Cheap Insurance: Surge Protection

[Watts Happening]

For those of us with hybrid inverters and/or any “sensitive electronics” which is seemingly anything and everything these days, this feels like very cheap insurance.

There are many options from many companies, in this case I just grabbed an off the shelf surge protector from Square D that matches my main service panel. Installation was quite literally 30 seconds, same as installing a breaker with a pigtail connected to the neutral bus bar.

In general, this provides surge protection to the entire house, up to 25,000 amps. Is this a perfect solution? Will it provide against any and all surges? Certainly wouldn’t bet my life on it. However I would say it’s vastly better than nothing and at $80 it feels like a no brainer to protect my Sol-Ark 15k.

If you’ve got a similar inverter always connected to the grid, I think it’s wise to offer it some form of protection at such a reasonable price.

 

[DIYrich]

I installed the Siemens FSPD in my main panel. Unfortunately, the Sol-ark is between the meter and main panel. Some day I might try to figure out how to wire the Midnight Solar version between the meter and Sol-ark.

 

[Watts Happening]

I installed the Siemens FSPD in my main panel. Unfortunately, the Sol-ark is between the meter and main panel. Some day I might try to figure out how to wire the Midnight Solar version between the meter and Sol-ark.

That’s an interesting scenario I hadn’t thought of. I’m not aware of a product designed for it off the top of my head, but wouldn’t be shocked if someone made one.

 

[Hedges]

I just put in the same, because inspector said whole-house surge protector was required.



I would have bought the 50kA rather than 25kA rated model (house on top of a hill and fed by overhead lines), but only available Plug-On-Neutral not compatible with my model.

https://www.lowes.com/pd/Square-D-QO-50-KA-Indoor-Surge-Protective-Device/1000642897

I was going to do one for solar stuff, but picked these up to satisfy inspector. Ever the cheapskate, I bought a 5-pack on eBay, stuffed one in this panel, one in panel feeding electronics lab at other place, will put one in main 200A panel when installed in Oakland.

The actual PV feed for Oakland bypasses these breaker panels straight through a 100A switch, so will put something there too, maybe higher capacity. Or something at the main 200A breaker that feeds everything will need suitable OCP.)

I installed the Siemens FSPD in my main panel. Unfortunately, the Sol-ark is between the meter and main panel. Some day I might try to figure out how to wire the Midnight Solar version between the meter and Sol-ark.

Midnight or one like this:

https://www.lowes.com/pd/Square-D-SurgeArrest-25-KA-Indoor-Outdoor-Surge-Protective-Device/4363149

Use a tap like Polaris on the wire, feed through a fuse or breaker (need to mount somewhere, maybe DIN rail in a box that has the space.)

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

 

[Watts Happening]

I just put in the same, because inspector said whole-house surge protector was required.

View attachment 198128

I would have bought the 50kA rather than 25kA rated model (house on top of a hill and fed by overhead lines), but only available Plug-On-Neutral not compatible with my model.

https://www.lowes.com/pd/Square-D-QO-50-KA-Indoor-Surge-Protective-Device/1000642897

I was going to do one for solar stuff, but picked these up to satisfy inspector. Ever the cheapskate, I bought a 5-pack on eBay, stuffed one in this panel, one in panel feeding electronics lab at other place, will put one in main 200A panel when installed in Oakland.

The actual PV feed for Oakland bypasses these breaker panels straight through a 100A switch, so will put something there too, maybe higher capacity. Or something at the main 200A breaker that feeds everything will need suitable OCP.)



Midnight or one like this:

https://www.lowes.com/pd/Square-D-SurgeArrest-25-KA-Indoor-Outdoor-Surge-Protective-Device/4363149

Use a tap like Polaris on the wire, feed through a fuse or breaker (need to mount somewhere, maybe DIN rail in a box that has the space.)

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

Funny, exact same reason I did the 25kA and not 50kA!

 

[k490]

Cheap insurance I like how they have the LED tells you when the MOV's are worn out. They can only take so many surges before they become useless. Used to replace power strips when I was a PC tech years ago every 3 years after one MOV wore out and caused smoke in the office. Usually with ever PC refresh we would put a new power strip in.

