Steam during power outage

ethicalpaul

I was thinking about power outages and steam heat. Our steam systems (well at least natural gas...not sure about oil) require ALMOST no power at all to provide beautiful heat during a power outage. But there's no easy way to get temporary power to the controls to benefit from this huge huge advantage.

Does anyone wire their system using a plug, or a switchover to a small generator that could easily provide the power to run the controls? It can't be more than 100 watts to drive the gas valve, auto-damper, etc.

I suppose code would frown on a plug haha

ethicalpaul

Google is always good I guess

http://www.lmgtfy.com/?q=heatinghelp.com+boiler+power+outage

Jamie Hall

Some natural gas/LP systems require no power at all -- the older natural draught with a thermopile type gas valve!

Newer systems do require power, and some -- with induced draught power burners, and oil systems, actually require a moderate amount of power. If that's the only load, though, it would be quite possible to run them for quite some time with a good inverter (modern electronics require very clean power) from a battery bank. And I'm sure that there are a number of people who do -- often with the battery bank floating off the mains in a standard UPS configuration.

Others -- such as the various places I care for -- have generators for part or full household loads. Sometimes automatic switch over, sometimes manual.

All that said. If you plan to do this sort of thing, do it to code. The electrical code is not there to annoy you, but to save property (yours) and lives (yours, and your neighbours and the linemen who are trying to reconnect you). A boiler, as a fixed appliance, must be hard wired and properly grounded, with suitably sized circuit protection. Plugs won't do it. Any generator or UPS type system must be equipped and wired in such a way that it cannot back feed into the mains (a UPS is designed and built to do that; a homebrew might not be). A generator must be connected through a break before make transfer switch designed and listed for the purpose.

Please don't cut corners on this -- even if Joe Sixpack, just down the street, has been doing it for years and even has a YouTube video.

ethicalpaul

I won't cut corners, but I do find it interesting that a plug, although perhaps not up to code, would provide an extremely safe backfeed prevention.

Jamie Hall

The reason plugs are discouraged is that they can be -- and not infrequently are -- wired backwards, so hot and neutral are switched. And sometimes the ground is iffish, at best.

ethicalpaul

Jamie Hall said:

The reason plugs are discouraged is that they can be -- and not infrequently are -- wired backwards, so hot and neutral are switched. And sometimes the ground is iffish, at best.

Yeah, and that never happens with hard-wired connections

Jamie Hall

ethicalpaul said:

Jamie Hall said:

The reason plugs are discouraged is that they can be -- and not infrequently are -- wired backwards, so hot and neutral are switched. And sometimes the ground is iffish, at best.

Yeah, and that never happens with hard-wired connections

yeah, well.... sigh...

ChrisJ

I've yet to see an HVAC appliance that cared which was hot and which was neutral.

That said,
@ethicalpaul I had considered using a large UPS to power my boiler. Something like 1000-1500VA because it would last a good amount of time running just a steam boiler. You would of course need a plug which is what kept stopping me from doing it. I just don't like the idea. It's against code, and with my luck someone would unplug it to plug in a crockpot or something.


Since that idea I've ended up with two generators which I can use to power the entire house.

Gsmith

I think @jamiehall's suggestion of a dedicated UPS would pay looking into. It has a plug and could be plugged into a very small generator to periodically recharge if needed.

ethicalpaul

Thanks guys! I think I'll look at a small generator on select circuits in my future new panel.

NY_Rob

^ one of the modern/small "inverter generators" would be your best bet, especially if you have any ECM pumps. ECM pumps really need a nicely formed sine wave to prevent damage.

ratio

Most/all modern furnaces are sensitive to polarity. It interferes with the flame sense I think, so anything with a modern electronic ignition board will suffer from it as well. Some (But not all, &ltsigh>) control boards have a reverse polarity fault code.

But yah, a standing pilot system? Be fine. Better yet, a millivolt steamer. I think that'd be my 'perfect system'.

FriendlyFred

One night last year, around Christmastime, the temperatures were in the negative range and we had a bundle of guests over when the power went out for the surrounding neighborhood.

