Description
The Model 272 3-Phase Current
Unbalance Detector monitors
3-phase lines to detect an
unbalanced current. It can
also monitor three separate
single phase lines for equal
current levels. The
percentage of unbalance is
adjusted from 2% to 25% by
adjusting a front panel
control. An unbalance greater
than this setting energizes
the relay. An adjustable trip
delay of 0.5 to 10 seconds is
also provided. For optimum
performance, operating
currents should be kept in
the 1 to 5 amps range.
However, zero current on each
phase is considered to be a
balanced condition.
Continuous currents, up to 10
amps per phase, will not
damage the unit, nor will
current surges up to 40 amps
for 2 seconds. The contacts
are automatically reset when
the unbalanced condition is
corrected.