EMT Type Conduit for Med Voltage Feeders 1

[Josephlegge]

Is EMT type coduit UL approved for use as a raceway means for med voltage (13.8 kV) feeders? Joseph D. Legge, PE

 

[busbar]

Look like maybe it can. Sure wouldn’t want to ever rely on it for served-equipment grounding.

 

[dpc]

I don't know about UL, but NEC Article 358 does not appear to prohibit it. I don't think I've ever seen it used for 15 kv circuits however.

 

[busbar]

Make sure there are no local restrictions.

 

[busbar]

Also, be careful about calling EMT "conduit." It is a raceway, but it is "tubing."

 

[redtrumpet]

Based on my interpretation, the Canadian Electrical Code would prohibit using EMT for this application:

Section 36, High-Voltage Installations (>750 V)
36-100(2) Except as permitted in Paragraphs 1(b), 1(c), and 1(d), conductors used indoors or attached to buildings outdoors shall be:
(a) Installed in metal conduit; or
(b) Metal enclosed busways; or
(c) Cables having a continuous metal sheath, steel wire armour, or of the interlocking armour type; or
(d) Type TC tray cable installed in cable tray in accordance with Rule 12-2204.

As busbar says, EMT is tubing, not conduit.

 

[redtrumpet]

Just to back up the above, the Canadian Electrical Code definition of "conduit" is:

"Conduit means a raceway of circular cross-section, other than electrical metallic tubing and electrical nonmetallic tubing, into which it is intended that conductors be drawn."

 

[Josephlegge]

Thanks very much for all of the good responses.

I had a chance to review the NEC on this item last night. What I found was:
NEC (1996) 710-4 Did NOT allow EMT to be used for this application.
NEC (1999) 300-37 Allows EMT to be used for this application.

It appears from 1996 to the 1999 code the writers had a change in heart about this issue. Joseph D. Legge, PE