3EL / 3EQ / 3EP — station surge arresters up to 800 kV
3EL, 3EQ and 3EP are three families of station AC surge arresters for substations of classes from 3 to 800 kV. The arresters protect transformers and reactors, circuit breakers, generators, motors, capacitors, bushings and switchgear from lightning and switching overvoltages. They are installed in 6–750 kV substations, in switchgear and on overhead lines.
- Network class
- from 3 kV to 800 kV (the portfolio as a whole up to 1200 kV)
- 3EL (3EL1/2/3/5)
- silicone housing, Cage Design™ construction (frame of fiberglass rods), up to 800 kV
- 3EQ (3EQ1/3/4)
- silicone on a fiberglass tube, directional pressure relief, up to 800 kV
- 3EP (3EP3/4/5/6)
- porcelain housing, directional pressure relief, up to 800 kV
Price, availability and lead time on request. We help with analogue selection, customs clearance and delivery.
Description
The company has made surge arresters since 1925, and the portfolio as a whole covers networks up to 1200 kV, including HVDC and FACTS. The plants are in Berlin (Germany) and Wuxi (China). The active part is a column of metal-oxide varistors without spark gaps. They have high energy capability and a low protection level, withstand long current impulses and, according to the manufacturer, keep their characteristics throughout the service life.
3EL (types 3EL1, 3EL2, 3EL3, 3EL5) has a silicone housing and Cage Design™ construction. The varistors are clamped by a frame of pre-stressed fiberglass rods, and silicone is molded directly onto the varistors and the frame, without voids or bubbles. There are no partial discharges and no moisture ingress. In an overload the arc exits through the soft shed, and internal parts are not thrown out. These arresters are light and strong, and are used both in substations and on lines.
3EQ (3EQ1, 3EQ3, 3EQ4) has a silicone housing on a fiberglass tube with flange seals and directional pressure relief devices. Mechanical strength is very high, so the arrester can also serve as a post insulator, including in seismic and windy regions. 3EP (3EP3, 3EP4, 3EP5, 3EP6) is built in a porcelain housing with a fiberglass frame and directional pressure relief. The aluminum flanges are set in sulfur cement, and the strength of the joint is higher than that of the porcelain itself.
The silicone insulation is only high-temperature (HTV) or liquid (LSR) vulcanized. It stays hydrophobic for the whole service life, resists UV, ozone and erosion, and is flame-retardant and self-extinguishing under IEC 60707 and UL94 V-0, operating from −60 to +200 °C. The arresters are therefore suitable for coastal, desert and heavily polluted areas where salt fog or industrial dust quickly spoils EPDM rubber.
Surge counters and the monitoring systems 3EX5 and Sensarrester are offered with the arresters. The products comply with international IEC standards. An example of application is the 400 kV Bidingen substation, where 3EQ4 arresters protect the switchgear. The seals of all types do not let moisture in, and moisture is what most often takes arresters out of service in old designs, so the porcelain 3EP also work for decades without failures.
Technical specifications
| Network class | from 3 kV to 800 kV (the portfolio as a whole up to 1200 kV) |
|---|---|
| 3EL (3EL1/2/3/5) | silicone housing, Cage Design™ construction (frame of fiberglass rods), up to 800 kV |
| 3EQ (3EQ1/3/4) | silicone on a fiberglass tube, directional pressure relief, up to 800 kV |
| 3EP (3EP3/4/5/6) | porcelain housing, directional pressure relief, up to 800 kV |
| Varistors | metal-oxide (MOV), without spark gaps |
| Silicone | HTV/LSR, −60…+200 °C, IEC 60707 / UL94 V-0 |
| Production | Berlin (Germany), Wuxi (China) |
Request a price and lead time
3EL / 3EQ / 3EP — station surge arresters up to 800 kV. We reply within one business day.
Or email sales@usk.ua or call 044 339-50-20.
Customs codes
| UKTZED (Ukraine) | 8535 40 00 00 |
|---|---|
| HS, 6 digits | 8535 40 |
| CN (EU) | 8535 40 00 |
| HTSUS (USA) | 8535 40 00 00 |
| China customs tariff | 8535 40 00 00 |
Codes are for reference: the final code is determined at declaration for the specific model.
Questions and answers
Which arrester family should be chosen for a seismic region?
3EQ on a fiberglass tube suits such conditions, and its mechanical strength allows the arrester to be used also as a post insulator. The family is made up to 800 kV.
Can 3EL arresters be installed on lines?
Yes, 3EL arresters are light and mechanically strong, so they are used both as station and as line arresters. The Cage Design™ construction rules out partial discharges and moisture ingress.
How does 3EP differ from silicone arresters?
3EP has a porcelain housing with a fiberglass frame and directional pressure relief. It is made in types 3EP3, 3EP4, 3EP5 and 3EP6 up to 800 kV.
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