Print

[K0ZN]

This may not be the "proper" location for this question, but I know there are a lot of technically competent people on here so......

Does a " whole house" surge protector have a recommended service life?  What about the smaller "residential" type surge protectors. Should those be replaced periodically? I am not aware of an easy way to test such devices without some lab quality test equipment.
Do MOV's degrade over time? I'm sure surge protector manufacturers declare a service life, but their views are probably a bit biased.
Lightning season is just around the corner, so time to look into this.

Comments appreciated.  Thanks.  73,  K0ZN

[KL7JT]

Your question reminded me to look at mine; thanks. We had an overvolt from our utility here in the wilderness, 20 miles West of Boston, which fried a couple of the usual outlet strips with "surge protectors". I don't know status of our "whole house" protector at the main panel as it has no indicators and need to check it.

MOVs fail in various ways, catastrophically if they absorb enough energy, and can change characteristics more slowly if they conduct during low energy events. I have seen the former and been told of the latter by other engineers, but have never measured. Your comments re testing are correct, I think, because simple go, no-go testing doesn't always tell the whole story.

I just looked at what was available from the usual sources. I notice that with Eaton, you get some warranty and secondary "insurance" on connected devices. More you pay, greater the "coverage" and length of time it is in force. I have no relation to this company. I suspect that it's good if it works, and takes effort to invoke the warranty coverage, should you need it. Direct lightning strikes are an exclusion; it's tough to clamp 200kA.

That said, there appear to be "status indicators" on the front of some which might answer your question.

Hopefully, some licensed electricians who have experience with these will comment.

73

[SWMAN]

 I have an Eaton whole house surge protector on my main panel in my home. It has 2 green LEDs on it that are always lit. Just under the LEDs is printed,” Full Protection when both are lit.” The booklet does not really explain anything. So I guess if one or both of the LEDs are out then the unit should be replaced. If the unit takes a lit, maybe it will blow the LEDs. Not really sure. Nothing is really explained very well. But at least for now both LEDs are lit for about 3 years now.

[KB2DUL]

I just recently had my Amplifier severly damaged by a massive Surge in the AC. Power. It only blinked for about 2 seconds but when it returned it created the surge. I just installed a Square D brand 80KA whole house surge protector. Installation is very easy. In the event of a massive surge the surge protect will self destruct to save the equipment. the light on the unit will go out when this happens. There is no age limit on these devices

[K0ZN]

Thanks for the replies. Much appreciated.
One of the things that triggered this inquiry is that I also have a "whole house" surge protector made by DiTek recommended by an electrician friend. I installed it about 6 years ago. It also has two green LED's and the "Protected if both lights lit." Message. The issue here is that one LED is about 75% as bright at the other one.... Yes, it is "lit" but not quite full brightness. Is that an LED problem or has it taken a hit??  We get a lot of heavy lightning around here in spring and summer severe weather season, so I am trying to get ahead of the curve.
Agree: if you get a direct hit on your house, it is game over. I have a lightning rod system with extensive earth grounding on the house which I hope improves my odds. Time will tell.

73,  K0ZN

[AA4PB]

My surge protector is the size of a double pole breaker and fits into the #1 spot in the electrical panel. It has two green lights on it. If it takes a large enough surge, the internal TVS diode will fail shorted which blows the internal, non-replaceable fuse to protect the panel from the short circuit. That means no power to the LEDs so they go out as an indication that the device needs to be replaced.

[VE7RF]

At the Telco I worked at for 34 years we used Joslyn brand (made in the USA) surge protection.  They used field replaceable huge MOV's..and also field replaceable large style cartridge fuses.

Each MOV is fused with the  fuse inside the MOV box assy...which resides just below the main panel.  At the output of each fuse, it feeds 120 vac into the input of the MOV....and also to the input of a NEON...and also the input relay coil of a 4PDT relay.  At main panel end, they use  a 2 x pole breaker (single phase)...or a 3 x pole breaker (3 phase).

The relay is energized 24/7.   When MOV's fail, they always fail..shorted.  When the MOV shorts, the fuse blows open, and the NEON goes out  (no longer illuminated).   The relay coil no longer has any 120 vac, and it drops out.  When the relay drops out, it puts a ground onto the alarm lead..... which  brings in an alarm  at the main alarm monitoring NOC. 
(network operations center).

For small sites, like cell sites, that run on 240/120 vac.... only 2 x MOV's used, only 2 x NEONS....and only 2 x 4PDT relays.  In main central offices,  which use 208/120 vac  3 phase power,  3 x mov's used, 3 NEONS..and 3 x 4PDT relays.
MOV's are always wired hot to neutral..... ditto with NEONS and relay coils.

We have thousands of these  Joslyn  lightning protectors  in use. Never lost any equipment from surges, spikes, hiccups, transients etc...not during my tenure.

The newer versions use LED's  instead of Neon's.  Other than that, zero difference.

Always installed at the main panel.   Neutral and grnd are bonded together  in the main panel.  Typ external ground  setup
consisted of 10'/20' copper ground rods,  every 10'/20'  around the perimeter of the building, and all CAD welded  below ground, all wiring also below ground level. (none of it is visible).

The whole house protection devices appear to be similar, minus the alarm relay.  I'm told that in some parts of Florida, insurance companies will mandate their use.   In some cases, the entire MOV assy is external...next to the power meter, so the power company can see that one / both LEDS are out....and the power company can field replace the shorted MOV(S) and mating cartridge fuses. 

I would recommend  the whole house protection scheme for residential use.  Their service life is indefinite.   They just sit there...till something bad happens.  Cheap insurance, vs  blowing up stuff in your home..and hassling with insurance companies. (did the fridge just crap out, or did a transient / surge take out the fridge, prove it, pretty tough to prove).

[K0ZN]

 VE7RF:  Thanks. That was the kind of info I was looking for. Appreciate it.

  73,  K0ZN

[KC3TEC]

Of the ones I installed most were equipped with a single led.
If it was dim, out completely,  or flickering it had taken a large surge and was recommended to replace them.

Whole house surge protection is the same as regular oil changes in your car.
While individually expensive, they are still damn cheap insurance.

Monitoring the quality of your electrical service is very sketchy due to the constant variety of loads and conditions of the line gear.
A line power conditioner is expensive but is the absolute best for protection of your gear against both high and low power fluctuations including mass surges ( shy of completely isolation from line power)
(Battery operation only)

We spend a lot for our equipment so it's justified to go to the best protection for our investment.

[KD6VXI]

Where I'm at, surges are a way of life.  Especially if you are connected to the local utilities.

At work we aren't.  I have multiple megawatts of power production here with surge protection on the 25kv incoming, 13 kv distribution and at the 480 volt level.

Even with this, we still put them on all panels.   And we aren't connected to the utility for almost 360 days out of 365.  We only connect to the utility when we need to take all generators down for service, service the MV or HV, etc.

My house also has an Eaton surge protector on it.

Just a good idea when you live where I do.

--Shane
WP2ASS / ex KD6VXI

[VR2AX]

Grid problem? Energy conversion is not linear (asymmetry). Does your local provider have (enforceable) service standards? Usually it's a question of mass energy behind the supply. VR2/VK6 ran on 220 nominal, it required the cross border backup.