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Electrical surge protection for new boiler?

Does a new boiler, with all it's electronics, need a surge protector and if so what's recommended?

We have a new Burnham system with ODR.


  • Jean-David Beyer
    Jean-David Beyer Member Posts: 2,666
    I would say: most definately.

    I am not a heating contractor, but I used to design electronic equipment back in the days of descrete transistors, diodes, etc., and just into the era of small-scale integrated circuits.

    These days, with all the electronics in modern households, I would say that homes should have a whole-house surge protector in their main power panel, properly wired by a competent electrician. I got a professional electrician to install it so as not to annoy my insurance company or code enforcement officer. It is as easy as installing a circuit breaker. The electrician who did it did not understand the importance of keeping the white wire as short as possible, and someday, I am going to shorten it. Mine is one of these (see pages 7, 8, and 9.:


    Be sure to look at the table on page 9, "Typical Clamping Voltages" to see the amount of protection you can expect. For delicate equipment, you might want to have an additional surge protector right before it. If the U-control on my W-M Ultra 3 is a guide, it has little or no surge protection in it, so you may want to have an additional surge protector as the power enters the boiler. You may also wish to consider putting an unteruptable power supply there that usually as a surge protector in there. I have not done this because the only logical place to put it is in the garage next to the boiler, and the batteries do not like the cold out there. Also, I am not clear how much capacity I need. I mean I can calculate the watts easily enough, but I have no idea how much time I need it to hold up. I have power interruptions of a second or so fairly frequently around here. 10 minutes happen several times a year. Lost power for about 3 days once, fortunately in the summer, when two of the four transformers at the local substation burned out, turning off power to about 4 local towns. I could probably afford a 10 minute UPS, but I guess I would not need that (my radiant slab would not even notice the interruption. but a 12-hour one would be uncomfortable, and I would start to worry about freezing my pipes in the slab after a day or two.
  • SWEI
    SWEI Member Posts: 7,356
    surge protection

    Is only as good is the ground it connects to.  Stopping external influences at the point where the line enters the building is by far the most effective method - just make sure your grounding system is up to snuff (check with a local TV, radio, or wireless engineer if you want to know what is actually needed for local soil conditions.)  Lightning (high frequency energy) does not like to go around corners -- so in addition to short wires, you need to minimize bends and be sure that any bends are kept to 8" or greater radius.
  • Jean-David Beyer
    Jean-David Beyer Member Posts: 2,666
    grounding system is up to snuff

    That is a problem, though.

    I designed recording studio systems in a former life. Grounding is critically important to prevent hum being introduced in the signals. It is very important to keep the white wire and the green wire separate, and never to connect things to the  wrong one. At the very entry to the building, you tie them together (in the main power panel), and ground that at one point only into the ground with the shortest wire possible. Now for audio signals, electrical inspectord do not give a ****, so you can do a good job on this. Now similar considerations are required for surges and lightning (just an extremely big surge).

    But around here the electrical code requires the green wire to be grounded with two separate grounding rods a distance apart. And grouning to a water pipe near where it enters the building is encouraged in addition. So that reduces the effectiveness of using the green wire. It may protect the user of the equipment from shocks when touching the case of the device, but it is no help in hum reduction or surge protection.

    Also, I had a professional electrician put in a new power panel (200 amp instead of 100 amp), and he used the two bus bars (green wire for one and bare or white wire for the other) interchangably, which increases the noise in the green wire a lot.

    Between the electrical code and the lackadasical attitude of the electrician, the grounding in my house is pretty marginal. Oh, and the grounding for the telephone system is on the opposite side of the house, which is lousy too,
  • SWEI
    SWEI Member Posts: 7,356
    edited January 2012
    grounding and bonding

    I spent much of the '80s designing and building television and music production facilities.  I moved on to telecom and data centers in the 90s.  Telecom and broadcast operators have very strict grounding requirements -- I learned a lot from the senior engineers I worked with.

    We did some pretty goofy things in studios to get rid of hum.  Separate ground plates and rods directly underneath mixing boards, star grounding entire rooms, balanced power, you name it.  I have since been educated by a few truly talented circuit designers and have more well-founded opinions about how to solve hum problems.

    First, a few terms from the electrical code (which are frequently mis-used, even by electricians):

    Grounded Current-Carrying Conductor (aka Neutral): The white wire.

    Equipment Grounding Conductor:  The green wire (when downstream of the service entrance.)

    System Bonding Jumper:  The one and only connection between the two above.  On most residential and light commercial services it's actually a screw.

    Grounding Electrode Conductor: The wire that connects the grounding electrode system to the service,  at or very near the Jumper above.

