Belden Hirschmann GREYHOUND GMM20, User Manual

Page: 12 / 96

12
Installation GREYHOUND Switch
Release 07 10/2020
Control Drawing for GRS 1042/1142 devices for use in Hazardous
Locations according to ANSI/ISA12.12.01-2015 Class I, Division 2,
Groups A, B, C, D
Rev.: 0 Document No.: 000205339DNR Page 2/2
Capacitance and inductance of the fi eld wiring from the non-incendive circuit to the asso-
ciated apparatus shall be calculated and must be included in the system calculations as
shown in Table 1 .
Cable capacitance ( C
cable
) plus non-incendive equipment capacitance ( C
i
) must be less than
the marked capacitance ( C
a
(or C
o
)) shown on any associated apparatus used.
The same applies for inductance ( L
cable
, L
i
and L
a
or L
o
, respectively).
Where the cable capacitance and inductance per foot are not known, the following values
shall be used:
C
cable
= 60 pF/ft (196.85 pF/m)
L
cable
= 0.2 μH/ft (0.66 μH/m)
Table 1:
Non-incendive
Equipment
Associated
Apparatus
V
max
(or U
i
) ≥ V
oc
or V
t
(or U
o
)
I
max
(or I
i
) ≥ I
sc
or I
t
(or I
o
)
P
max
(or P
i
) ≥ P
o
C
i
+ C
cable
≤ C
a
(or C
o
)
L
i
+ L
cable
≤ L
a
(or L
o
)
Suitability for installation in particular applications is at the discretion of the Authority Having
Jurisdiction (AHJ).