Does it make sens to use a 60Hz line filter

[Piet_de _Pad]

Dear solar enthusiast,
I'm working on a protection device against incoming bad electricity like spikes, under and over voltage and noise. Below low is a design I made. I would like to hear your ideas about this house protection device. In particular, my question "does it make sens to use a 60Hz Low pass filter at the entrance of a house" I would like to know more about.

To build this protection, I use four components

1. An Under and Overvoltage protection with time delays.
2. An 40A contactor
3. An AC Surge Protection Device, SPD
4. A 60 Hz low pas filter for 40Amp

The UV and OV protection in combination with the Contactor guarantees a stable AC voltage between two voltage levels. It also provides the time delays returning no normal operation after the occurrence of a UV or OV event.
The SPD shortcuts possible voltage spikes on the AC grid to earth.
The filter is a more complicated part. There are EMI filter for three-phase and single phase system exits, but not for split phase. Furthermore, I'm not convinced if an EMI filter at the main feed of a house is a good idea since most EMI is produced in the house and not coming in from the grid. It does block the EMI from the house into the grid. To block low frequent noise coming in from the grid and going out to the grid from the house a special designed low pass filter is needed and I haven't found them yet.

Let me know what you think and what you know.
Thanks.

 

[BentleyJ]

1 & 2) Hybrid inverters already have both these items built in. Installing a solar back-up system would be the recommended method of gaining this function if your electrical service is unreliable.
3) Surge Protection (TVSS) is always recommended. Should be standard on every service panel as far as I'm concerned.
4) Low Pass line filter would not necessarily be helpful if inserted per the drawing, in front of the Dist Panel as a whole house system. A line filter of that type would more likely be used to isolate certain parts of an electrical system. For example, I've used a 20A TDK filter (yes, it works on split phase with L1 & L2 only) in an Enphase microinverter combiner box so the PLC communication to the Envoy is isolated from the Subpanel as well as the rest of the electrical system which has an Insteon home automation system that also uses PLC to communicate with devices.

 

[Warpspeed]

The UV and OV protection in combination with the Contactor guarantees a stable AC voltage between two voltage levels.

No it won't.
UV and OV will just disconnect the supply leaving you with nothing.
Zero volts and a total blackout is not a stable AC supply.

 

[stromy]

SPD setups need a more complex design that fits the local electrical system in a house. You cannot put it "in a box".
Mains filters should be as close to the noise source as possible. Mains filters are typically optimized for a particular noise source.
If you use a mains filter, it has to be placed such, that it is protected by the SPD.
You can use a 3PH mains filter for 2PH or 1PH.

 

[Piet_de _Pad]

1 & 2) Hybrid inverters already have both these items built in. Installing a solar back-up system would be the recommended method of gaining this function if your electrical service is unreliable.
3) Surge Protection (TVSS) is always recommended. Should be standard on every service panel as far as I'm concerned.
4) Low Pass line filter would not necessarily be helpful if inserted per the drawing, in front of the Dist Panel as a whole house system. A line filter of that type would more likely be used to isolate certain parts of an electrical system. For example, I've used a 20A TDK filter (yes, it works on split phase with L1 & L2 only) in an Enphase microinverter combiner box so the PLC communication to the Envoy is isolated from the Subpanel as well as the rest of the electrical system which has an Insteon home automation system that also uses PLC to communicate with devices.

Thanks for your reaction i take that with me.

 

[Piet_de _Pad]

No it won't.
UV and OV will just disconnect the supply leaving you with nothing.
Zero volts and a total blackout is not a stable AC supply.

Thanks for your reaction i take that with me.

 

[Piet_de _Pad]

SPD setups need a more complex design that fits the local electrical system in a house. You cannot put it "in a box".
Mains filters should be as close to the noise source as possible. Mains filters are typically optimized for a particular noise source.
If you use a mains filter, it has to be placed such, that it is protected by the SPD.
You can use a 3PH mains filter for 2PH or 1PH

Thanks for your reaction i take that with me.

 

[rearden]

How effective would a whole system line filter be for improved protection against spikes, surges and EMI. Especially to address: lightning, EMP, switching spikes and EMI/RFI generated by the inverter.

The line filter would not replace the TVS devices, but supplement them. Instead of viewing a spike only as an increased line voltage, but view it as a frequency that can be filtered. I believe Furman uses this approach in their higher end surge equipment (PST-8D) and the ISOBAR line by Triplite includes significant filtering.

I have a hybrid inverter which is at the end of the power line. One of my in-panel Type 2 surge protection devices is behind a 35a circuit breaker. That breaker trips several times per year, so I know I get frequent significant spikes. I have multiple levels of TVS devices, but it seems like good financial and engineering practice to try to protect the system in additional ways. $200 spent on a filter improve the probability that a $10k+ system works when it is needed (when the power goes out after a storm). If you look through the literature about hardening of facilities against various forms of EMP, they include lots of filtering in their designs, not just GDT, MOV and zeners. The EMP hardened SolArk system includes a number of ferrites for use on the DC solar inputs (plus whatever they do inside the box).

A possible filter could be as cheap and simple as an FT-240-(61,43,31) ferrite slipped around the entrance feed (CM) with a few Y1/Y2 rated capacitors line to ground or line to line.

or products like Astrodyne RP135-200 or Schaffner FN612 or CorCom AYC10B or VS/TE line at appropriate amperages.

Has anyone added line filters to their system?

 

[Hedges]

A line filter is usually to suppress RF noise in the 150 kHz to 1 GHz range below conducted emission limits of 1 mV.

https://www.digikey.com/en/products/detail/schaffner-emc-inc/FN612-6-06/1928789

https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/2482/FN612%20Series.pdf

Note location of Cy capacitors in above diagram. I think OP's diagram is backwards compared to normal usage suppressing emissions, instead improves immunity to noise coming from outside.

But this is only for relatively low level interference. The components don't have enough energy storage to filter high energy surges that could cause damage. And they don't do much if anything at low frequencies.

GDT, MOV, etc. are designed for high power events, but they can handle only a finite amount of energy. Not continuous. They can provide some degree of protection from coupled lightning or EMP. I don't think added ferrites do much.

Perhaps a power transformer reconfigured as a choke could do more, having lots of heavy iron. Add big capacitors as well for a very large EMI filter. Note that big caps will carry reactive current.

For EMP, there is the issue of near DC, which saturates transformers.

If you really want to connect to the grid but be isolated from electrical events, consider a motor-generator. With disconnect if DC appears.