I.B. 17555C
Effective November 1999
Page 23
Fig. 3-3
Sample Electronic Trip Curves
Ground Fault Protection
The ground fault protection function can be a composite
of the ground: 1) inverse time overcurrent curve shape,
pickup, and time, 2) short delay pickup and time, 3)
instantaneous pickup. Its curve shape is independent of
the phase curve. There are two differences between Dig-
itrip 3000 phase and ground functions: 1) Inverse time
overcurrent time multiplier values for the ground function
of the thermal curves are for (1 x I
n
) while the phase is (3
x 2) The short delay settings are more sensitive and can
be set from (0.1 x I
n
) to (11 x I
n
). Movement of the pickup
portion of the curve in a horizontal direction and the time
portion of the curve in a vertical direction is similar to
phase inverse time over-current, short delay and instan-
taneous functions previously described. Therefore,
ground fault curve movement is not graphically illustrated.
Refer to Table 2.3 for the available ground fault settings.
When programming ground fault protection, keep in mind
that if “NONE” is selected, the ground fault protection is
disabled. Even if the ground fault protection is disabled, a
detectable ground current will still be displayed.
Characteristic Curve Reminders
As previously mentioned, combining protective capabili-
ties is a matter of coordination. The effects of one selec-
tion should always be evaluated against other selections
to determine if the overall desired result is obtained. For
this reason, keep in mind the following Digitrip 3000
selection possibilities and relay design features when
programming the unit to closely coordinate with system
protective needs:
1.
When “NONE” is selected as a setting, the associ-
ated tripping function is disabled.
2.
When “NONE” is selected for the Phase Instanta-
neous Setting, a Phase Discriminator option is
offered.
3.
The internal design of the Digitrip 3000 Protective
Relay is such that the Short Delay Time setting might
take precedence over the Inverse Time Overcurrent
Time. This is graphically illustrated in Figure 3-8.
Содержание Cutler-Hammer Digitrip 3000
Страница 18: ...I B 17555C Effective November 1999 Page 12 Fig 2 1 Typical Communications Wiring Diagram...
Страница 27: ...I B 17555C Effective November 1999 Page 21 Fig 3 1 Digitrip 3000 Typical Wiring Diagram...
Страница 36: ...I B 17555C Effective November 1999 Page 30 Fig 3 11 Local Programming Sequence Flow Chart...
Страница 37: ...I B 17555C Effective November 1999 Page 31...
Страница 48: ...I B 17555C Effective November 1999 Page 42 Fig 7 1 Inverse Time Overcurrent Phase I4T Curves SC 5390 92B...
Страница 49: ...I B 17555C Effective November 1999 Page 43 Fig 7 2 Inverse Time Overcurrent Phase I2T Curves SC 5391 92B...
Страница 50: ...I B 17555C Effective November 1999 Page 44 Fig 7 3 Inverse Time Overcurrent Phase IT Curves SC 5392 92B...
Страница 51: ...I B 17555C Effective November 1999 Page 45 Fig 7 4 Inverse Time Overcurrent Phase Flat Curves SC 5393 92B...
Страница 52: ...I B 17555C Effective November 1999 Page 46 Fig 7 5 Short Delay Phase Curves SC 5394 92B...
Страница 53: ...I B 17555C Effective November 1999 Page 47 Fig 7 6 Inverse Time Overcurrent Short Delay Curves SC 5395 92B...
Страница 54: ...I B 17555C Effective November 1999 Page 48 Fig 7 7 Instantaneous Curves SC 5396 92B...
Страница 55: ...I B 17555C Effective November 1999 Page 49 Fig 7 8 Inverse Time Overcurrent Ground I4T Curves SC 5399 92B...
Страница 56: ...I B 17555C Effective November 1999 Page 50 Fig 7 9 Inverse Time Overcurrent Ground I2T Curves SC 5400 92B...
Страница 57: ...I B 17555C Effective November 1999 Page 51 Fig 7 10 Inverse Time Overcurrent Ground IT Curves SC 5401 92B...
Страница 58: ...I B 17555C Effective November 1999 Page 52 Fig 7 11 Inverse Time Overcurrent Ground Flat Curves SC 5402 92B...
Страница 59: ...I B 17555C Effective November 1999 Page 53 Fig 7 12 Short Delay Ground Curves SC 5403 92B...
Страница 60: ...I B 17555C Effective November 1999 Page 54 Fig 7 13 ANSI Moderately Inverse Curves SC 6685 96...
Страница 61: ...I B 17555C Effective November 1999 Page 55 Fig 7 14 ANSI Very Inverse Curves SC 6686 96...
Страница 62: ...I B 17555C Effective November 1999 Page 56 Fig 7 15 ANSI Extremely Inverse Curves SC 6687 96...
Страница 63: ...I B 17555C Effective November 1999 Page 57 Fig 7 16 IEC A Moderately Inverse Curves SC 6688 96...
Страница 64: ...I B 17555C Effective November 1999 Page 58 Fig 7 17 IEC B Very Inverse Curves SC 6689 96...
Страница 65: ...I B 17555C Effective November 1999 Page 59 Fig 7 18 IEC C Extremely Inverse Curves SC 6690 96...
Страница 66: ...I B 17555C Effective November 1999 Page 60 Fig 7 19 IEC D Flat Curves SC 6691 96...
Страница 68: ...I B 17555C Effective November 1999 Page 62...
Страница 73: ...I B 17555C Effective November 1999 Page A5 Fig A 7 DT3001 Typical Wiring Diagram...
Страница 76: ...I B 17555C Effective November 1999 Page A8...
Страница 81: ...I B 17555C Effective November 1999 Page B5 Fig B 2 Digitrip 3010 3020 Dimensions Inches...
Страница 83: ...I B 17555C Effective November 1999 Page B7 Fig B 3 Digitrip 3010 3020 Typical Wiring Diagram...
Страница 89: ...I B 17555C Effective November 1999 Page B13...
Страница 90: ...I B 17555C Effective November 1999 Page B14...
Страница 91: ...I B 17555C Effective November 1999 Page B15...