13
Safe Ar
ea
See Note 9
Note 1
Apparatus which is unspecified except that it must not be supplied fr
om nor contain in normal
or abnormal conditions a sour
ce of potential with r
espect to earth in excess of 250 volts r
.m.s
or 250 volts d.c.
Note 2a
The capacitance and either the inductance or the inductance to r
esistance (L/R) ratio of the
cable connected between the + and
–
terminals of the power supply T
ype 4234500/501 and
terminals 1 and 4 of a kathar
ometer T
ype 0065XX must not exceed the following values:
Hazar
dous Ar
ea
See Notes 2 & 3
2
4
1
5
3
6
2
4
1
5
3
6
2
4
1
5
3
6
TB5
18
17
TB6
19
20
POWER SUPPL
Y
TYPE 4234 500/501
CER
TIFIED [EEx ia] IIC
(–
20
C
Ta
+55
C)
CER
TIFICA
TE No
BAS 01 A
TEX 7041
-
+
2
1
3
2
1
3
RS1
RS2
B1
B2
B3
6553 Display/Contr
ol Unit
–
+
Indicator
4689
I1
–
+
Indicator
4689
I2
4
–
1+
9
10
3
–
2+
KA
THAROMETER
TYPE 0065XXX
CER
TIFIED EEx ia IIC T4
Tamb=
–
20
C to +55
C
CER
TIFICA
TE No
BAS 01 A
TEX 1042
3
–
2+
10
4
–
1+
6
–
9
KA
THAROMETER
TYPE 0065XXX
CER
TIFIED EEx ia IIC T4
Tamb=
–
20
C to +55
C
CER
TIFICA
TE No
BAS 01 A
TEX 1042
Junction boxes (if r
equir
ed) see note 6.
Location: Hazar
dous Ar
ea or Safe Ar
ea
See Note 1
See Note 1
Junction boxes (if r
equir
ed) see note 6.
Location: Hazar
dous or Safe Ar
ea
RV
1
RV
2
Display/Contr
ol Unit
Model 6553
CER
TIFIED [EEx ia] IIC
T
amb=–20
C to +40
C
CER
T No BAS 01 A
TEX 7043
Gr
oup
Capacitance
in
F
Inductance
in mH
L/R ratio
in
H/Ohm
IIC
IIB
IIA
7.5
99
999
0.02
0.06
0.16
20
60
160
or
Gr
oup
Capacitance
in
F
Inductance
in mH
L/R ratio
in
H/Ohm
IIC
IIB
IIA
38
999
999
0.40
1.20
3.20
75
225
600
or
Gr
oup
Capacitance
in
F
Inductance
in mH
L/R ratio
in
H/Ohm
IIC
IIB
IIA
38
999
999
0.20
0.60
1.60
40
120
320
or
Note 2b
The capacitance and either the inductance or the inductance to r
esistance (L/R) ratio of the cables
connected between (a) terminals 17 & 18 of the display/contr
ol unit T
ype 6653 and terminals 9 & 10
of a kathar
ometer T
ype 0065XX, (b) terminals 19 & 20 of the display/contr
ol unit and terminals 9 & 10
of a kathar
ometer T
ype 0065XX, (c) terminal 4 & 5 of barrier B1 of display/contr
ol unit T
ype 6653 and
terminals 2 & 3 of a kathar
ometer T
ype 0065XX, must not exceed the following values:
Note 2c
The capacitance and either the inductance or the inductance to r
esistance (L/R) ratio of the cables
connected between 4 & 5 of barrier B2 plus terminal 4 of barrier B3 of display/contr
ol unit T
ype 6653
and terminals 2, 3 & 6 of a kathar
ometer T
ype 0065XX, must not exceed the following values:
See Notes 2 & 3
Cir
cuit A
Cir
cuit B (see Note 8)
Note 3
The cable may be separate cables or may be installed as separate cir
cuits within a type
‘A
’ or a type
‘B
’
multicor
e cable as defined in EN50039(1980) subject to the following:
a.
Each cir
cuit shall be individually scr
eened within a type
‘A
’ multicor
e cable.
b.
The peak voltage of any other cir
cuit within a type
‘B
’ multicor
e cable must not exceed 60 volts.
Note 4
The installation must comply with national r
equir
ements (e.g. in the UK EN60079-14:1997).
Note 5
The system must be marked with a durable label. The label should appear on or adjacent to the principal
item of electrical apparatus in the system or at the interface between the intrinsically safe and non-
intrinsically safe cir
cuits.
This marking shall include the wor
d SYST or SYSTEM, e.g.
‘BAS SYSTEM No Ex 01E2044
’ or
‘BAS No Ex 01E2044 SYST
’
Note 6
A
junction box, if used, must satisfy the r
equir
ements of Clauses 6.1 and 6.3.1 of EN50020:1994.
Note 7
Cir
cuit A or Cir
cuit B may be omitted.
Note 8
Cir
cuit B may be identical to Cir
cuit A.
Note 9
This item may or may not be fitted.
POWER SUPPL
Y
TYPE 4234 500/501
CER
TIFIED [EEx ia] IIC
(–
20
C
Ta
+55
C)
CER
TIFICA
TE No
BAS 01 A
TEX 7041
-
+
See Note 10
Note
10
Zenner barriers (B1
, B2 & B3) either MTL 7055ac BAS 99 A
TEX 7285 or MTL 7755ac BAS 01 A
TEX 7217
(MTL 7055ac barriers shown on diagram).
5.1
Electrical Interconnections – Fig. 5.1
Fig. 5.1 System Diagram
5
ELECTRICAL INSTALLATION
