[BC] AC Voltage Drop

[Phil Alexander]

There is nothing I can recall in the NEC governing service drops,
but indirectly the voltage range of a drop should be satisfactory 
for operation of an electric motor consuming a reasonable ampacity
of which the transformer bank is capable. 

IOW any properly engineered drop plus transformer voltage variation
should satisfactorily operate a motor within the capacity of the 
bank. For example a transformer bank rated at 30 kW should operate
a 40 HP motor.

The governing document would be NEMA MG-1. You might try looking there,
but understand that utility compliance is not mandatory although it is
good engineering practice. The only other constraint might be the 
"brownout" voltage, but many utilities get around this restriction by
running an above nominal voltage most of the time so they are not
technically in "brownout" until they make their second system voltage
cutback.

Most utilities will be sensitive to a broadcast customer because they
are not interested in the bad publicity of investigative reporting, and
the better utilities do have a genuine interest in providing good
service to industrial/commercial customers.

Phil Alexander, CSRE, AMD

-----Original Message-----
>From: Danny Ray Boyer <drboyer at centralcom.com>
>
>To the NEC guru's on the list -
>
>Can anyone direct me to the paragraph(s) in the NEC handbook which 
>reflects what kind of voltage drop is permissible from an electrical 
>provider from no load to full load.