Onicon F-3100 Series Uživatelský manuál stáhnout pdf (Strana 30)

11451 Belcher Road South, Largo, FL 33773 • USA • Tel +1 (727) 447-6140 • Fax (727) 442-5699 • [email protected]

F-3100 Flow Meter Manual 06/14 - 0670-7 Page 30

3.3.3 Earth Connection

F-3100 Electromagnetic Flow Meters are designed to detect microvolt signal levels at the

electrodes located in the ow meter body. These signals are generated as conductive uids ow

through the magnetic eld generated by the meter. If enough random electrical noise is present at

the electrodes, it can interfere with the ow measurement. Care must be taken during installation

to minimize the effects of electrical noise on the ow meter.

The most effective way to minimize the effects of electrical noise is to make sure that the pipe,

uid, ow meter body and ow meter transmitter are all connected to the same earth ground.

This accomplishes two important goals. First, it ensures that the pipe, uid, ow meter body

and electronics are all at the same electrical potential, and second, it ensures that this electrical

potential is the same as earth ground.

In order to be certain that the meter is properly connected to earth, the ow meter body earth

connections (at the anges or on the neck of wafer meters) and the transmitter earth connection

should be run directly to a known earth connection. The length of this earth cable should be as

short as practically possible, preferably ≤25 feet in length. The table below lists earth connections

from best to worst.

IMPORTANT NOTE

Non-metallic pipes are more susceptible to electrical noise. Grounding rings installed upstream

and downstream of the ow meter body to reduce the electrical noise present in the pipe may be

required for proper operation.

CAUTION

Do not use bolts that hold pressure to make earth connections. Using ange bolts may result in poor

electrical connections due to the presence of paint and/or lubricants. Use the dedicated ange earth

connections or the dedicated earth connection on the neck of wafer style meters.

Earth Connections (stranded wire 14 - 18 AWG)

Best Earth grounding rod driven into the ground.

Earth wire connected directly to the building electrical service panel.

Worst Earth wire connection inside an electrical outlet near the meter.

1 2 ... 25 26 27 28 29 30 31 32 33 34 35 ... 40 41

Žádné komentáře

Onicon F-3100 Series Uživatelský manuál Strana 30