple Converter
(Isolated Single-output and
Isolated Dual-output Types)

IM 77J01T06-01E

Please read through this User’s Manual before use for correct handling.
Please keep this User’s Manual for future reference.

IM 77J01T06-01E

©Copyright July 2003

4th Edition Feb. 2007

Network Solutions Business Divisiion

2-9-32, Naka-cho Musashino-shi, Tokyo 180-8750 Japan
Phone: [phone] Facsimile: [phone]

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.

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 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.

NOTE

Draws attention to essential information for understanding
the operations and/or functions of the product.

4.1 Wall Mounting

Loosen the main unit-fixing screw of the product and pull out the main
unit from the socket. Fix the socket on the wall with screws. Next, in­sert the main unit into the socket and fasten the main unit with the main
unit-fixing screw.

Socket

Threaded hole for
fixing the main unit

Unit: mm

Output-1

Zero-adjustment volume

Span-adjustment volume

Output-2

Zero-adjustment volume

Span-adjustment volume

<Mounting Dimensions>

29.5 or more
22±0.2

59±0.3

Mounting

Main unit

Main
unit-fixing
screw

2-M4 or 2-ø4.5 or more

screws

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.

(2) Packaged Items

Check that the packing carton contains the following items:

● VJT6: 1

● Tag number label: 1 sheet

● RJC sensor (A1167HT): 1(*)

Not provided for the input signal code 7 (Type B).

● User’s Manual (this manual: IM 77J01T06-01E): 1 copy

3. GENERAL

This plug-in type thermocouple converter is connected to an IEC/JIS­standard thermocouple(TC) to convert temperature signals into isolated
DC current or DC voltage signals.

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.

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.

Fit into here

DIN rail

DIN rail

Push

(Rear of the socket)

DIN rail

Slide lock

4.3 Mounting Using a Multi-mounting Base

When using a multi-mounting base, see the User’s Manual for VJCE
(VJCE Mounting Base).

4.4 Using a Duct

When using a wiring duct, install the duct at leaset 30 mm away from
the top and bottom faces of the main unit.

5. INSTALLATION LOCATIONS

The RJC sensor for the product

(For the VJT6 with style of 3.00
or higher)

The RJC sensor for the VJT6 with
former style

“Not available for the VJT6 with
style of 3.00 or higher”

Part number: A1167HT Part number: E9786WA

● 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

●

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.

7. 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
specified performance.

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 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.

<Mounting position of RJC> <Wiring>

RJC sensor

(A1167HT)

3 2

1

56

4

Signal
line

Recommended crimp-on lug
size (Unit: mm)

5.5 or less

789

1011

ø3.2 to 3.5

RJC
sensor

Terminal
screw

3 2

56

1011

Power supply

1110 8

L+

Input signal

+

1

–

3

RJC

Output-2

+

2

–

5

Output-1

+

7

–

9

4

1

4

789

GND

N–

7.1 Calibration Apparatus

●

Calibrator (Yokogawa Meters & Instruments‘ CA71 or equivalent): 1

● Temperature sensor (
or equivalent

): 1

Yokogawa

Meters & Instruments‘

B9108WA

● Digital multimater (Yokogawa 7561 or equivalent): 1

● Precision resistor of 250  ± 0.01%, 1 W

7.2 Calibration Procedure

(1) Connect the instruments as shown below. First adjust the output-1

signal and then the output-2 signal.

2

(2) Use the calibrator 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.

Input

+

Calibrator

Temperature sensor (B9108WA)

1

3

–

3 2

1

56

4

789

1011

Power supply

1110 8

L N GND

Output-2



2

Digital

R

multimater



5

Output-1



7

Digital

R

multimater



9

R: 250  precision resistor
for current output

5.5 or more

IMPORTANT

●

Connect the RJC sensor at the correct position as shown
above. Otherwise temperatures cannot be measured
correctly.

●

Connect the RJC sensor so that it overlaps the input
signal line.

●

Handle the RJC sensor lead wire with care to prevent
disconnection.

●

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.

8) 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 toground

are as specifications.

8. RJC Sensor

NOTE

The product works normally when the RJC sensor
“A1167HT” (see the figures below) is connected to the
socket. If another RJC sensor is connected, it does not
work normally. Make sure that the correct RJC sensor is
connected referring to the figures below.

The style of VJT6 is indicated on the nameplate attached to the
side face of the main unit.

2

IM 77J01T06-01E 4th Edition Feb. 09,2007-00