Solutions   for   Protecting   andManaging   the   Electrical   Network

VOLTAGE   AND   FREQUENCY   RELAYS

Voltage and Frequency protection relays

Voltage and frequency protections relay perform voltage monitoring for electrical networks and/or islanding, or load shedding for no priority loads. So when the electrical supply of a switchboard is performed by two transformers feeding each a half-busbar, in case of a transformer failure, it is possible to perform automatic load transfer from a half-busbar to the other.
Zero sequence over voltage relays protect three-phase networks with isolated or high impedance earthed neutral against earth faults.

Below the list of CEE products dedicated to the voltage and frequency monitoring.

  Device Series ANSI Description
NP V911 NP 900 59, 27, 59N, 59P/27P/47, 78, 81O/81U, 81R, 60, 74TC, 86 Busbar voltage & frequency protection IED
NPU800 NP 800 27, 27P, 47, 59, 59N, 74TC, 81, 86 Voltage and Frequency Relay
NPU800R
NPU800RE
NP 800 R 27, 27P, 47, 59, 59N, 74TC, 81, 86 Voltage and Frequency Relay
NPUH800 NP 800 59N, 86, 74TC Residual Overvoltage Relay (Neutral Displacement Relay)
NPUH800R NP 800 R 59N, 86, 74TC Residual Overvoltage Relay (Neutral Displacement Relay)
TMS 700 PROCOM 27, 59, 59N Digital multi-function voltage relay
TMS 7000 PROCOM 27, 27P, 47, 59, 59N Digital multi-function voltage relay with advanced functionalities
HDG 7020 STATIC 81 Frequency relay
TTB 7000 STATIC 27DC, 59DC Measuring relay for DC applications
TTG 7000 STATIC 27, 59, 59N Undervoltage and overvoltage relays
TTGB 7031 STATIC 60 Voltage balance relay