Emerson Micro Motion GDM - Page 31

Hazardous area mA/DO/TPS output wiring using safety barriersFigure 3-1:
Bus
Bar
Hazardous Area
Non-Hazardous Area
MTL7761AC
RS-485 A
RS-485 B
3
4
1
2
24 VDC
24 VDC
MTL7728P+
24 VDC
3
4
1
2
MTL7728P+
3
4
1
2
250 Ω
MTL7728P+
3
4
1
2
HART
Device
Signal
Device
See
note
mA1+
HART
RS-485
PWR
mA2/
TPS/DO
A
B
Note
The recommended resistance will vary depending on your Channel B output. For mA outputs, 250 Ω is the recommended
resistance. For TPS or Discrete outputs, 500–1000 Ω is the recommended resistance.
3.2.3 Wire Analog outputs using galvanic isolators
Micro Motion provides a galvanic isolator installation kit specific to wiring the Analog
version of the meter in a hazardous area. Contact your local sales representative or
Micro Motion Customer Support at flow.support@emerson.com for more information on
ordering an isolator kit for your meter.
Wiring
Installation Manual 27