_________________________________________________________________________________
Vaisala _________________________________________________________________________ 63
APPENDIX 2: WIRING FOR
INTRINSICALLY SAFE OPERATION, FM
Use FM approved associated apparatus;
zener barriers or galvanic isolators with
entity concept parameters:
V
oc
< 28 V
I
sc
<100 mA
C
a
> C
i
+ Ccable
L
a
> L
i
+ Lcable
HMT360-series transmitters are approved
for use in Classes I, II ans III,
Division 1, groups A-G and
Division 2, Groups A-D, F and G.
Safety factors for HMT360-series transmitters
are:V
max
= 28 V, I
max
=100 mA,
C
i
= 1 nF, L
i
=0, P
i
=0.7 W.
NOTE:
1. Barrier installation must be
completed in accordance with
ANSI/ISA RP 12.6 and the National
Electrical Code.
2. Intrinsically safe barrier ground
must be less than 1 ohm.
3. Maximum safe area voltage is 250 V.
Material
Weight
Finish
Part list
General tolerance
places
placed
epted
dler
ator
ecked
Scale
Title
Status
Code
Rev
01-09-04 ARH
1:1
CONTROL DRAWNING
DRW211603 A
Load Ch1
Vmax=28VDC
Vmax=28VDC
Load Ch2
Vaisala
Oyj
Vanha Nurmijärventie 21
Vantaa
Finland
HAZARDOUS AREA
SAFE AREA
ch1
ch2