Ever aware of heat-loss, I robbed items from vehicles in the garage and went down to the gas-fired steamer in the basement. Here's how it went down:

1) The boiler and controls are the only connections on its circuit breaker, so I shut off the power.
2) Use wire nuts to replace the power feed lines to a length of lamp cord with standard male plug.
3) Connect a 12vdc->120vac power inverter to car battery.
4) Then, plug in the hacked lamp cord. Voila.

I measured a draw of 13 watts while the burner was firing, which
meant the car battery would last long through the night. The next morning, everything was returned to normal, and that power inverter now lives in the rafters above the boiler.

Sub-zero temperatures, 'field-expedient' repairs, and warm happy guests. That right there is the stuff dreams are made of.

JUGHNE

But would you still have cord/plug on the appliance plugged into the UPS which is plugged in to the wall outlet?

I feel a "correctly" installed 3 wire cord and simple outlet is a much safer setup than someone trying to cobble around in the dark with a generator and possibly back feeding the system.

The cord installer must understand the difference between the "grounded" and the "grounding" conductors.
If that is challenging then that person should not attempt such a venture. IMO
Yes, code violation.....but like Jaywalking..... if you take precautions it can be a safe experience.

ChrisJ

ratio said:

Most/all modern furnaces are sensitive to polarity. It interferes with the flame sense I think, so anything with a modern electronic ignition board will suffer from it as well. Some (But not all, &ltsigh>) control boards have a reverse polarity fault code.

But yah, a standing pilot system? Be fine. Better yet, a millivolt steamer. I think that'd be my 'perfect system'.

My spark ignition is driven by a transformer which just has two black wires on the primary. Pretty sure my air handler with ECM motor was the same deal as well.

That doesn't mean others aren't, but the ones I've dealt with didn't care.

I am confused as to how you reverse polarity on an AC circuit though @ratio ?

ratio

Hot & neutral reversed. Some things don't care, some things do. Mostly new stuff. Like I said, many of the new gas furnaces I install are sensitive to reversal of the grounded & ungrounded phase (I suppose that's the correct technical term) & will not light & possibly flash a fault code. Some modern fluorescent ballasts don't care to operate backwards either IIRC.

ChrisJ

ratio said:

Hot & neutral reversed. Some things don't care, some things do. Mostly new stuff. Like I said, many of the new gas furnaces I install are sensitive to reversal of the grounded & ungrounded phase (I suppose that's the correct technical term) & will not light & possibly flash a fault code. Some modern fluorescent ballasts don't care to operate backwards either IIRC.

Have you noticed any SMPS in modern furnaces or are they still using a normal transformer?

ratio

Hmmm. I'll have to take a look the next time I've got one open. The majority of it (safeties, gas valve, etc.), runs on 24VAC via an xfrmr, but I'm sure the µC doesn't; some higher end systems are actually communicating between the stat, air handler/furnace, & heat pump/condenser now (RS485 or some bastardized variant). I'm not sure I'd recognize a switcher verses a linear PS without looking up the part numbers.

ChrisJ

ratio said:

Hmmm. I'll have to take a look the next time I've got one open. The majority of it (safeties, gas valve, etc.), runs on 24VAC via an xfrmr, but I'm sure the µC doesn't; some higher end systems are actually communicating between the stat, air handler/furnace, & heat pump/condenser now (RS485 or some bastardized variant). I'm not sure I'd recognize a switcher verses a linear PS without looking up the part numbers.

I'm by no means an expert,and I don't think I could explain it but I can usually tell by looking at it.

https://en.wikipedia.org/wiki/Switched-mode_power_supply

Dan_NJ

I have a pretty simple setup for my steam boiler which is an 120v inlet placed between the panel and the boiler with a three way switch between inlet and panel - line/off/inlet. I keep at least one AGM group 35 battery on float at all times (same size my vehicle uses, extra handy) and have a sine wave inverter to hookup to that. If an outage goes more than a day I might get out the generator, but I prefer silent battery power

ethicalpaul

> @ratio said:
> Most/all modern furnaces are sensitive to polarity. It interferes with the flame sense I think, so anything with a modern electronic ignition board will suffer from it as well. Some (But not all, &ltsigh>) control boards have a reverse polarity fault code.
>
> But yah, a standing pilot system? Be fine. Better yet, a millivolt steamer. I think that'd be my 'perfect system'.

