Area Classification Drawings.....Why us?

[kenaslan]

:?Does anyone know why the electrical guys always do the area class drawings? Determining an area around a valve that has no electrical connection should be more of a process or pipers job. But yet electrical has done it since when dirt was young. Yea I know it is for determining conduit/fittings, just seems to me that process should do it.:happysad:

 

[Phil Corso]

Kenaslan...

In the golden days it became an "EE" task because they were thought to be more familar with locations of potential "sparking, arcing and overheated" electrics!

Early in my career a team of process, mechanical, and electrical engineers (note the hierchy) produced the draft layout. Of course, if one wants to get paid for his/her effort it aint a bad thing to do!

Regards, Phil Corso

 

[kingpb]

Area classification drawings should be done by a multi-disciplne collective group. For example, if you don't know how many air changes per hour exist, how can you detetrmine if it's Div 1 or Div 2?

 

[steve66]

I think we get stuck with it because its touched on in the electric code.

But I agree, it should be a group thing. But I normally find the rest of the group just won't provide any input.

On a more general note, it seems like the electrical people always have to be more a "jack of all trades" than other designers or construction people.

For example, we have to know something about the HVAC equipment in order to provide power to it.

However, sometimes the HVAC engineers don't even seem to realize their equipment needs electricity:blink:

As in: "When were you planning on telling me you added a 20 ton Roof Top Unit?" :?

 

[kenaslan]

Kenaslan...

Early in my career a team of process, mechanical, and electrical engineers (note the hierchy) produced the draft layout. Of course, if one wants to get paid for his/her effort it aint a bad thing to do!

Regards, Phil Corso

I have seen the hierchy for 35 years. We are always on the low end of the pole.

 

[weressl]

:?Does anyone know why the electrical guys always do the area class drawings? Determining an area around a valve that has no electrical connection should be more of a process or pipers job. But yet electrical has done it since when dirt was young. Yea I know it is for determining conduit/fittings, just seems to me that process should do it.:happysad:

Several reasons:

• Read 497 which defines area classification and you will find reference to the need for multidisciplinary effort.
• Area Classification requirement originates in NFPA 70 or NEC, so that squarely puts into the electrical field.
• OSHA is the one that requires documentation, not only primarily, but solely for the purpose to document that the installed electrical equipment complies with the determined Area Classification. In other words Area Classification documentation only exists because electrical electrical equipment and installation exist.
• I want to have a well reasoned explanation by that multidisciplinary group and come to a conscensus on why I have to install AND maintain the POA Classified Equipment.
• Since it puts a burden on me, if I have (primary) control over it I can make sure that no undue burden is imposed on me.