tabel proteksi
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TABEL PROTEKSI
TABEL PROTEKSI PADA SALURAN TRANSMISI
Macam Proteksi Uraian
Over current Protection
- Klas waktu dan Arus
- Directional atau
tidak directional
Merupakan pengaman utama untuk
saluran distribusi dan back-up
untuk saluran utama, dimana
pengaman utamanya adalah jarak
atau tipe lain yang cepat
Waktunya minimum rele inverse
definite dipilih untuk sistem waktu
yang sempit
Rele Instantaneous untuk arus
Proteksi gangguan ke tanah Pengaman gangguan ke tanah
terpisah yang ditambahkan hanya
untuk kebutuhan pengaman
gangguan phasa ke tanah
Pengaman Jarak Lebih cepat dari pengaman over
current. Kombinasinya tergantung
pada panjang saluran yang on
Pilot wiredifferential protection Untuk saluran transmisi yang
panjang (minimal 10 km)
Carrier Current Protection Untuk saluran transmisi yang
panjang dan sering terbukanya CB
TABEL PROTEKSI PADA GENERATOR
Teknik Elektro ITS 1
TABEL PROTEKSI
No
.
Macam Proteksi Kurang
dari
1 MW
Diatas
1 MW
Diatas
1 MW
Diatas
1 MW
1. Differential * *
2. Restriced earth fault * *
3. Stator turn to turn fault *
4. Time Over Current * *
5. Temperature
(thermo-detector)* * *
6. Negative sequence
Current* * *
7. Loss of Load * *
8. Loss of input-anti-
Motoring* * *
9. Loss of field * *
10. Loss of synchronism * *
11. Over speed*
Hanya untuk
hydrogenerator
12. Over voltage*
Hanya untuk
hydrogenerator
13. Rotor earth fault * *
14. Back-up overcurrent * * *
15. Bearing temperature * *
16. Bearing insulation *
Teknik Elektro ITS 2
TABEL PROTEKSI
TABEL BEBARAPA KONDISI TIDAK NORMAL
DAN SISTEM PENGAMANNYA
No. Kondisi tak normal Pengaruh Pengaman
1. Panas Kelebihan
beban
- beban naik terus
- sistem pendingin
rusak
Kumparan stator
dan isolasi rusak
karena terlalu
panas
Thermocouples atau
resistance
thermometer
imbedded in stator
slots and cooling
system.
Stator overload
protection with
overcurrent relay
2. Gangguan diluar
generator
Beban tidak
seimbang,
tekanan pada
kumparan dan
poros, panas
berlebihan yang
memperpanjang
hubung singkat.
Negative sequence
protection untuk
mesin yang besar.
Overload protection
untuk mesin yang
kecil
3. Gangguan pada
stator:
- antar phasa
- phasa ke tanah
- inter turn
Kumparan
terbakar,
pengelasan pada
inti laminasi, mati
Blased differential
protection, sensitive
earth fault protection,
inter turn fault
protection
Teknik Elektro ITS 3
TABEL PROTEKSI
No. Kondisi tak normal Pengaruh Pengaman
4. Rotor gangguan ke
tanah
Satu gangguan
tidak berbahaya,
kedua gangguan
menyebabkan
ketidakseimbanga
n tekanan magnet
yang
menyebabkan
kerusakan shaft
dan bearing.
Rotor earth-fault
Protection
5. Kehilangan medan
magnet
- CB medan magnet
trip
Generator jalan
sebagai generator
induksi yang
mendapat eksitasi
arus dari bus-bar.
Kecepatan
bertambah
Loss of field atau field
failure protection
6. Generator berubah
jadi motor.
Saat inpit dari prime
mover berhenti,
generator mangambil
daya dari bus-bar dan
berubah menjadi
motor sinkron pada
keadaan yang sama
Pengaruhnya
tergantung pada
prime mover yang
on dan jumlah
daya yang diambil
dari bus-bar saat
berubah jadi
motor
Reverse power
protection by
directional power
relays detect the
reversal of power
7. Over voltage Isolasi terbakar Ligthning arrester
tersambung pada
terminal generator.
Teknik Elektro ITS 4
TABEL PROTEKSI
TableTypes of protection for Generators and their setting
Generator Rating
1
Type of Drive
2
Type of protection used
3
Suggested fault current setting
4
Protection for exciter circuit and neutral
5
Below 1000 KVA
Steam Turbine
1.fault relay
2.current relay
3.(only for back pressure turbines)
20 percent full load current 125 percent full load current 10 to 20 percent of its normal power rating
1. Neutral isolating switch
2. Field switch in the exciter field circuit
Steam Engine
or Diesel Engine
1. Time graded earth fault relay
2. Time graded over current relay
3. Reverse power
20 percent full load current 125 percent full load current 10 to 20 percent of its normal power rating
1. Neutral isolating switch
2. Field switch in the exciter field circuit
1000 KVAto
5000 KVA
Steam Turbine
1. Balanced earth fault relay or
Differential protection (Merz-Price)2. Reverse power
(only back pressure turbine)
10 to 25 percent full load current 10 to 25 percent full load current 10 to 25 percent full load current
1. Neutral isolating switch
or Automatic neutral breaker
1000 KVAto
5000 KVA
Water Turbine
1. Balanced earth fault relay or
Differential protection (Merz-Price)2. over voltage
protection
10 to 25 percent full load current 10 to 25 percent full load current 10 percent of normal voltage
1.For unattended elations, protection against field failure Setting 20 to 30 percent of the normal excitation.2.Neutral isolating switch or automatic neutral breaker
Teknik Elektro ITS 5
TABEL PROTEKSI
Generator Rating
1
Type of Drive
2
Type of protection used
3
Suggested fault current setting
4
Protection for exciter circuit and neutral
5
Above 5000 KVA
Steam Turbine
1. Differential protections (Merz-Price)
or Time graded earth fault
relay2. Phase unbalance
3. Reverse power (only back pressure turbine)
10 to 25 percent full load current 20 percent full load current 10 to 25 percent negative phase sequence only 10 to 25 percent full load current
1. Field earth fault for protecting 96% of the field winding (only for generator above 20.000 KVA)2.Automatic field suppression switch
3.Automatic neutral breaker.