    The reason for "one and only one" connection between the green wire and the white wire is to make sure that the overcurrent devices in the system can trip when a fault to ground is created.  If there exists another bond between them somewhere downstream of the service entrance, fault conditions can be created which will not trip the breakers and start a fire (or worse.)  One of the first tests I do when I get to a new project is to remove the system bonding jumper and put a meter on the ground and the neutral.  If there's conductivity between them, something is dangerously wrong inside the building.

    Your telephone ground is required to be connected to the main electrical ground (look up intersystem bonding jumper.)  Not doing so dramatically increases the risk of lightning-caused damage.
  • Jean-David Beyer
    Jean-David Beyer Member Posts: 2,666
    What you say agrees with my experience.

    What I should do I go through my power service panel and hook all the bare and white wires to one bus bar and all the green ones to the other bus bar. That would be step 1 in an improvement program.

    Another thing to do is put the whole house surge protector at the very top slots of the panel so the ground lead from the TVSS will be as short as possible and as close to the point where the green and white bus bars are connected and where the green wire to two of the ground stakes (about 6 feet apart and over 25 feet from the power panel with  4 right angle bends on their way out. There is also a heavy black wire to the 3/4 inch water pipe that enters the house through a concrete slab. Moving the TVSS is certainly a good idea as it reduces the peak surge that escapes the surge protector.

    Step three would require me to violate the code, as explained by two different electricians. So I do not know what to do about that. That would be to have only one ground stake, and to have it closer to the power panel or meter. Trouble with that is it would require boring through a foot or more of concrete with rocks in it; the footing under the garage slab. One electrician with a helper worked on that for an hour or so, and gave it up. Maybe I could disconnect the big ground wire from the power panel to the water pipe.

    There is yet another ground stake that is part of the bonding and grounding of a piece of CSST. And then there is the ground for the telephone stuff. To hook these all together seems impossible. We would be talking ground wires longer than the entire width of my house, which would seriously reduce the effectiveness of the grounding system.

    If there was an architect to design this house, he gave no thought to grounding and lightning protection. But there was no LWCO or pressure relief valve on my hot water boiler either. I have remedied some of the faults of this house, but there is still a long way to go.
  • SWEI
    SWEI Member Posts: 7,356
    ground rods

    You may have what's referred to as a modified ground ring: two ground rods with 20' of buried bare copper wire connecting them.  That is required here in New Mexico if there's no Ufer (connection to the foundation rebar) present.    

    More ground rods more better -- as long as they're properly installed, spaced, and wired.  Removing bonding connections to other systems (water, gas, etc.) will just make things worse.

    If I were constructing a new building here in lightning country, I'd circle the entire building perimeter with a ground ring, drive and weld a ground rod every 20 feet along it, and possibly add some radials if site conditions warranted.
  • Cliffy
    Cliffy Member Posts: 24
    edited January 2012
    Help understanding this, please.

    I googled "Equipment Grounding Conductor" and it makes it seem the ground wire is supposed to go directly to the appliance (in ths case a boiler) without being connected to anything between the breaker box and the appliance.

    The electrician who wired the new sytem tapped power from a box near the boiler... at that point it it ties into the connection that provides power to a transformer and the circuit is grounded to the box, and that's connected to EMT which goes every which way.  Also, the wire leading to that box originates from another box which I think is just a splice.  The only ground this place has is from a copper wire clamped on either side of the water meter.

    Does that spliced ground defeat the "Equipment Grounding Conductor", ie should the line for the boiler go directly to the breaker panel with no splices or other connections along the way?

    If it neeeds it, is there simply a way of protecting just the boiler with a GFI? 
  • SWEI
    SWEI Member Posts: 7,356

    Includes approved conduit/boxes/connectors.  As long as there is a path back to the subpanel and/or main panel (and it is not connected to the white wire) you are probably OK.

    The validity of using conduit as the EGC have changed over time as new code editions have been adopted, so the specifics of your installation would have to be reviewed along with the code(s) in effect in your local jurisdiction in order to determine whether it is up to snuff or not.

    The water pipe ground was probably code compliant when it was installed.  Whether it is acceptable now would depend on multiple factors.  My biggest concern would be that there is still a continuous metal pipe underground.  It's quite common to have either the building or utility side replaced with polymer pipe, which (while superior for water service) makes a spectacularly bad grounding electrode.
  • Cliffy
    Cliffy Member Posts: 24
    Glad I inquired

    About the water meter ground connection, this house is old enough to have a constricted water pipe feeding in.  The connection passed inspection about a year ago when electrics were ugraded from 60 amps (yes!).

    There's a bunch of inexpensive devices which attach to a double pole breaker and are supposed to provide complete home surge protection.  Looks easy enough to install.  Will get one, likely one of the Eaton CHSPT2 series.

    Thank you.
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