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operating frequency and the input terminal
numbers.   For reliable counting the input signal
must fall below the lower threshold and rise above
the upper threshold.

Switching

thresholds

Freq

max

Input

terminals

Switch

100

1000

100Hz

5 & 6

Proximity

detector

1.2mA

2.1mA

5 kHz

5 & 6

Open

collector

2k

10k

5kHz

5 & 6

Magnetic

pick-off

0mV

20mV

peak

5kHz

3 & 4

Voltage

pulse

1.0V

3.0V

5kHz

3 & 4

4.2.3 Switch contact input

Any mechanically activated switch contact located
in the hazardous area may be directly connected
to terminals 5 & 6 providing it can withstand a
500V rms insulation test to earth.  This includes
most magnetically activated reed relays used in
turbine flowmeters.  The BA338C contains filtering
to prevent contact bounce being counted, this
limits the maximum  operating frequency for a
switch contact to 100Hz.

4.2.4   2-wire proximity detector input

Any certified intrinsically safe 2-wire proximity
detector complying with NAMUR switching
thresholds may be used, providing the input safety
parameters are greater than the output safety
parameters of terminals 5 & 6.  The system
certificates list some of the acceptable devices.

When programmed to operate with a proximity
detector, the BA338C maximum input frequency is
5kHz.

4.2.5  Voltage pulse input

Voltage pulse sources should be connected to
terminals 3 and 4.   These terminals comply with
the requirements for simple apparatus and may be
directly connected to any certified intrinsically safe
voltage source within the hazardous area which
can withstand a 500V rms insulation test to earth
for one minute and has output parameters equal to
or less than:

Uo

=

28V dc

Io

=

100mA dc

Po

=

0.7W

This enables the BA338C to be connected directly
to most flowmeters incorporating a certified
intrinsically safe magnetic pick-off, or a certified
intrinsically  safe  amplifier  producing  a  high level

pulse output.    The BA338C has two programme
selectable voltage switching thresholds, ‘COIL’ for
magnetic pick-offs and ‘UOLtS’ for higher voltage
pulses.

Maximum voltage pulse counting frequency is
5kHz.

Fig 3 Pulse source in safe area

4.2.6  Remote reset

The BA338C total display is reset to zero  when
terminals 7 & 8 are connected together for more
than one second. Permanent interconnection
inhibits totalisation.   Remote resetting may be
accomplished by any mechanically operated
switch located in the hazardous area providing it
can withstand a 500V rms insulation test to earth.
No Zener barrier is required.

The BA338C may be reset to zero from the safe
area.   Any switch may be used but a  Zener
barrier is required to transfer the contact closure
into the hazardous area.  Any one of the diode
return barriers specified on the system certificate
can be used for this application, it may be
combined with the supply barrier so that only one
package is required.   Fig 2 illustrates how the
BA338C may be reset from both the safe and the
hazardous area.

Note:

  The BA338C can be programmed to reset

the total display to zero when the Up and Down
push-buttons are operated simultaneously for more
than two seconds – see 6.12.

Содержание BA338C

Страница 1: ...ry 2011 Certification information label Rate display Annunciators for optional alarms Rotating flow indicator Total display BA338C Intrinsically safe Externally powered pulse input panel mounting rate...

Страница 2: ...te interval 6 5 Type of input 6 6 Position of the decimal points 6 7 Lower display 6 8 Rate scale factor 6 9 Timebase 6 10 Rate filter 6 11 Total scale factor 6 12 Clip off 6 13 Local reset 6 14 Reset...

Страница 3: ...ost any pulse output flowmeter The total display may be reset to zero by a remote switch contact or from the front panel push buttons Optional accessories enable the flow rate to be transmitted to oth...

Страница 4: ...fied Body Intertek Testing Services ITS confirming compliance with the European ATEX Directive 94 9 EC for Group II Category 1 gas atmospheres EEx ia IIC T5 The instrument bears the Community Mark and...

Страница 5: ...lvanic isolator connected to terminals 3 and 4 The two system certificates specify maximum permitted cable parameters when 28V 300 devices are used 3 3 2 Contact 2 wire proximity detector or open coll...

Страница 6: ...nfirming that it complies with the requirements for Group II Category 1 G EEx ia IIC T5 Tamb 40 to 60o C specified in the ATEX Directive When connected to a suitable system the BA338C may be installed...

Страница 7: ...uit that is used for all BA338C installations protected by Zener barriers For simplicity connections for the optional pulse output 4 20mA output and backlight are included in the appendix to this manu...

Страница 8: ...tified intrinsically safe voltage source within the hazardous area which can withstand a 500V rms insulation test to earth for one minute and has output parameters equal to or less than Uo 28V dc Io 1...

