GE Industrial Solutions EntelliGuard TU Trip Units - Manual (Page 33)

DEH-4567B EntelliGuard TU Trip Units: UL/ANSI Models
Setting up the Trip Unit
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the ST Band setting. OFF is found between the minimum
and maximum delay band setting positions.
If ST is turned off (Disabled) you cannot also disable IOC. If
IOC is disabled, you cannot turn off ST.
NOTICE
When ZSI is ON this becomes the PROTECTIVE,
UNRESTRAINED SETTING, not the selective setting and
the ZSI setting becomes the SELECTIVE, RESTRAINED
SETTING. In other words, when there is no ZSI input to
the trip unit, these are the settings that are in effect.
What this shows:
The ST delay is set to Band 4.
SHORT TIME SLOPE
The Short Time element protects the
electrical system from higher level
overloads.
Short Time Slope modifies the shape
of the “delay band” for the ST element.
See DES-092 and DES-097 for trip
time curve information.
The Slope setpoint has three available values:
• OFF – constant-time delay band
• 1 – 3 – Increasing slope values, with 1 being the lowest,
3 the highest.
What this shows:
The ST Slope is set to OFF (Constant Time).
If an i 4 t (fuse) LT delay band is in use, the ST slope is fixed to
OFF.
Figure 3-1: Short Time Slope
INSTANTANEOUS PICKUP
Instantaneous Pickup defines the
threshold where the INST element
begins to “timeout” toward tripping,
as a multiple of the Rating Plug
current (In).
If a 1600A Rating plug is installed, and
INST Pickup is set to 10.0, INST will go
into pickup when the current exceeds
16000A.
Instantaneous is an optional element.
If INST/IOC is not installed in your trip
unit, this screen will not appear.
INST pickup range is from 2.0 to a maximum value that is
breaker dependent. See DES-094 for EntelliGuard G, DES-
099 for Power Break, and DES-100 for Power Break II.
EntelliGuard G circuit breakers offer an optional “High
Range IOC” that extends the IOC pickup as high as 30 x the
Rating Plug current (frame limited).
Certain trip unit options allow INST to be turned off. This is
accomplished by selecting OFF as the Pickup threshold.
OFF is found between the minimum and maximum pickup
location if it the option is installed.
What this shows:
The INST Pickup setpoint is highlighted and set to 10.0 x the
Rating Plug current.
Slope OFF
Slope = 3
Slope = 1