Greg, Conductors are sized at 125% of FLC (Full Load Current). However you'll need to know the wire run distance in order to compensate for voltage drop which may result in a conductor being larger than that required to carry 125% of FLC. Heres the code section;
2008 NEC 695.7 Voltage Drop. "The voltage at the controller line terminals shall not drop more than 15 percent below normal (controller-rated voltage) under motor starting conditions.The voltage at the motor terminals shall not drop more than 5 percent below the voltage rating of the motor when the motor is operating at 115 percent of the full-load current rating of the motor." Once you calculate 125% of FLC, Voltage Drop (NEC 695.7), Deratings (NEC 310.15), Determine the Conductor Size, Type and Temperature (NEC 310.16) and type of Raceway use the Annex C Conduit and Tubing Fill tables to determine Raceway Size. Hope that helps. John Drucker Jr CET Fire Protection Subcode Official Fire/Building/Electrical Inspector Borough of Red Bank, NJ -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Ron Greenman Sent: Wednesday, March 10, 2010 5:38 PM To: [email protected] Subject: Re: Fire Pumps and power Depends on the wire insulation type (75 degree C, 90 degree C, etc.), wire type (cu, al), voltage (208, 240, 480, etc.), and current (amperage of your particular 75 hp motor) as to what size wire you need. Then you can figure conduit size. That's in the NFPA 70 thing and it's a pretty easy thing to figure out if you know where to look. Kinda like 13. On Wed, Mar 10, 2010 at 1:50 PM, Greg McGahan <[email protected]> wrote: > Anybody know off the cuff if you can get the appropriate wire size for a 75 > hp pump in a 2-1/2" conduit? > > Greg McGahan > > Living Water Fire Protection > (850) 937.1850 | Fax (850) 937.1852 | Cell (850) 554.3231 > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > For Technical Assistance, send an email to: [email protected] > > To Unsubscribe, send an email > to:[email protected] > (Put the word unsubscribe in the subject field) > -- Ron Greenman Instructor Fire Protection Engineering Bates Technical College Tacoma, WA Member: SFPE, ASCET, NFPA, AFSA, NFSA AFAA, NIBS, WSAFM, WFC _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field) CONFIDENTIAL AND PROPRIETARY: This email message is intended only for the use of the individual or entity to which it is addressed and may contain information that is privileged and confidential, nor is it, unless specifically stated, intended to be relied upon by any person or persons other than the individual or entity named above and no warranties or representations are made or intended to persons or entities not named above. If the reader is not the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by telephone, return this message to the address above and delete all copies. Thank you. _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field)
