Surge Protection

Unknown

every now and then a lightning storm takes out a bunch of the electronics people have in their heating systems.

Surge protection is a must!

But... what is being used out there? Are most of you seeing that homes are built with surge protection already, or are you adding your own surge protection?

Jean-David Beyer

Surge protection.

This is a very good question. I have a new W-M Ultra 3 boiler and there is no surge protection on it unless it is built into their U-Control board (my guess there isn't).

My computers are all connected to their own Uninterruptable Power Supplies that incorporate serious surge protectors, and they click over to backup battery for a second rather often -- indicating surges or drop-outs.

Since the W-M U-control board is clearly electronic (not just a bunch of relays), I wonder it is resistant to surges, or whether I should have a surge protector installed in there. Or to professionals know they are unnecessary?

Unknown

well, part of what brought this question up was a friend of mine with an Ultra having to replace his control board due to a surge. So I don't think they are immune!

Big Ed_4

Never Enough Protection

I like to wire in boilers with electronics through a line voltage Low Water Cut Off , I rather see the lwco blow before a board in the middle of the night .

Jean-David Beyer

Using LWCO as surge protector.

In a former life, I used to design electronic equipment. I looked inside my LWCO (a McDonnell & Miller RB-122-E) in series between the circuit breaker in my power panel and the boiler. I have little doubt it will do what it is supposed to do, and it might get fried if lightning struck too close to my power line, but I doubt it would protect electronic stuff from 0.1 microsecond power spikes that are quite common. I guess I better see about getting a suitable surge protector for this.

Jean-David Beyer

I just called up APC who make UPS devices for things that must stay up even if the power goes down (I use them for my computers), and also surge protectors. They have a gizmo that goes into the power panel for around $250 that nominally protects the whole house. They call it
Residential Hardwire Surge Suppression
SurgeArrest Panelmount 240/120V 40KA,
that gets wired into the power panel and protects the whole house.

Is this how you guys wire in surge protection? My boiler is hard wired to its own breaker in the power panel. I obviously cannot use the typical plug-in type of surge protector.
Or what do the professionals do?

Empire_2

1 more thought:

Totaline product offers a control called "Linebacker". It acts as a surge or buck protection, but will also give you, Through digital display what actually caused the trip. We use them on A/C for the most part, but can be invaluable for most applications of any kind. Boost and buck voltage problems create the same problems for the most part, but it would be nice to see which is happeneing...:-)

Mike T.

brendan_5

surge protection

look at Brickwall.com you will find some quality protection, I believe the current should pass through rather in parallel this way you will know when/if your protection has been compromised.

hope this helps

Jean-David Beyer

Common mode surges.

I read the Brick Wall stuff, and it seems it would be rather effective for surges, noise, etc., on the hot wire, but if the surge from lightning came along, it seems to me that both the hot wire and the neutral wire will go up about the same. I.e., imagine a 10,000 volt induced voltage from a nearby lightning strike. The neutral wire will be 10,000 volts for a moment and the hot wire will be 10,120 volts. The Brick Wall equipment seems to offer no protection for this at all.

Now if the load is a transformer with, say, 12,000 volt insulation, all could be well, but most transformers are not insulated for anywhere near that much. So the transformer will break down (even though the voltage across its input terminals is within specification) because of the excess 10,000 volts. And even were the transformer insulated for that much, the capacitative coupling, unless the transformer has a substantial electrostatic shield in it (few have any electrostatic shielding), the circuitry on the other side of the transformer will be fried.

So it seems to me that this kind of surge protector could be very effective from the kinds of surges caused by switching heavy loads on and off (provided that adequate low impedance wiring of the neutral and ground wires are in place), but it would not be very effective at dealing with nearby lightning strikes. (For direct hits, I think about the only defense would be adequate insurance.) For nearby lightning stikes, it seems to me one would need some filtering of common mode surges (surges where both the hot and neutral wires go up by about the same amount).

Unknown

Whole house surge protectors

It's not just the sensitive electronics on today's boilers, furnaces and accessories that need protection. Ranges, fridges, microwave ovens, all computer gear and peripherals, TV's and other entertainment stuff need it as well. The plug in "power strip" type are better than nothing, but a whole house unit is what you need. Leviton and SquareD make them, and I'm sure there are others out there. They mount on you service panel, and protect all circuits fron anything but a direct hit lightning strike. They are NOT a DIY project! Get a licensed eletrician to install it. Cheap insurance!

