Grounding
Thread Content
Do field instruments have to be connected to a protective ground?
It’s not necessary, I’ve seen many instruments that don’t have a protective ground connection, but it’s better to have one for safety reasons.
Let’s see what instruments it is; thermometers, pressure gauges, etc. don’t require grounding, right? ! ! ! ! ! ! ! ! ! ! ! ! ! !
Instrument grounding comes in many forms, including shielding grounding, static electricity grounding, interference grounding, and lightning protection grounding...........
Unless you are using an electromagnetic flowmeter, there is no need for on-site grounding
Generally, field instruments, transmitters, etc. that use a DC24V power supply do not require protective grounding unless there are specific requirements.
The dashboard, instrument cabinets, instrument boxes, cabinets and operation stations for DCS/PLC/EDS, instrument power supply equipment, cable trays, conduit pipes, junction boxes as well as the shielding layer of armored cables, and the anti-static flooring in the control room, all require grounding~~
This post was last edited by feng*aosa on 2015-8-6 at 17:23. The internal circuit of the field instrument is insulated from its enclosure. When using shielded cables, it is possible to connect the shielding layer to the casing, or it is not necessary to do so. For grounding systems with side grounding installed at the instrument cluster, the grounds for signals and shielding are connected at that centralized point, and no connection is made between the conductor shielding layer and the instrument enclosure. If necessary, the case can be connected to the device’s ground connection (including through mounting brackets), and thus part of the same grounding system as pipe rack supports and similar elements ； For instruments that require on-site grounding, the signal, shielding, and enclosure shall be grounded at the same point on site (including treating the enclosure as a ground bus). For instruments with special grounding requirements, such as electromagnetic flowmeters, follow the instructions provided in the instrument’s technical manual.
Typical instrument enclosures can withstand a voltage of 2000V. If the voltage exceeds this value, congratulations – your instrument is now completely damaged. But I want to ask, where does this 2000V high voltage come from? :lol
It must be grounded to avoid any future problems; safety is of utmost importance.