Think I'm going to by a Ditek according to reviews the Ditek has a TP-MOV Thermally protected mov that disconnects the mov from its circuit before catastrophic failure occurs. This way if you have a 2nd surge after the first one it protects you from that 2nd surge as well.

 

[Skypower]

I have two Square D 80kA units. One on the grid of the inverter and the other on the load side. Peace of mind. They have built in thermal and current protection so you can wire them direct buss or to a breaker. The first two versions were white. The second version had improved indicator lamp brightness(mine). The latest version comes in any color as long as it’s black This was done probably to improve UV protection because they are rated for outside exposure. The one on the load side (distribution panel) is inside the panel and not exposed.

 

[42OhmsPA]

Can to many be a bad thing?

I currently have Midnites on the grid panel and Inverter AC in panel.
Would there be any reason to add the Schneiders as well?

 

[Steve_S]

Surges, Lightning etc are a constant and in the Solar World this is a longstanding issue with solutions.
YES, You AC Systems should be Surge Protected and new codes in many areas require that regardless now.
The DC Systems also require protection from surges/lightning etc.
Midnite Solar produces / sells some of the best SPD's (Surge Protection Devices) for both AC & DC sides of the fence. While they are not "cheap" as such, they are far cheaper than replacing your kit & your life !
This applies to ALL Products/Brands and not vendor specific.

ENGINEERED FOR BOTH AC & DC ELECTRIC SYSTEMS
MidNite's SPDs protect both transformer and transformer-less inverters without interfering with the GFP protection circuit. MidNite's SPD's provide protection to service panels, load centers or where the SPD is directly connected to the electronic device requiring protection.
OFFERED IN 3 DIFFERENT VOLTAGES - 115, 300 & 600
The MidNite Solar SPD is offered in three different voltages to maximize the required protection level. Protection is achieved by reducing the clamping voltage to a safe voltage that your system can sustain without damaging any electronics in the system.
NOT JUST FOR RENEWABLE ENERGY
Anyone connected to a power grid is suseptible to power surges whether it be a lightning strike or any other cause. 99% of damage to electronic devices is directly related to power surges through power lines. To protect yourself, install MidNite's surge protection near the utility panel.
ENVIRONMENTAL RATING
Type 4X for indoor or outdoor usage.
ROBUST PROTECTION
Four MOV's (Metal oxide varistor) per channel for robust protection. (556,000 Amp Surge Protection Per Channel).
VISUAL INSPECTION
From a distance you can tell if the unit is functioning properly by the LED's that are lit up inside the case! If the MOV's have been hit by a power surge and are all used up, the LED's will go out.
REPAIRABLE
Repairable by a qualified technician.
WARRANTY
5 Year warranty.
SPD CUTIN BOX
Optional flush mounting kit to mount MidNite's SPD's into a wall.
BUILT IN ARLINGTON, WA - USA

Midnite Site Listing for SPD's:

MidNite Solar's Price List

MidNite Solar Price List.

www.midnitesolar.com

Installation Manual: https://www.midnitesolar.com/pdfs/SPD_Installation_Manual.pdf

 

[DIYrich]

Can to many be a bad thing?

I currently have Midnites on the grid panel and Inverter AC in panel.
Would there be any reason to add the Schneiders as well?

From what I understand, no.

Some people put surge protector before the main panel (surge from outside), in the main panel (internal surge), on each line needing protection (last chance to protect sensitive electronics).

 

[Mr onetwo]

I have the Sq D 80KA Spd's on each of my panels and I am going to put one of the midnite Solar 600v units out on my pole at the meter disconnect.

 

[SilverbackMP]

I have the MidNite 600V for each incoming PV line and a 240V version on each panel and sub panel.



Ditek was mentioned up above. I’ll be using their Ethernet surge protector units for POE cameras. All other external coms wire will be fiber.