Страница 9: ...is used to transfer the signal to the rate totaliser in the hazardous area Fig 5 Pulse source in safe area 4 3 1 Power supply Any certified galvanic isolator may be used to power the BA338C providing...

Страница 10: ...ces should be connected to terminals 3 and 4 These terminals comply with the requirements for simple apparatus They may be directly connected to any certified intrinsically safe voltage source within...

Страница 11: ...ent secured with four panel mounting clips The BA338C liquid crystal display has maximum contrast when viewed from directly ahead and slightly below the centre line of the instrument For reflective di...

Страница 12: ...ith the requirements of the European EMC Directive 2004 108 EEC For specified immunity all wiring should be in screened twisted pairs To prevent circulating currents cable screens should only be earth...

Страница 13: ...decimal points Moving the position of a decimal point in a scale factor will therefore affect the instrument calibration The BA338C updates its total flow calculation twice per second If the instrumen...

Страница 14: ...14...

Страница 15: ...AY 2 Lower display Turns the loweer display which normally shows rate on or off See section 6 7 Display Description of function SCALE r Rate Scale Factor Defines the arithmetic relationship between th...

Страница 16: ...sing Up or Down will scroll through the five options UOLts Voltage pulse input Threshold 1V and 3V 5kHz max Input terminals 3 and 4 COIL Low voltage pulse Threshold 20mV peak 5kHz max Input terminals...

Страница 17: ...on the decimal point in the rate scale factor move the flashing digit to the left hand side of the required decimal point position and simultaneously press the Up and Down buttons When the required ra...

Страница 18: ...next digit To position the decimal point in the scaling factor move the flashing digit to the left hand side of the required decimal point position and simultaneously press the Up and Down buttons Wh...

Страница 19: ...6 15 Security code CodE The calibration and conditioning of the instrument may be protected by a four digit security code which must be entered before access to the programme menu is granted New inst...

Страница 20: ...nput Using the Up or Down button scroll through the main menu until InPut is displayed then press P to reveal the existing setting Select COIL the input for a magnetic pick off using the Up or Down bu...

Страница 21: ...c metre so the BA338C is required to display 1 cubic metre for every 1 050 x 1 000 pulses received SCALE t should therefore be set to 1 050 000 Select SCALE t from the main menu and press P which will...

Страница 22: ...trument to the CLr Gtot prompt in the main menu Step 12 Define the security code Defining a security code prevents unauthorised access to the programme functions Select COdE from the main menu and pre...

Страница 23: ...alarms 8 2 Fault finding after commissioning ENSURE PLANT SAFETY BEFORE STARTING MAINTENANCE Live maintenance is permitted on intrinsically safe equipment installed in a hazardous area but only certif...

Страница 24: ...status of both alarms If an alarm delay or silence time has been selected the annunciator will flash during the delay or silence period Programmable functions for each alarm include adjustable setpoin...

Страница 25: ...ay Description of function EnbL Alarm enable Enables or disables the alarm function without changing the alarm parameters See section 9 3 4 tYPE Type of alarm Defines whether the alarm operates on the...

Страница 26: ...or the alarm type has been changed Both alarms must therefore be enabled after calibration changes 9 3 5 Type of alarm tYPE Alarm 1 and Alarm 2 may both be rate or total alarms or one may be conditio...

Страница 27: ...resis select HStr from the alarm menu and press P which will reveal the existing figure Each digit can be adjusted using the Up and Down push buttons and the P button to move to the next digit When th...

Страница 28: ...l disable the security code allowing direct access to the setpoints in the display mode by pressing the P and Up buttons simultaneously New instruments with alarms are supplied with the security code...

Страница 29: ...ght powered by Zener barrier The display brilliance depends upon the current flowing through the backlight This is determined by the supply voltage and the end to end resistance of the Zener barrier o...

Страница 30: ...ce and inductance specified by the system certificate of the circuit connected to the BA338C Fig 16 shows how the pulse output circuit may be powered from the BA338C supply to drive a counter in the s...

Страница 31: ...the rate display by the d P function The value of the flashing digit may be changed by pressing the Up or Down buttons When this digit is set as required pressing P will transfer control to the next...

Страница 32: ...4 Fault finding during commissioning 8 1 after commissioning 8 2 FILtEr 6 10 Flow indicator 2 3 FM Approval Appendix 1 Galvanic isolators 4 3 Gas groups 3 5 Grand total 2 2 clear 6 14 Guarantee 8 5 HI...

Страница 33: ...d with the following gases Intrinsic Safety Division 1 or 2 Class I Group A B Group C Group D Zone 0 1 or 2 Class 1 Group IIC Group IIB Group IIA The FM entity parameters are similar to the ATEX param...

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