Metric unit prefixes are associated with
powers ten.
Main Breaker
Main Lug Only designation given indicate that main breaker main
switch not included.21
Main Breaker The circuit breaker upstream from load center,
panelboard, switchboard, switchgear other equipment that
supplies the full current for that equipment.
Metric Unit Prefix Examples
. Circular mills are used
to designate the cross-sectional area round conductor. MCM 1000 circular mils (also shown as
1 kcmil).
One mill equal 1/1000 inch.The circular mill area a
solid, round conductor calculated squaring the conductor’s
diameter (in mills).
Main Lugs
MCM Abbreviation for thousand circular mils. For example, the metric unit prefix
kilo can added meter form unit length (kilometer)
equal 1000 meters.
Metric Unit Prefix prefix added unit measure increase decrease the
size that unit measure