 

[peakbagger]

I had a Delta on my deceased Fronius Inverter after a utility hit nearby. My neighbor got it the worst but I lost the inverter and a couple of power line carrier devices (X-10). I learned that a Delta might keep the wires in the walls from bursting into flames but that is about it. The inverter was replaced on warrantee (super fast and easy) and a Midnight Solar SPD got installed on the main panel. I also have Midnight Solar SPDs on my roof and pole mount solar at the arrays.

 

[JimP]

If you want really effective surge protection, MOVs are not the way to do it. Look at SurgeX stuff.

 

[Hedges]

Can to many be a bad thing?

MOV have capacitance, so too much downstream of a single phase (L1 only not L1/L2) GFCI could trip it. So long as on both legs, with similar capacitance they will balance each other and not cause ground current. The commercial one I tested tripped HyPot due to ground leakage current at a fraction of line voltage.

I currently have Midnites on the grid panel and Inverter AC in panel.
Would there be any reason to add the Schneiders as well?

A hit will be clamped (somewhat) by MOV. Lowest voltage MOV takes the brunt of it, but voltage will rise high enough to trigger the next as well. Maybe located downstream will allow additional voltage drop due to resistance and inductance.
Having two could mean when one blows (and if it has indicator LED you can tell), the other remains ready to protect during the same storm.

I was thinking DIY with individual MOV. Using LED, making them visible, and preventing contact with live wires represents some design challenge.
Then I found a large commercial unit with 3 phase (120/208) connections and two banks of MOV (different voltages) for the price of a single Midnight so I bought and used that. After testing its breakdown voltage.

Testing Metal-Oxide Varistors (MOV)

Surge arrestors are used on AC and DC side of PV inverters for protection, to clamp high voltage transients. One inverter I have (actually several) are in the SMA family SUNNY BOY 5000-US / 6000-US / 7000-US / 8000-US. These come with a kit of MOV to protect the DC side: The MOVs are about...

diysolarforum.com

I had a Delta on my deceased Fronius Inverter after a utility hit nearby. My neighbor got it the worst but I lost the inverter and a couple of power line carrier devices (X-10). I learned that a Delta might keep the wires in the walls from bursting into flames but that is about it. The inverter was replaced on warrantee (super fast and easy) and a Midnight Solar SPD got installed on the main panel. I also have Midnight Solar SPDs on my roof and pole mount solar at the arrays.

I haven't yet seen the conditions where Delta might trigger. Midnight made a video where it did nothing until hit hard enough to blow apart. (links in my thread.)

Delta LA 602 Lightning Arrestor "Hey! Is this thing on??"

I've been using Delta Lightning Arrestors on my system since they were spec'd by Real Goods as part of the package I bought from them. I now have a surge capacitor on the AC input as well, which is supposed to slow rising edge of voltage so it doesn't get as high before the Silicon Oxide...

diysolarforum.com

 

[spencersm]

I just added a Siemens FS140 to my main panel this last week. Had a surge a few months ago that took out the 24v transformer in our furnace. Christmas morning of all days to wake up to a freezing house... not fun

We have an old washing machine that our 18kPV does not like at all. I wonder if the inverter ramped up and over compensated for the load. But who knows. I do wish there was an easy way to monitor power surges in general. I thought adding a SPD would be good insurance for us as well.

Made a little video walkthrough of the install. Was a lot easier given our unfinished basement so I didn't have to deal with flush mounting it in drywall. I do like the simplicity of the breaker style ones though, I think those make a lot of sense.

 

[Hedges]

I installed the Siemens FSPD in my main panel. Unfortunately, the Sol-ark is between the meter and main panel. Some day I might try to figure out how to wire the Midnight Solar version between the meter and Sol-ark.

That’s an interesting scenario I hadn’t thought of. I’m not aware of a product designed for it off the top of my head, but wouldn’t be shocked if someone made one.

Actually, a surge protector in the downstream panel should provide reasonable protection when grid relay is closed.
When open, only some monitoring and maybe EMI filter parts would be exposed.

So I'd say go ahead and add surge protection to island side now.
Later you can tap off between meter and SolArk to put fuse and surge protection there.