Jean-David Beyer

I agree with Bill Wolfe that it is not just the electronics in boilers and furnaces that need protection. However, this is a heating site and I tried to confine my remarks to that.
My electric stove, for example, has a relay in it that clicks from time-to-time even when the stove is turned off.

I am not in a position to evaluate Leviton and SquareD units because I cannot tell enough, from their web sites, how they function. They seem too small in physical size to contain the parts I would imagine necessary to function correctly. And even were they ideal in some sense, the ground lines, at least in my house, are far too long to get the high frequency spikes to ground. They might save me from being electrocuted were I to touch the case of some piece of equipment, but they will not really get my equipment protected from surges and spikes.

But I do know enough electronics to see that in my house, no matter what you put in the power panel, you will have serious problems.

The biggest problem to me seems to be the electrical code as practiced around here. When I had a new 200 amp power panel installed about 4 years ago, they replaced a relatively thin (12 guage?) ground wire from the power panel to the cold water pipe as it entered the house with a thick black one (around 3/8 inch). They also ran a thick (around 1/4 inch) green wire to a ground stake they installed and it continued to a second ground stake about 6 feet further along. Form a life-safety point of view, this may make sense, but from a noise and surge protection point of view, it is insane. You would want all those redundant groundings as close together as possible and as close to the power panel as possible. Now the water pipe is about 12 feet away from the power panel (a little too far), and the ground stakes are perhaps 30 feet away and in a different direction. So large ground currents will make large ground currents flow through the grounding system, producing large common mode noise including spikes and surges.

Jamie Hall

The trick

to the whole house surge protectors is that they electronically crowbar all the lines -- both hots, the neutral, and the ground -- together. So, in principle, everything moves together and, again in principle, you shouldn't have a problem.

In practice, now... So much depends on the waveform of the spike, and its amplitude, and the exact routing of the wires from point x to point fry. They're a good bit better than nothing, though -- although after a direct it on a line, you may have to replace them.

A surge protector is NOT a UPS, although most UPS units (like APC's) have surge protection built into them. And a whole house surge protector won't do a thing for 'dirty' power, sags, low volage spikes (say double nominal) and other sundry electrical gremlins!

Big Ed_4

Seems to me ....

... Being struct by lightning and all we do to protect , it's still a crap shoot , you can not control nature , everything we try to do just helps to better the odds. Like eveything in life ... Atleast we know how to replace the fried equitment when and if it happens. Maybe make a few dollars at it

Jean-David Beyer

Jamie is right about most surge protectors. The Brick Wall ones are different. They amount to a clever low pass filter between the hot wire and the neutral. Such filters can be effective for problems on the hot wire, provided the device is well made with carefully designed components. For example, the inductor should not allow much capacitative leakage across it. And I suppose for typical "whole house" protection, you would need two of these devices (if they are as shown on the web site), one for each "phase" of the 220 volt system. The designer seems proud of the fact that his devices put no current into the ground wire, which is polite. Unfortunately, such devices do NOTHING to reduce common mode problems.

The rest of the whole house surge protectors seem to use metal oxide varistors to shunt the surges and spikes into the ground wire. There seem to be two problems with these.

1.) Large surges can damage the MOVs and leave you without protection. Some of these devices provide an LED to warn you about this.

2.) If my house is typical, the ground wire(s) is (are) way too long to get really good results. For example, a Square D QO2175SP protector gives its ratings based on various lengths of the ground connection. For a 1500 Amp surge, if the ground wire is between 1 and 6 inches long, the clamping voltage will be about 475 volts. For 12 inches and 18 inches, it is 500 volts. Now they are talking about the distance between the protector in the power panel and the bus bar also in the panel near the main circuit breaker. But of course, it is important to consider how long the wire from the panel to the real ground is. In my case, it is about 144 inches to the water pipe as it enters the house, and the other one or two (depends on how you count them) are closer to 30 feet away. The impedance of the ground circuit makes everything worse.

But as you say, almost any surge protector is better than none, and that one is designed for my power panel, so it should not cost as much as the Weil McLain U-control board to have it installed. I would like it in there before the August thunderstorm season starts around here.

KevinCorr

hurry

I better get with it quick. My EK System 2000 manager is 25 years old. I better hurry before I put in a new boiler