XMR-C, XC20, NC20, NC020 protection of capacitor banks and harmonic filters
The XMR-C, XC20, NC20 and NC020 relays protect shunt capacitor banks and higher harmonic filters. The multifunction XMR-C terminal belongs to the XMORE platform, and the other three relays are separate lines. They work in reactive power compensation installations of 6–35 kV and at industrial substations.
- Protected object
- shunt capacitor banks and harmonic filters (bank + air core reactor)
- Schemes
- star (earthed/unearthed), double star, delta, H-bridge (XMR-C)
- Capacitor type
- with internal/external fuses or without
- RMS measurement
- harmonics up to the 50th (XMR-C), 52nd (XC20), 11th (NC20)
Price, availability and lead time on request. We help with analogue selection, customs clearance and delivery.
Description
The task of protecting capacitor banks becomes more acute because the share of loads that generate harmonics is growing in industry and power grids, in particular thyristor and frequency converters and static compensators (TCR, thyristor controlled reactors, and TSC, thyristor switched capacitors). A harmonic filter consists of a capacitor bank and a series connected air core reactor and absorbs the harmonic currents of the load. The manufacturer produces several generations of relays for this. They are used in reactive power compensation installations of 6–35 kV, in filter-compensating devices of metallurgical and chemical enterprises and at grid company substations.
The XMR-C is intended for protection, measurement and supervision of capacitor banks and filters. It works with single star (earthed or unearthed), double star (earthed or unearthed), delta and H-bridge schemes. Capacitor elements may have internal or external fuses or none. The relay includes a method of compensating the natural unbalance of the neutral current. Protections 37, 49, 59H and 50/51 work on the RMS value of phase currents with harmonics up to the 50th taken into account. The measurement circuits are three phase currents and the neutral unbalance current with a rating of 1 or 5 A, three phase voltages and the zero-sequence voltage with a programmable rating of 50–130 V. There are also breaker failure protection, supervision of CT (74CT), VT (74VT) and trip circuits (74TCS), and programmable logic. The oscillograph records 128 samples per cycle, and the accuracy of the protection elements is supported by measurement at 64 samples per cycle.
The XC20 and NC20 protect banks in earthed star, unearthed star (with a resistor at the output of the unbalance VT) and unearthed double star schemes. Protections 37, 49 and 50/51 work on the true RMS value, with harmonics taken into account up to the 52nd in the XC20 and up to the 11th in the NC20. The relays have undervoltage and undercurrent protections, negative-sequence overcurrent protection, phase and earth overcurrent protection, overvoltage protection, breaker failure protection, and supervision of CT and trip circuits. The HW PACK and SW PACK packages are optionally available, and setting is done through the USB-B port in the ThyVisor software.
The NC020 is intended for harmonic filters. It has breaker failure protection, negative-sequence protection, voltage and phase current protections, and communication with the upper level is over Modbus RTU through RS232.
Technical specifications
| Protected object | shunt capacitor banks and harmonic filters (bank + air core reactor) |
|---|---|
| Schemes | star (earthed/unearthed), double star, delta, H-bridge (XMR-C) |
| Capacitor type | with internal/external fuses or without |
| RMS measurement | harmonics up to the 50th (XMR-C), 52nd (XC20), 11th (NC20) |
| Functions | 37, 49, 59H, 50/51 RMS, neutral unbalance with compensation, 46, 59, 27, breaker failure protection, 74CT, 74VT, 74TCS |
| XMR-C inputs | 3 currents + unbalance current (1/5 A), 3 voltages + Uo (50–130 V) |
| Communication | USB-B (ThyVisor); NC020 Modbus RTU RS232 |
Request a price and lead time
XMR-C, XC20, NC20, NC020 protection of capacitor banks and harmonic filters. We reply within one business day.
Or email sales@usk.ua or call 044 339-50-20.
Questions and answers
Which capacitor bank schemes does the XMR-C support?
Single star (earthed or unearthed), double star (earthed or unearthed), delta and H-bridge. Bank elements may have internal or external fuses or no fuses.
What input signal ratings does the XMR-C have?
The three phase currents and the neutral unbalance current have a rating of 1 or 5 A. The three phase voltages and the zero-sequence voltage have a programmable rating of 50–130 V.
Up to which harmonic do the relays take the signal into account in measurement?
XMR-C up to the 50th, XC20 up to the 52nd, NC20 up to the 11th. Protections 37, 49 and 50/51 work on the RMS value of phase currents.
Similar equipment from other manufacturers
