background image

e. Connect the field wiring to the terminals as

shown in Fig 6. 

f.

Replace the transmitter assembly and evenly
tighten the three 'B' screws.

g. Replace the enclosure cover and evenly

tighten the four 'A' screws.

Fig 6  Dimensions and terminal connections

5.3  EMC 

The BA374C complies with the requirements of the
European EMC Directive.  For specified immunity
all  wiring should be in screened twisted pairs.

6.  PROGRAMMING AND CALIBRATION

The BA374C is programmed and calibrated via
four push-buttons which are located behind the
enclosure cover.   All the functions are contained
in two easy to use menus, the Programme Menu
and the Trim Menu, which are shown diagramati-
cally in Figs 7A, 7B and 9. 

The Programme Menu contains all the transmitter
parameters and enables calibration to be
performed against the internal transmitter
references.

The Trim Menu enables the transmitter display and
the 4/20mA output current to be calibrated against
an external standard, such as a voltage source or
temperature calibrator. This is the preferred
method of calibration   A complete loop may be
calibrated using this menu to minimise errors
resulting from primary element and load
inaccuracies.
Each function in the programme menu is summa-
rised in section 6.1 and includes a cross reference
to more detailed information in the following
sections.  Although this simple menu driven
system enables most adjustments to be made
without repeated reference to this manual, we
recommend that the summary of the programme
menu, calibration procedure using the trim menu
and the calibration example in sections 6.1,  7.1
and 8 are read prior to changing function or
calibrating the transmitter.  Figs 7A, 7B and 9 show
the structure of the menus.

Details of the Trim Menu are contained in section 8
which also describes periodic calibration.

When the transmitter is fitted with alarms
additional functions are added to the programme
menu.  These are described in section 11 of this
manual.

Throughout this manual push-buttons are shown in
italics e.g.

 P 

or

 Up

 push-button, and legends

displayed by the indicator are shown within
inverted commas e.g. 'CAL' and ' ALr2'.

Access to the programme menu is obtained by
operating the 

P

 and 

E

 push-buttons

simultaneously.  If the transmitter is not protected
by a security code the first parameter 'InPut' will be
displayed.  If the transmitter is protected by a
security code,  'COdE' will be displayed first.
Pressing 

P

 again will  enable the security code to

be entered digit by digit using the 

Up

 and 

Down

buttons to change the flashing digit, and the 

P

   

push-button to move to the next digit.   If the
correct code is entered pressing 

E

 will cause the

first parameter 'InPut' to be displayed.   If an incor-
rect code is entered, or no button is pressed for ten
seconds, the transmitter will automatically return to
the operating mode. 

When the transmitter is in the programme menu
the 4/20mA output current will remain locked at the
value prior to starting programming, and it will
therefore not respond to any input change.
However, calibration of the 4/20mA output via the
'CAL' function, or re-calibration of the 4/20mA
reference via the 'Cond' function will change the
output current.

      9

Summary of Contents for BA374C

Page 1: ...BA374C Intrinsically safe field mounting indicating temperature transmitter Issue 5 3rd December 2003...

Page 2: ...ut current calibration 6 7 Security code 6 8 Calibrating the internal references 6 8 1 Conditioning internal references 6 8 2 Voltage input reference 6 8 3 3 wire RTD reference 6 8 4 4 wire RTD refere...

Page 3: ...Section 6 you will find information on setting up for Section 6 3 Thermocouple input Section 6 4 Resistance thermometer input Section 6 5 Voltage input A word of warning Section 6 8 explains how you...

Page 4: ...4...

Page 5: ...ing look up tables stored in permanent memory The resulting temperature is shown on the internal display and controls the 4 20mA output current The transmitter and the optional alarms are powered from...

Page 6: ...BA374C to be installed in all Zones and to be used with most common industrial gases at ambient temperatures between 40 60o C Note minimum operating temperature 20o C 3 4 Certification information la...

Page 7: ...Any certified diode return barrier may be used in the return wire For guidance System Certificate Ex96D2505 list some of these devices Fig 3 BA374C powered from a common supply When designing any loo...

Page 8: ...d such that the environmental conditions specified by the instru ment datasheet and the EC Type Examination Certificate are not exceeded Please consult BEKA associates if the instrument is to be insta...

Page 9: ...ogramme menu calibration procedure using the trim menu and the calibration example in sections 6 1 7 1 and 8 are read prior to changing function or calibrating the transmitter Figs 7A 7B and 9 show th...

Page 10: ...ctions in the programme menu is described in the following summary with a cross reference to more detailed information Figs 7A and 7B illustrates the location of each function within the menu Display...

Page 11: ...11...

Page 12: ...12...

Page 13: ...will reveal the current setting This setting may be changed by scrolling through the menu using the Up or Down buttons When the required input is displayed pressing P will reveal a sub menu enabling...

Page 14: ...esistance thermometer input from the InPut sub menu press P to reveal the tYPE sub menu Press P again to display the current type of resistance thermometer which may be changed by scrolling through th...

Page 15: ...transfer control to the next digit When the least significant digit has been adjusted press E to return to the InPut prompt from which the display prompt dISP can be selected by pressing the Up or Dow...

Page 16: ...Voltage input 3 wire RTD 4 wire RTD Current output The input voltage reference must be adjusted first irrespective of the transmitter application but it is only necessary to adjust the other three ref...

Page 17: ...ly 4mA The transmitter output current shown on the external current measuring instrument should be adjusted to 4 000 0 001mA using the transmitter Up and Down buttons When correct press the E push but...

Page 18: ...temperature of the primary element operate the Up or Down buttons until the transmitter display is correct Immediately the Up or Down button is operated the annunicator in the top left hand corner of...

Page 19: ...ple With tHC displayed press P to enter the thermocouple sub menu The first parameter tYPE will be displayed pressing P again will give access to the seven different types of thermocouple Select J usi...

Page 20: ...erature although this may be less accurate With the transmitter displaying the ZEro prompt and the correct input connected to the transmitter push P which will cause the transmitter to display the the...

Page 21: ...hazardous area but only certified test equipment should be used unless a gas clearance certificate is available If a BA374C fails after it has been functioning correctly the procedure shown in sectio...

Page 22: ...74C can be supplied with two solid state single pole alarm outputs Each output may be programmed as a high or low alarm with a normally open or a normally closed output Fig 10 illustrates the conditio...

Page 23: ...ary of programmable alarm functions Display Summary of function EnbL Alarm enable Enables or disables the alarm function without changing the alarm parameters See section 11 3 1 SP1 Alarm setpoint 1 A...

Page 24: ...24 Fig 13 Programme structure for optional alarms...

Page 25: ...rm output status select no nc from the alarm sub menu and press P reveal the current setting The function can be changed by pressing the Up or Down button followed by the E button to return the no nc...

Page 26: ...AcSP prompt in the Programme Menu Code 0000 will disable the security code allowing direct access to the setpoints by pressing the P and Up buttons simultaneously New instruments are supplied with thi...

Page 27: ...or galvanic isolator may be used providing the output parameters do not exceed Uo 30V dc Io 159mA Po 0 8W For guidance the system certificates list some of the devices which may be used Fig 15 Backli...

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