I’m pretty sure my 24v transformer doesn’t know or care which side is hot but I’ll wire it correctly anyway 😅

JUGHNE

Most 24 volt transformers have a side of the secondary grounded to the chassis. This is the reference ground for the flame rectification system to work.
All 120/24 transformers would have one side of the primary, (white-neutral) grounded. The white neutral (grounded) and the bare/green (grounding) would be bonded together only at the service disconnect of the building. They should never be connected together after that point.

I believe the concern of reversed polarity on the 120 primary is because it has one leg grounded as does the secondary side.
IDK how to explain it but, somehow the lead/lag of transformers comes in play.
Important enough for the board designers to throw in an addition trouble code to ID reversed 120v polarity.

jumper

Jamie Hall said:

The reason plugs are discouraged is that they can be -- and not infrequently are -- wired backwards, so hot and neutral are switched. And sometimes the ground is iffish, at best.

Wondering about the why for almost half a century. CanadianGasAssociation outlawed plugs and insisted on wall switch to kill furnace. In US I saw plug for furnace and that struck me as more sensible. Panicked people can mistake which position is off. Switch can fuse closed maybe.

I also agree with iffish. Strictly speaking what we call neutral is return. Third prong if there is one is hopefully neutral. And ground is for the box. How often do we see that even in hospitals,labs, or ships?

ratio

Ground prong is 'equipment grounding conductor'. Neutral is 'grounded phase'. In the past, swapping hot & neutral could result in chassis/exposed metal being at line voltage potential, but I think the lawyers have pretty much solved that problem.

ISTR that the problem modern ignition boards have with revered polarity is that the flame rectification doesn't work. Makes sense if the flame rod operates at roughly line voltage, as I've heard on the internets to be the case. IDK that much about it. But I do know that if you wire a furnace & it inexplicably doesn't work, you check the polarity of the incoming power.

SeanBeans

Lennox furnaces will show am error code if your polarities are reverse

mikeg2015

I measured my boiler and even with a fresh air damper and draft damper and its large gas valve, was only 42 watts. I have a power inverter I could hook my car battery. Polarity should be correct. Would need to hard wire it however Don’t have a manual transfer switch on it.

PMJ

Just pay for a generator and proper transfer switch breaker panel. Worth every penny when you need it.

ChrisJ

> @PMJ said:
> Just pay for a generator and proper transfer switch breaker panel. Worth every penny when you need it.

Most cannot afford such things @PMJ .

PMJ

> @ChrisJ said:
> > @PMJ said:
> > Just pay for a generator and proper transfer switch breaker panel. Worth every penny when you need it.
>
> Most cannot afford such things @PMJ .

Ok so this is not an all or nothing kind of deal. There are many possible levels to this at a wide range of costs. I would say the key things are safety and ease of use so the backup power is easily available and anyone can do it.

Running a steam boiler and a refrigerator to have heat and not lose food summer or winter would be a place to start. A very small portable generator can do this. The important thing is a proper panel which makes it impossible to connect the generator to the line coming into the house. This is the only way to be fool proof and safe. The switch panel to do this on a 60Amp service costs about $90. It goes between the meter and the first breaker panel. There is the cost of the electrician, but this is not a complicated installation.

The good news is that once the panel is in, you can connect any size portable generator you want from emergency only bare minimum to whole house. You pick and choose what you will run with your own breakers. I have a 16HP 7000KW portable gasoline generator and a 200A Reliance TTV2003C panel. Put it in 23 years ago. Need it maybe 2 times a year. I put simple instructions right on the panel and my wife has done it a couple times.

If power outages are a concern at all I highly recommend this setup at a minimum level. A few hundred $$ well worth it. One time shot. Nothing used enough to wear out.

ChrisJ

PMJ said:

> @ChrisJ said:

> > @PMJ said:

> > Just pay for a generator and proper transfer switch breaker panel. Worth every penny when you need it.

>

> Most cannot afford such things @PMJ .



Ok so this is not an all or nothing kind of deal. There are many possible levels to this at a wide range of costs. I would say the key things are safety and ease of use so the backup power is easily available and anyone can do it.



