ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat
Recent Posts
Elk’s Lodge 11th hour ritual chime clock
by lemahj - 09/26/23 10:24 AM
Strange breaker tip problem
by gfretwell - 09/25/23 08:13 PM
An impossible Support Violation
by gfretwell - 09/12/23 04:29 PM
How are you Jersey folks about the windmills?
by gfretwell - 09/08/23 02:21 PM
Having trouble logging in?
by Admin - 09/01/23 10:26 AM
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
2 members (Scott35, gfretwell), 27 guests, and 14 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
#87839 04/22/04 11:51 AM
Joined: Mar 2003
Posts: 849
Y
Member
Per 695.4 A a fire pump motor may be connected directly to the fire pump controller, bypassing any disconnect sw.(straigt from utility transformer) as long as the controller is a service rated listed controller,
Per 695.4 B a disconnect well be PERMITTED ,
but not required.
If a disconnect was installed it would be required to comply with 695.4 B (1)
Any comments ?? Hooking direct saves installing a Large disconnect sw(locked rotor current)
Wire size 125% full load current(695.6 c)

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
 

#87840 04/24/04 08:18 AM
Joined: Apr 2004
Posts: 201
Member
You have it correct already.

A disconnecting means or overcurrent protection is not required for the fire pump controller with the SUSE label since it already has the disconnecting means and overcurrent protection.

If you put in the overcurrent protection, it would have to carry locked current indefinitely. That would permit the fire pump motor to run to failure. Your overcurrent protection is only for short circuits and ground faults.

The controller will protect the wiring and the disconnect switch by interrupting the feed to the motor after 20 seconds of locked rotor current. At that point, the motor is already fried. That is why the switch and wire is sized the same as any other motor but the overcurrent protection is required to carry locked rotor current forever. [Linked Image]


Charlie Eldridge, Indianapolis Utility Power Guy

Link Copied to Clipboard
Featured:

Tools for Electricians
Tools for Electricians
 

* * * * * * *
2023 National Electrical Code (NEC)
2023 NEC + Exam Prep Study Guides Now Available!
 
* * * * * * *

2020 Master Electrician Exam Preparation Combos
2020 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Member Spotlight
BEAMEUP
BEAMEUP
WA
Posts: 27
Joined: December 2004
Top Posters(30 Days)
lemahj 1
Popular Topics(Views)
311,122 Are you busy
237,512 Re: Forum
221,282 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.5