31
7.2
Controlling an Ex nA solenoid valve
The BA377NE Timer is required to open an Ex n
solenoid valve for 5 minutes when an external
contact is closed.
55 minutes after the valve is
closed it is to be opened again for another 5 minute
period. This process is to be repeated 10 times after
which the Timer is to automatically reset so that is
ready to start the next 10 cycles when the external
contact is closed.
In this example illustrated in Fig 15, control output 2
has been wired to the timer reset terminals and
configured with a five seconds control output delay
after the solenoid valve has closed for the tenth
time.
Therefore five seconds after the tenth cycle
has been completed the system automatically resets
and is ready for the next timing cycle to be initiated.
The lower display is required to show timer status at
the start of each period.
After a power interuption the timer is required to
resume operation from the point at which it stopped
when the start button is operated.
Fig 15 Control of Ex nA solenoid valve in a
hazardous area.
The required instrument configuration for this
example are shown below.
Function
Display
Setting
Access code
CodE
0000
Function
FunCtion
ELAP5E
Input
inP
.
type
ContACt
debounce
dEbounCE
dEFAuLt
Display 2
di5P-2
5td
Start stop
5tAr5toP
ControL 2
Units
unit5
12
:
00
Set time
5Et t
00
:
05
Timer repeat cycle
CYCLE5
Cycle function enable
EnbL
on
Cycle count
cycl cnt
10
Reset delay
r5t dela
00
:
55
Access set time from
AC5Et - t
oFF
display mode.
Direction of count
uP or dn
uP
Power failure
p-fail
pau5e
Local total reset
rE5Et
.
EnbL
on
Local grand total reset
CLr Gtot
oFF
Enable control output 1
EnbL
on
Control output 1 on at
oP1 on
run
Control output 1 off at
oP1 oFF
n run
Control output 1 delay
oP1 dELA
00000
Enable control output 2
EnbL
on
Control output 2 on at
oP2 on
done
Control output 2 off at
oP2 oFF
re5et
Control output 2 delay
oP2 dELA
00005
In this example local total reset
rE5Et . EnbL
is
on
.
This enables the Timer to be reset when power is
first connected by operating the
*
and
&
down
button simultaneously for more than 3 seconds.
Summary of Contents for BA377NE
Page 1: ...Issue 6 3rd July 2018 BA377NE Rugged one input Ex nA and Ex tc Timer or Clock Issue 6...
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