boiler

msl50birm

We had a boiler installed to heat our garage going on 2 years. We also live in an area with frequent electrical outages. I installed a whole house surge protector. Nonetheless, our boiler, Weir McLain, has needed two boards to be replaced. How can I protect this boiler without having to install a back up generator? Thanks for your suggestions.

BobC

Surge protector

Is this garage attached to the house or a a separate outbuilding? If it is attached installing a whole house surge protector should fix any problems with surge damage. If it's a separate building it depends on how the wiring gets to the outbuilding and if the damage is being caused by close lightning strikes.



Bob

Jim Godbout

Voltage regulator

Voltage regulator directly connected to unit vs surge protector will give you much more protection.

Surge protectors are very limited in what they can do.

HomeOwner1

Computer backup battery system is an option

Staples or any office supply store will have them. An inexpensive APC or other brand backup battery UPC will do a few things. It will clean the power, provide surge protection, protect against brown outs and provide a short battery backup window.



Some of them even allow you to log to power conditions, graph and log power issues. You can maybe use this to submit to your utilities commission in your state to get the power company to ultimately fix your issue to avoid the hassle going forward.



There are different ratings on them. Just make sure you get one with enough capacity for your power demands. In this case, bigger is typically better.



Good luck.

Jean-David Beyer

make sure you get one with enough capacity for your power demands.

This may be a problem for most users.

My boiler has an electronic control board, a blower for the combustion air that also forces the combustion byproducts away. It has four Taco 007 circulators, and three of them could run at the same time.



Last year, the power was out here for 6 1/2 days. It would have taken a pretty big backup power supply to handle that.



I have a whole house surge protector in my power panel. I use APC Smart-UPS units for my computers, and one for my FiOS communications (telephone and Internet). But things like this would never manage my boiler, much less my refrigerator, electric stove, etc. I did endure that for a week, and this year, I had a Kohler natural gas powered backup generator installed. This kicks in 7 seconds after the power companty fails me. A month or so ago, it did that for a little over 1/2 hour, and the backup generator worked just fine. My heating system was powered on, but I do not recall if it was actually trying to heat the house or not at that time.

Jean-David Beyer

make sure you get one with enough capacity for your power demands.

[once was enough]

icesailor

Surge Protection:

Explain to me how I am wrong.

Studies of lightning through time lapse photography have shown that in a sense, there are two lightning strikes. One from the cloud to the ground, and a back strike, of returning electricity. There may be one main strike but many returning spikes. There was a series years ago in National Geographic Magazine about Lightning and there was a photo if an oak tree in a field with a large down strike hitting the tree and all around the tree were these little 1' electrical spikes coming out of the ground. To go back to the cloud. I have personally seen damage in houses that could ONLY have been caused by "Back Strikes. Like holes blown through 4: PVC well casings that came from the OUTSIDE to get at the electrical cables and blew up the Surge Protector.

A "Surge Protector" is like a little electrical check valve on the supply or hot side. There are no such protections on the neutral and ground/earth side. I contend that, because of all the electronic boards I have seen, destroyed after electrical storms, that unless the whole appliance is burned black, returning electrical voltage comes back through the house grounding system. Which consists of a driven "Earth Ground" and other possible earth grounds.

If you connect a battery to a car with an alternator and the polarity is reversed, you will blow the diodes in the Alternator because of reverse flow. The Diodes are just little electrical check valves.

If my supposition is incorrect, I'm open to have my mind changed.

SWEI

Surge Protection

The vast majority of surge protectors are based on Metal Oxide Varistors, aka MOVs.  http://en.wikipedia.org/wiki/Varistor  The closest plumbing analog would probably be a PRV.  When the line voltage exceeds the clamping voltage of the MOV, it conducts, lowering the voltage by shunting the current to ground.  The quality of the ground is critical to their operation, so applying them at the service entry (where the ground is) generally works best.



Less common are avalanche diodes and gas-discharge tubes.  They have characteristics which complement those of MOVs.  More sophisticated (read that expensive) protectors frequently combine more than one type of device.

Steamfitter66

Back up generator wont help

An isolation transformer will.

Jean-David Beyer

Back up generator wont help

"An isolation transformer will."



The only thing a backup generator will do is restore the power pretty soon after the power company lets you down. This will help your system stay up longer than the 5 or 10 minutes it might keep a typical computer running. I have a UPS that might keep my boiler running for a half hour if the batteries were new, or about half that when they are about 3 years old.



But what good would an isolation transformer do to protect the control board in a boiler? It might help very slightly if the isolation transformer has an isolation shield (heavy copper foil, grounded, between the primary and secondary) but few of them do.



More likely, a serious surge protector just before the boiler would be needed in addition to a whole house surge protector. I notice my (Square D) surge protector will keep the spikes and surges down to about 1000 volts which is a big improvement. But unless the control board is designed to tolerate that kind of thing, you will want a smaller, but more effective one right before the boiler control board. Actually, they should be designed in in the first place.



And none of this does any good unless the grounding system for the house is top notch, and the electricians around where I live do not understand this stuff at all. And neither do the electrical inspectors. The inspectors are not stupid, but they are concerned only with saving your life, so they want multiple ground wires to multiple ground stakes distributed over an area. But for surge protection, you want only a single ground, a very short distance from the main distribution panel, and everything grounded through that. And the white wires and the green wires should go to separate bus bars, and the two bus bars should be connected together at only one point and that point should be only a very short distance from the ground stake. But the electricians connect the green and white wires haphazardly to which ever bus bar is easiest for them, and this allows common mode noise to be a problem.



Oh well.

HomeOwner1

Clean Power is the key

If you want to clean the power, then a good UPS will do that. You will need to calculate the max power load and size accordingly.



It will also protect against brown outs (partial losses of power) at a minimum, and a short power outage.



It will also provide surge protection.



If you have those concerns, this is the best route to go.



If you want long power outage protection times, then you can add a backup generator as well. A UPS is still not a bad thing to have even then to clean the power.



Good luck and hope this helps.

BobC

isolation transformer

will protect you from common mode faults and if it's a big one with lots of iron it can help clean up the waveform. A good isolation transformer with a properly installed whole house surge protector will do a good job of protecting you from a surge; adding a local surge protector at the control board would improve the protection. It should protect for hot to neutral AND neutral to ground.



We used to design these systems into military electronics that see terrible power surges.



Nothing on earth will protect you from a lightning strike, if you think your getting strikes near the house I'd suggest a lightning arrestor system be installed by someone qualified.



A good UPS will work on surges but a good one will cost you more than new flat panel TV and it won't run a system with motors if the power goes out for any real amount of time. We used to use the 1KW APC rack mount units, they are very good but not cheap.



If you use a generator it should have a sine wave output and the frequency has to be set at a stable 60 HZ. Some misguided designers build watchdog protection into heating controllers that they don't need and that is why some systems have trouble running on anything but stable 60 HZ sinewave power; the electronics itself does not care as long as good practices were followed when designing the power supplies on these controllers..



Bob