PROTECTION RELAYS
MEASUREMENT TRANSDUCERS
A2 PROTECTION & CONTROL DEVICES (ENEL SPECS)

PROTECTION & MEASURING SYSTEMS

OTHER DEVICES

Sigma-N are the digital protection relays and measurement transducers developed and manufactured by SEB
for M.V. generation and distribution plants.







IFX4N
Overcurrent and earth fault relay, in accordance to CEI 0-16 norm.
(50-51-51N-64S-64T)
IFD4N
Overcurrent and directional earth fault relay, in accordance to CEI 0-16 norm.
(50-51-67N)
DIA4N Interface device for self-producers, in accordance to CEI 0-16 norm
(59-27-59Vo-81)
IFX4NR
Overcurrent and earth fault relay with auto-recloser
(50-51-51N-64S-64T-79)
UAR4N
Voltage protection relay
(59-27-59Vo-64S)
Voltage balance relay (60)
IAD3N
Directional earth fault relay
(67-67N-32)
UHF4N Protezione di tensione e frequenza
(59-27-59N-81-df/dt)
IMT4N
Motor protection relay
(49-50-51R-46-51N-37-66)
ZFD8N
Directional overcurrent and earth fault relay or minimum impedance relay
(67-67N-50-51-59Vo-79-21)
HAR1N
Frequency relay
(81<>-59/81-dF/dt-dphi)
ING4N
Amperomertrical generator relay
(46-49-50-51-51N)
PQR4N
Generator relay
(40-64R-32)
IDG8N
Generator differential relay
(87G-64Ss)
IDT8N
Overall differential relay
(87T)
SCK4N Synchro check relay
(25)
SCK4N-D Synchro check relay
(25)
CU90N Voltage regulator for tap-changer
(90)
UHR4N 100% stator earth fault realy
(64S-100%)
ZFP8N Generator out of step realy
(78)
IBF4N Breaker failure device
IDB4N Busbar differential relay
(87B)
IDM8N Machine differential relay, according to Enel spec. DV6903RO - Ed.1
(87T)
IFF4N Overcurrent protection
RFI category: 794/410 794/502
IFF4E Overcurrent protection
RFI category: 794/612

Sigma-L are the small size digital protection relays developed and manufactured by SEB
for M.V. distribution plants.


IFX4L
Overcurrent and earth fault relay in accordance to CEI 0-16 norm
with Data Logger.
(50-51-51N-64S-64T)

Sigma-S are the low cost digital protection relays developed and manufactured by SEB
for M.V. generation and distribution plants.


IFX3S
Overcurrent and earth fault relay in accordance to CEI 0-16 norm
with Data Logger.
(50-51-51N)