30
Operations- Long Time Fault Protection
Adjustable Continuous Amps and Adjustable Long Time Delay
Adjustable Continuous Amps
The Continuous ampere adjustment sets the current level at
which the breaker will continuously operate without initiating
a tripping sequence. On Siemens Electronic Trip Units, the
continuous operating current may be set to 50, 60, 65, 70,
75, 80, 85, 90, 95, and 100% of the rating plug value I
r
.
Continuous Operating Current
Adjustable Long Time Delay
The Long Time Pickup is nominally set at 115 percent of the
continuous amps setting. The Long Time Delay adjustment is
used to set the tripping delay of the SB breaker based on the
magnitude of the overcurrent condition. On Siemens Elec-
tronic Trip Units, the long time delay, which is an inverse 1
2
t
ramp function, may be set to a calibrated value of 2.5, 4, 5.5,
8, 10, 14, 17, 21, 25, or 30 seconds at a current equal to 6
times I
r
.
Long Time Delay
Courtesy of NationalSwitchgear.com
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