Wiring For Rs485; Shell Grounding And Elimination Of Interference; Requirement On Wiring - Bell VFM60 Series User Introduction Manual

3.2.4 Wiring for RS485

3.3 Shell grounding and elimination of interference

In VFM60 digital vortex flowmeter the power supply of signal processing circuit is transferred
from outside power supply by a isolation type DC-DC transmitter with advanced grounding technology.
The field frequency interference can be isolated well.
When using this product, the "V-" of power supplier should not be connected with the ground.
When this product is used in a environment with strong interference, the shell should be connect with
earth through cable , so the interference can be eliminated .

3.4 Requirement on wiring

1) Please conduct wiring when the power is on in a explosive environment.
2) Please open the rear cover first, then inert the cable into back zone of housing thourgh the
water-proof cable gland.
3) Conduct wiring according to 3.1 and 3.2.
4) If possible, please conduct the wiring according to picture 3.0 to avoid the water get into the housing
through the cable.
Date:24/04/2020
Picture 3.9: Wiring for RS485
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VFM-60
Vortex Flowmeter
Rev1.3
User's Manual