Pressure transducer grounding

[ptonsparky]

Looking at a 4-20 pressure transducer in a freq drive cabinet. Metallic transducer .Someone used a hoseclamp to attach a cu wire to it for some reason. It goes to an EG terminal of the enclosure.

Can someone enlighten me?

 

[ptonsparky]

Kind of what I thought, too.

It isn't possible.

 

[Dsg319]

I have seen some instrument techs on PT cut the grounding wire off of the seal tight (bonding jumper that is spec from gas company to wrap the sealtight with ) after the transition from RMC. But there is still the EGC inside the raceway that connects to the internal of the PT.

 

[4-20mA]

Might have been trying to eliminate some noise or interference like on some flowmeters. Possibly? Some of the bonding is overkill I think sometimes.

 

[ptonsparky]

Might have been trying to eliminate some noise or interference like on some flowmeters. Possibly? Some of the bonding is overkill I think sometimes.

I'd never seen someone do it before. Really crude. They even used a scrap piece of WHITE.

 

[rlundsrud]

A current loop is virtually immune to noise so I doubt that was the reason. I don't think the installer was making rational decisions given the methods used.

 

[4-20mA]

Yea, I dont agree with the method, but lots of pressure transmitters have a place for a bonding jumper to land on a screw on the outside of a transmitter. So noise isn't the most prevalent, but they want them bonded for some reason, it seems.

All 3 of these types do, right there on the right-hand side of the transmitter head.

Hell, around here, I'll try anything to keep a good steady zero or reading in general. Including bonding!

 

[petersonra]

For some reason the external earthing terminal is an IEC requirement.

 

[ptonsparky]

The one I saw is 1" + diameter, 4-20 ma, no external grounding means. Generally LLS. IMO.