Running a steam boiler and a refrigerator to have heat and not lose food summer or winter would be a place to start. A very small portable generator can do this. The important thing is a proper panel which makes it impossible to connect the generator to the line coming into the house. This is the only way to be fool proof and safe. The switch panel to do this on a 60Amp service costs about $90. It goes between the meter and the first breaker panel. There is the cost of the electrician, but this is not a complicated installation.



The good news is that once the panel is in, you can connect any size portable generator you want from emergency only bare minimum to whole house. You pick and choose what you will run with your own breakers. I have a 16HP 7000KW portable gasoline generator and a 200A Reliance TTV2003C panel. Put it in 23 years ago. Need it maybe 2 times a year. I put simple instructions right on the panel and my wife has done it a couple times.



If power outages are a concern at all I highly recommend this setup at a minimum level. A few hundred $$ well worth it. One time shot. Nothing used enough to wear out.

If their panel supports it an interlock is a very affordable and safe option. Much more affordable than a transfer switch.

PMJ

ChrisJ said:

PMJ said:

> @ChrisJ said:

> > @PMJ said:

> > Just pay for a generator and proper transfer switch breaker panel. Worth every penny when you need it.

>

> Most cannot afford such things @PMJ .



Ok so this is not an all or nothing kind of deal. There are many possible levels to this at a wide range of costs. I would say the key things are safety and ease of use so the backup power is easily available and anyone can do it.



Running a steam boiler and a refrigerator to have heat and not lose food summer or winter would be a place to start. A very small portable generator can do this. The important thing is a proper panel which makes it impossible to connect the generator to the line coming into the house. This is the only way to be fool proof and safe. The switch panel to do this on a 60Amp service costs about $90. It goes between the meter and the first breaker panel. There is the cost of the electrician, but this is not a complicated installation.



The good news is that once the panel is in, you can connect any size portable generator you want from emergency only bare minimum to whole house. You pick and choose what you will run with your own breakers. I have a 16HP 7000KW portable gasoline generator and a 200A Reliance TTV2003C panel. Put it in 23 years ago. Need it maybe 2 times a year. I put simple instructions right on the panel and my wife has done it a couple times.



If power outages are a concern at all I highly recommend this setup at a minimum level. A few hundred $$ well worth it. One time shot. Nothing used enough to wear out.

If their panel supports it an interlock is a very affordable and safe option. Much more affordable than a transfer switch.

Reliance has many options. Maybe you associate transfer switch to something that is automatic when the power goes out which is expensive. To me it just means this: https://www.lowes.com/pd/Reliance-Panel-Link-7500-Watt-Generator-Transfer-Switch-Kit/4729211

ChrisJ

PMJ said:

ChrisJ said:

PMJ said:

> @ChrisJ said:

> > @PMJ said:

> > Just pay for a generator and proper transfer switch breaker panel. Worth every penny when you need it.

>

> Most cannot afford such things @PMJ .



Ok so this is not an all or nothing kind of deal. There are many possible levels to this at a wide range of costs. I would say the key things are safety and ease of use so the backup power is easily available and anyone can do it.



Running a steam boiler and a refrigerator to have heat and not lose food summer or winter would be a place to start. A very small portable generator can do this. The important thing is a proper panel which makes it impossible to connect the generator to the line coming into the house. This is the only way to be fool proof and safe. The switch panel to do this on a 60Amp service costs about $90. It goes between the meter and the first breaker panel. There is the cost of the electrician, but this is not a complicated installation.



The good news is that once the panel is in, you can connect any size portable generator you want from emergency only bare minimum to whole house. You pick and choose what you will run with your own breakers. I have a 16HP 7000KW portable gasoline generator and a 200A Reliance TTV2003C panel. Put it in 23 years ago. Need it maybe 2 times a year. I put simple instructions right on the panel and my wife has done it a couple times.



If power outages are a concern at all I highly recommend this setup at a minimum level. A few hundred $$ well worth it. One time shot. Nothing used enough to wear out.

If their panel supports it an interlock is a very affordable and safe option. Much more affordable than a transfer switch.

