With all of the improvement and upgrade projects underway at SZ1A, equipment donations from fellow HAMs and colleagues, sponsorships, much volunteer work with a lot of effort and passion put in, both from veteran and newer members, and, on the occasion of the installation of the new three-phase power supply, I decided to contribute to the upgrade effort. I felt that I needed to do something to help, as there are so many needs and the station is the result of the efforts of all of us. Only if we all contribute to this effort, each of us in any way possible, then we will be able to succeed in making our vision a reality. So I took the initiative to purchase and donate to the station specialized lightning protection equipment, in order to protect, as much as possible, our valuable equipment and facilities.
So we recently purchased and installed:
- State of the art heavy-duty three-phase “Lightning Arrestor” for the general distribution power panel (Surge Protection Device)
- Fourteen Special Surge Protection Multi-socket Power Strips and
- Nine Special Surge Protection Single Sockets (more on these below).
The station is the result of the efforts of all of us. Only if we all contribute to this effort, each of us in any way possible, then we will be able to succeed in making our vision a reality.
Lightning Arrestor – Surge Protection Device
It is from ΑΒΒ, and it is the model ABB QuickSafe® OVR T1-T2 3N 12.5-275s P QS, which belongs to the new generation of heavy-duty lightning protection products, as it has the ability to disperse repeated surges without the need for replacement, and it has the best specifications in its category. It protects against extreme differences of potential in all three phases and in the neutral conductor, in all combinations (L-N / L-PE / N-PE). That is, if surge shocks occur in any conductor, the potential will be dispersed to ground and will not infiltrate into the internal electrical installation. It has quite a high surge protection capability, low activation value (at only 1.4kV) and instantaneous response time (<25ns).
It is already installed in the new three-phase distribution panel, and protects the overall electrical installation of the entire station. It has a special new type of MOV varistor in replaceable cartridges, one for each phase with an indicator for normal & reserve operation, and is type T1 & T2.
That is, it is designed to protect against overvoltage surge “pulses” caused by direct lightning strikes up to 50kA (with pulse waveform 10 / 350 µs – level T1), and also from indirect strikes up to 80kA (with pulse waveform 8 / 20 µs – level T2), and has a total “capability” of 100kA.
Special Multi-socket & Single-socket Surge Protectors
They are made by “Crystal Audio”, an internationally renowned company, founded in Greece, that specializes in hi-end audio systems. They are designed as additional protection for very “sensitive” electronic devices such as amateur radio equipment in the shack, televisions, audio systems, etc. – of type T3 (surge pulse waveform 1.2 / 50 µs). They have varistors and a GDT (Ionizing Gas Discharge Tube) that protect the overall wiring of the equipment connected to them – namely Phase to Neutral (L-N), Phase to Earth (L-PE), and Neutral to Earth (N-PE), most SPDs of this type on the market only provide protection for the Phase conductor to Earth. They also include a thermal fuse & safety switch. Surge shock protection is published by the manufacturer at 45kA – 1300J
Perhaps one of its most important features, especially for us, is that it has a built-in EMI / RFI filter, which filters RF from the supply line – something especially important for a multi-radio contest station (less reception noise, less RFI effects when transmitting, and less strain on connected devices). Most SPD protection sockets on the market today do not have any RF filtering capability whatsoever. The nominal RF filtering value published by the manufacturer is 70dB!!
Specifically for the needs of the station we have purchased the following:
- Nine single-socket CRYSTAL AUDIO CP1-1300-70 special surge protection device with 70dB EMI / RFI filtering, 16A supply each, for the stations’ linear amplifiers (planned positions and spares).
- Ten five-socket power-strips CRYSTAL AUDIO CP5-1300-70 special surge protection device with 70dB EMI / RFI filtering, 16A, for complete coverage of our equipment in each row of operating position benches in the station radio room.
- Four six-socket power-strips CRYSTAL AUDIO CP6-1300-70 special surge protection device with 70dB EMI / RFI filtering, 16A, for our equipment in the server room of the station & workbench in the shack.
Additionally, you can refer to the following links for more information on the above products:
Finally, for those of you who would like to further your knowledge on lightning surge protection, have a look at the following very interesting guide from ABB:
Also don’t forget to read the very interesting article written by our dear colleague Kostas Stamatis – SV1DPI, on lightning protection of an amateur radio station.
I hope all of the above protective equipment will never be actually needed, but as the saying goes, “it’s better to be safe than sorry“, and I think we can now feel more protected from Zeus’s Lightning Bolt – hi hi !!
73 to all of you,
Andy – SV1DKD
