http://www.nerc.com/files/BAL-005-0.pdf http://www.nerc.com/files/BAL-005-1.pdf
It would appear these documents are just talking about annual calibration requirements of the *transducer* (the control room test equipment used to measure line frequency) and do not imply a specification of line frequency itself. Does anyone know which NERC document specifies power line phase or frequency? (and note that a frequency measurement implies an averaging time). See http://leapsecond.com/pages/mains/ for the ADEV of power line frequency. It's ~2e-5 at one day. So does NERC owe me a million bucks or not? /tvb ----- Original Message ----- From: "Bill Hawkins" <[EMAIL PROTECTED]> To: "'Discussion of precise time and frequency measurement'" <time-nuts@febo.com> Sent: Friday, November 21, 2008 12:16 PM Subject: Re: [time-nuts] Do any regulations or laws require time tobeaccurate within 'x' seconds? > That's an interesting reference. Google finds it. > > Assuming that the digital frequency transducer measures the 60 Hz line > frequency, the required accuracy is somewhat less than 2 parts in 10E-5. > > Analog transducers, like Watts, Volts, and VARs, require 0.25% of scale > accuracy. Calibration is annual. > > This is nothing like the 10E-15 sought by time nuts. > > Bill Hawkins > > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of Mike Clapp > Sent: Friday, November 21, 2008 1:04 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Do any regulations or laws require time to > beaccurate within 'x' seconds? > > The North American Electric Reliability Corporation (NERC) under federal > law can fine of up to $1 million a day. > > Standard BAL-005-0 - Automatic Generation Control Requirement 17. Each > Balancing Authority shall at least annually check and calibrate its time > error and frequency devices against a common reference. The Balancing > Authority shall adhere to the minimum values for measuring devices as > listed below: > > Device Accuracy > > Digital frequency transducer ? 0.001 Hz _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
