User Manual

20 FLEX Ex I/O 24V DC 4 Non-Isolated Source Output Module
Publication
1797-5.6 - June 2011
The values of L
o
and C
o
listed in the table above are allowed if one of the
following conditions is met:
• The total L
i
of the external circuit (excluding the cable) is < 1% of the
L
o
value or
• The total C
i
of the external circuit (excluding the cable) is < 1% of the
C
o
value.
The values of L
o
and C
o
listed in the table above shall be reduced to 50%
when both of the following conditions are met:
• The total L
i
of the external circuit (excluding the cable) is ≥ 1% of the
L
o
value and
• The total C
i
of the external circuit (excluding the cable) is ≥ 1% of the
C
o
value.
Note:
The reduced capacitance of the external circuit (including cable) shall
not be greater than 1µF for IIB and IIA and 600nF for IIC.
UL, C-UL I/O Entity Parameters
If this product has the UL/C-UL mark, it has been designed, evaluated,
tested, and certified to meet the following standards:
• UL 91
3, 1988, Intrinsically Safe Apparatus and Associated Apparatus
for Use in Class I, II, and III Division 1, Hazardous (Classified)
Locations
Entity Parameters
Protection Group Allowed
Capacitance
Allowed
Inductance
1797-OB4D
U
o
= 27.4V
I
o
= 110 mA
Ex ia IIB 677 nF 8 mH
IIC 87 nF 2 mH
If concentrated capacitance
and/
or inductance are available,
use the following values.
Ex ia IIB 150 nF 5 mH
IIC 30 nF 2 mH