ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat
Recent Posts
100 Definitions: Accessible 2023
by gfretwell - 07/18/24 04:26 PM
240V only in a home and NEC?
by emolatur - 07/18/24 01:05 PM
2023 CEU Course
by gfretwell - 07/17/24 01:08 AM
Is this really a thing
by dsk - 07/16/24 01:23 PM
90.5(C) Explanatory Material 2023
by gfretwell - 07/16/24 12:14 PM
New in the Gallery:
This is a new one
This is a new one
by timmp, September 24
Few pics I found
Few pics I found
by timmp, August 15
Who's Online Now
0 members (), 496 guests, and 29 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
#79965 02/11/02 01:32 AM
Joined: Jan 2002
Posts: 36
N
Member
I'd appreciate some feed back on this.
Friend of mine owns a custom racemotor shop.He recently bought what I think he called a "shore-pac" unit. Basically a rolling unit with a 480v 3-phase motor ( 8 amps) which drives a large fan for ventilation, for use when welding certain metals. (some osha requirement). The unit would need to be rolled around the shop close to wherever the welding was done.The 480v service panel is located in his shop, but you must exit is shop and walk around the other side of the building for access.All he wanted was advice as to what to suggest to or expect from the E.C. he hired.
My suggestions off the top of my head was..
-3/4" emt (approx.75') w/3- #10's+ grounding conductor on a 15 amp breaker.

- a 30 amp fusible disconnect with integral twistlock plug where the plug can not be removed with out de-energizing the load side of the disconnect. ( I believe Hubbel makes these...."circuit-locks" ??)

-50' of 8-3 w/g cord with the proper Pin/Sleeve connectors ( not sold on this with 480, but I couldnt come up with a safer way considering the mobility need)

- strain reliefs on the cord at the disconnect location and "shore-pac", to hold the cord secure.

Now, what WAS installed a week later ( by a NATIONAL known electrical contractor) ..

- 75' of 1/2" emt with 3-# 12's ( no ground)
- a 480v twistlock plug ( not pin/sleeve) in a 5-square box with raised cover.

DONE!

Was I way of base with this? (overkill) ???

At the very LEAST a disconnect.
Sorry for being so long winded.

Regards,
NS4M

Stay up to Code with the Latest NEC:


>> 2023 NEC & Related Reference & Exam Prep
2023 NEC & Related Reference & Study Guides

Pass Your Exam the FIRST TIME with the Latest NEC & Exam Prep

>> 2020 NEC & Related Reference & Study Guides
 

#79966 02/11/02 08:41 AM
Joined: Mar 2001
Posts: 2,056
R
Member
A few thoughts--
Does the unit have a starter or combination starter on it? Although the plug may qualify as a disconnect for the motor, a switch would be nice. In an emergency, I would not want to unplug it under load.
The 3 #12s don't seem to be a problem, but at 480 volts, an EGC would certainly provide a much safer installation.
Also, depending on the size of the shop, more than one receptacle would be nice. This would minimize cord length, and the likelihood of it being damaged.

#79967 02/11/02 03:42 PM
Joined: Feb 2002
Posts: 4
B
Junior Member
It sounds like this is a 5 hp motor.If it is you have to size the conductor for about 9.5 or 10 amps.With motors you can use the amperage from table 310-16 A #12thhn is good for 30 amps.


Link Copied to Clipboard
Powered by UBB.threads™ PHP Forum Software 7.7.5