Dwyer PMT - Manual (Page 17)

Particulate Monitoring Systems
Installation & Operating Manual
Document No. 210-1015-F Page 11 ©2007
6. Smart Transmitter Wiring
6.1 Grounding
Proper grounding is essential to ensure reliable operation and operator safety.
CONTROL UNIT GROUNDING
For One-Piece configurations:
• Connection to protective ground is made through the process mount.
Protective earth ground connection to external ground screw must be
installed when mounted to non-metallic or ungrounded process.
For Two-Piece configurations:
• Connection to protective ground is made through the process mount.
Protective earth ground connection to external ground screw must be
installed when mounted to non-metallic or ungrounded process.
• The remote electronics housing is connected to a separate earth ground
through an internal ground screw. Grounding to the neutral conductor of a
single phase circuit is not sufficient protection.
6.2 4-20mA Wiring
An appropriately licensed electrician must perform all electrical connections.
CONTROL UNIT WIRING
• All wiring must be rated 250V minimum. Analog 4-20mA wire should be
22 AWG stranded shielded twisted pair, Belden 88761 or equivalent.
• Analog 4-20mA cable shield should be terminated to earth ground in the
PLC/ DCS/ panel meter cabinet. The shielded wire should be terminated to
ground at one end only, never at both ends.
• The coaxial cable must be in conduit that is separate from all other circuits
for two piece configurations.
Conduit openings are provided in the bottom of the enclosure to route wiring into the enclosure.
Never drill new conduit openings in the side or top of the enclosure as a bad conduit seal may allow
water to enter the enclosure.