Honeywell Fema DCM-203-574 Series Assembly And Operating Instructions Manual page 71

7. Pressure Switches in In-
trinsically Safe Circuits
(Ex-i)
according to chapter 5.7 of EN 60079-11:2012,
"Simple electrical apparatus". Wiring
monitored applications.
Fig. 19. Connection layouts
The pressure switches correspond in all
technical data to the types DCM, DNS,
VCM, VNM, VNS, and DDCM. In addition,
a resistor-combination is provided in the
switching device, which – in combination
with a suitable (ATEX-certified) switching
amplifier – monitors the wires between the
switching amplifier and pressure switch for
open-circuit and short-circuiting. In the
case of open-circuit or short-circuiting, the
system switches off.
MU2B-0238GE51 R0616D
7. Pressure Switches in Intrinsically Safe Circuits (Ex-i)
Generally speaking: May be used only with
a suitable, E.C.-tested switching amplifier.
The switching amplifier is separately
certified and must be installed outside of
the Ex-zone. Pressure switches with
resistor-combination require a switching
amplifier suitable for monitoring open-
circuit and short-circuiting.
Wiring of switching amplifier only according
to its mounting and wiring instructions and
valid standards and guidelines for intrinsic
safe circuitry.
Electrical data of resistor-combination
1.5 k / 0.35 W, 10.0 k / 0.35 W
31