Connecting Conductive Parts To Earth; Amd Limit Switch; Amm Limit Switch; Th7 Transmitters - Techfluid SC250H Instruction Manual

24.3

Connecting conductive parts to earth

When the instrument is not grounded securely through the connection process, it should be
grounded through the housing screw, as shown in the figure.
24.4

AMD limit switch

When the equipment includes an AMD limit switch, it is certified as intrinsic safety with the
following parameters:
Specific parameters
24.5

AMM limit switch

When the equipment includes an AMM limit switch, can be certified as intrinsic safety. No
specific electric parameters are required for gas. In case of dust, the parameters are the
following:
24.6

TH7 transmitters

Transmitters TH7 can be supplied with certification to be installed in potentially explosive
atmospheres. They are intrinsic safety devices.
Differing from TH7 transmitters for safe zone, they do not have pulse output.
The electrical connection and the information respect the HART protocol is the same as in
the TH7 transmitter (see sections 13 to 19).
Marking
Pi : According to certificate
Earth
Ex ia IIC T4
Ui : 16 V
Ii : 25 mA
Pi : 64 mW
Ci : 50 nF
Li : 250 uH
Ii : 250 mA
46
Ex ia IIC T6
Ui : 16 V
Ii : 76 mA
Pi : 242 mW
Ci : 50 nF
Li : 250 uH