Water Turbine
1. Differential protections or Time graded earth fault
relay2.Over voltage
10 to 25 percent full load current 20 percent full load current 10 percent of normal voltage
1.For unattended station protection against field failure, Sotting 20 to 30 percent normal excitation2.Filed earth fault for protecting 96% of the field winding.3. Automatic field suppression switch3.Automatic neutral breaker.
Teknik Elektro ITS 6
TABEL PROTEKSI
Table Power Transformer Protection
Abnormal Condition Protection Remarks
Incipient faults below oil level
resulting in decomposition of oil,
faults between phases and between
phase and ground
Buchholz relay sounds
alarm (Gas actuated relay)
Buchholz relay used for
transformer of rating 500 KVA
and above
Large internal faults phase to phase,
phase to ground, below oil level
1. Buchholz relay trips the
circuit breaker
Buchholz relay too slow and less
sensitive
2. Merz Price percentage
differential protection
3. High speed high set
overcurrent relay
Merz Price percentage
differential protection used for
transformers of and above 5
MVA
Earth faults
1. Merz Price percentage
differential protection
For transformer of and above 5
MVA
2. Earth fault relay a. Instantaneous Restricted
E.F. Relay
b. Time lag E.F Relay
Through faults
1. Graded time lag over
current relay
Protection of distribution
transformer
2. H.V Fuses Small distribution transformer up
to 500 KVA
Overloads
1. Thermal overload relay
2. Temperature relays
sound alarm
Generally temperature indicators
are provided on the transformers.
Temp. increase is indicated on
control board also. Fans started
at certain temp.
Teknik Elektro ITS 7
TABEL PROTEKSI
Abnormal Condition Protection Remarks
High Voltage Surges due lightning,
switching
1. Horn gaps Not favoured for important
transformer
2. Lightning arresters In addition to L.A.s for incoming
lines
Small distribution transformer
Only fuses for earth fault protections and phase fault
protection. Overload protection generally not
provided
For more important transformers of about 500 KVA
Over current relays
Instantaneous earth fault relays
Transformers in important locations ratings 500
KVA and above
Restricted earth fault protection
Over urrent protection
Buchholz relay
Teknik Elektro ITS 8
TABEL PROTEKSI
Table Protection of Large Generator Transformer Unit
Protection of Generator
Transformer together
Generator-transformer overall differential protection*
Generator protection Generator differential protection*
Stator earth fault protection*
Negative phase sequence protection against-
unbalanced loading***
Inter-turn fault protection
Reverse power protection
Field failure protection**
Rotor earth fault protection
Temperature sensors in slots***
Overcurrent relays in stator and rolar circuits
Lightning arrester for generator overvolatage protection
Protection of unit
auxiliary transformer
Differential protection*
Restricted earth fault protection*
Buchholz relay
Overcurrent protection
Winding and oil temperature sensors
Protection of main
transformer
HV overcurrent protection*
HV Restricted earth fault protection*
Buchholz relay
Winding and oil temperature sensors
Lightning arresters on HV side
Teknik Elektro ITS 9
TABEL PROTEKSI
Protection of Generator
Transformer together
Generator-transformer overall differential protection*
Preventive measures
sound alarm on control
panel
Continous monitoring of outlet temperature of gaseous
or liquid coolants
Flow monitors
Low noiler pressure alarm/trip
Lubrication oil failure
Emergency trip
Low vacuum
* Trip generator c.b., close throttle valves, open field c.b.,open auxiliary c.b
** Close emergency throttle valves main c.b. opened only after operation of
interlocking reverse power relay
*** Trip main circuit breaker only
Teknik Elektro ITS 10
TABEL PROTEKSI
Protection Chart for Induction Motors
Abnormal
condition
Alternate forms of protections
from which choice is made
Remarks
Overload - Overload release
- Thermal overload relays
- Inverse overcurrent relays
- Miniature circuit breaker
with built in trip
- overload protection givem for
almost all motors
Phase fault and
earth faults
- HRC fuses
- High set instantaneous
overcurrent relays
- Differential protection
- Differential protection
becomes economical for
motors above about 1200
HP. Below this high set
instantaneous protection is
preferred
Undervoltage - undervoltage release
- undervoltage relays
- undervoltage release
incorporated every
starter
- undervoltage relays used
in certain applications
Unbalanced
Voltage
- Negative phase sequence
relay
- only in special
applications
Reverse phase
sequence
- Phase reversal relays - Generally at support
Teknik Elektro ITS 11
TABEL PROTEKSI
point
- Prevents reverse of
running
Abnormal
condition
Alternate forms of protections
from which choice is made
Remarks
Single Phasing - Usual thermal overload
relays
- Special single phase
preventer
- Recently developed
static single phasing
devices becoming
popular
Stalling - thermal relays
- Instantaneous O.C Relays
Rotor Faults - Instantaneous overcurrent
relays
- only for motors
Teknik Elektro ITS 12
TABEL PROTEKSI
Teknik Elektro ITS 13