Reliance has many options. Maybe you associate transfer switch to something that is automatic when the power goes out which is expensive. To me it just means this: https://www.lowes.com/pd/Reliance-Panel-Link-7500-Watt-Generator-Transfer-Switch-Kit/4729211

I guess some still have 60A service but not too many.

PMJ

Check out the catalog. Many options at all service levels. That was just an easy example.

http://www.reliancecontrols.com/

ChrisJ

@PMJ This is what I use.> @PMJ said:
> Check out the catalog. Many options at all service levels. That was just an easy example.
>
> http://www.reliancecontrols.com/

What is the benefit of that style over an interlock?
Both are manual, both switch the entire panel, no?

PMJ

I think if you want to keep your existing breaker panel you can go with the simple one in between. I changed my whole panel because I upgraded to 200A service at the same time.

NY_Rob

ChrisJ said:

If their panel supports it an interlock is a very affordable and safe option.

It also keeps everything in one panel vs another "box" hanging from your basement wall.

Only minor drawback to the interlock device is that it generally needs to be installed in the top two righthand breaker slots... so if they are already occupied (by existing breakers) you have to relocate those breakers... and some may be on short wires so you have to do a Tetris thing and move other breakers around till everything fits back in again with no tight wires. It just takes a little pre-planning.

Leonard

Moving breakers.......
if have a share neutral circuit MUST be very carefull to move breakers to same phase of panel buss as they were on. Other wise currents in the neutral could add instead of cancel and you could overheat the neutral and start a fire in house wiring


Interlock....
I plan on using an interlock with my gen that I bought and fixed for the sole original purpose of powering my oil furnace. Believe New Jersey does not allow them, only plug and cord or transfer switch.

Direct Bat powered ....
If your vapor fuel steam furnace has "simple" controls ( standing pilot and gas solenoid) might be able to replace transformer with a battery.

When I experimented with my central vacuum cleaner's power relay ( 24 VAC coil) I measured AC current to coil , and coil's DC resistance. I found inductance's portion of total impedance to be ~ 5X it's DC resistance. So if I powered relay with ~ 6x less voltage it's amps might be ~ same and it might work.

Word of warning though, believe AC relay coils are designed differently than DC coils. Something about when relay is pulled in the inductance increases and that reduces current ( so doesn't run as hot). OF course possible that bat voltage might have to be different for every relay or solenoid in there.

ChrisJ

> @Leonard said:
> Moving breakers.......
> if have a share neutral circuit MUST be very carefull to move breakers to same phase of panel buss as they were on. Other wise currents in the neutral could add instead of cancel and you could overheat the neutral and start a fire in house wiring
>
>
> Interlock....
> I plan on using an interlock with my gen that I bought and fixed for the sole original purpose of powering my oil furnace. Believe New Jersey does not allow them, only plug and cord or transfer switch.
>
> Direct Bat powered ....
> If your vapor fuel steam furnace has "simple" controls ( standing pilot and gas solenoid) might be able to replace transformer with a battery.
>
> When I experimented with my central vacuum cleaner's power relay ( 24 VAC coil) I measured AC current to coil , and coil's DC resistance. I found inductance's portion of total impedance to be ~ 5X it's DC resistance. So if I powered relay with ~ 6x less voltage it's amps might be ~ same and it might work.
>
> Word of warning though, believe AC relay coils are designed differently than DC coils. Something about when relay is pulled in the inductance increases and that reduces current ( so doesn't run as hot). OF course possible that bat voltage might have to be different for every relay or solenoid in there.

Please tell me where you found something suggesting approved and properly installed interlock kits are not allowed in New Jersey.

Also, never tell someone to try and power a gas valve with DC if it's rated for AC.

Leonard

New Jersey not allowing interlocks....... on smokstak.com there is an Onan generator sub-forum. One of the members lives in NJ and is a licensed electrician. I am quoting him.

Not saying to power a gas valve with DC without doing some tests. Just putting an idea out there so a competent tech/engineer can do some experiments to determine if it will work safely on your equipment. Would have to be a simple solenoid valve, no electronic circuit boards, unless you redesigned it.

Seen some Carrier 2 stage valves that also used a heated bi-metal to open a valve port, they would likely not work with DC as heater is resistive and lower DC voltage would likely not allow them to heat enough.