Siemens Energy & Automation, Inc.
Bellefontaine, OH 43311 U.S.A.
Installation Instructions
Hazardous voltage.
Will cause death or
severe injury.
Turn off and lock out all power
supplying this device before
removing cover(s) or device and
while cover(s) are removed.
Replace all covers and shields
before power supplying this device
is turned on.
Page
4 of 5
Instantaneous Pickup
All models have an Instantaneous Pickup adjust-
ment. This adjustment sets the Instantaneous
Pickup of the circuit breaker. The settings are mul-
tiples of the Continuous Current Setting (lr).
These devices have a fixed instantaneous override
of approximately 10.5 times the Maximum Continu-
ous Current rating (ln) of the circuit breaker. When
set to “MAX” the Instantaneous Pickup defaults to
the instantaneous override value. See Figure 6.
Ground Fault Pickup (lg) (Optional)
Circuit breakers with the letter “G” included in the
catalog number have intergral equipment ground
fault protection. These circuit breakers have an ad-
justment to set the Ground Fault Pickup current (lg)
as a percentage of the Maximum Continuous Cur-
rent rating (ln). The pickup has a built in time delay.
Three time delays are available of 0.1, 0.2, or 0.4
seconds. These are selected by using the appro-
priate area of the setting. Below 50% Maximum
Continuous Current rating (ln) the pickup delay has
an I
2
t slope. See Figure 8.
The ground fault option has two modes of opera-
tion. The mode is set by a switch on the side of the
trip unit with the settings identified as RESIDUAL
and GROUND RETURN. See Figure 4 for switch
location. These function as follows:
Short Time Pickup/Short Time Delay (Optional)
Circuit breakers with the letters “NT” in the catalog
number have an adjustment to set both the Short
Time Pickup and the Short Time Delay. This single
knob sets both pickup and delay at the same time.
Four delays are available. These are fixed delays of
0.05, 0.1, or 0.2 seconds or an I
2
t delay slope at 0.2
seconds at 6 times the Continuous Current Setting
(lr). The delay is selected by using the appropriate
area of the setting knob. The pickup settings are
multiples of the Continuous Current Setting (lr) of
the circuit breaker. See Figure 7.
Fig. 7
Fig. 6
Fig. 8
