# grounding problem

K

#### kaustubh

we have sanmar make weigh-indicator card installed
at our weighbridges.

Card supply -230v ac
currently we are facing problem of sudden fluctuations in indication.

i checked card it is okay ; i checked loadcells they are also okay.

I Checked the voltage between earth and neutral

i found it 10v ;

i want to know that can this much voltage can cause fluctuations in reading

what is the ideal voltage that is permissive for
digital circuits between earth and neutral

thank you in advance for the reply

kaustubh

C

#### chris

1. Were they OK after original installation?
2. Have they been subject to wetness?
3. Are they suddenly all faulty (how many have you)?
4. There is no 'ideal' voltage between digital circuit 0v and neutral. It depends upon the design.
5. Are you using any new equipment nearby e.g. Arc welders etc?
Chris

C

#### CT

Load cells read uV from srtain gauge. I would recomend checking Shield between sensor and display. verify on ly grounded on one end. Have seen similar on psi (strain ) gauge sensors. Recommended voltage between earth and ground = 0

CT

O

#### Omer Haluk Yilmaz

Hi,

Perhaps you solved the problem. If so please ignore my comments.

1- 10 V is not normal
2- Any voltage comparable to your source voltage is serious bad actor
3- If youre mentioning 10V (I assume a.c.), youve got an undesirable loop somehow. it could very commonly be an arc welder or even a permanent installation.
4- Analyze your grounding system (TT, TN, TS, TNS, TNC, TNCS, IT)
5- Check all the connections to make a neat drawing .

Regards,

Omer H. Yilmaz