Gas and oil burner emergency switch placement.

[kwired]

You're in Massachusetts? Come on, you know the wiring inspector can request it, but he can't require it :happyno:

And while I can't cite a code reference, my understanding about the fire code in this state is that any oil-burner requires a safety shutoff switch in a different room from the burner, so in a typical single-family that would be top of the cellar stairs facing into the finished living space. And it is not a requirement for gas burners.

What about boilers? I think the requirements are for an emergency stop to shut down the controls because of the risks we have from a pressurized vessel, they don't care what the fuel source is.

 

[mgookin]

2010 International Fuel Gas Code

 

[gadfly56]

What about boilers? I think the requirements are for an emergency stop to shut down the controls because of the risks we have from a pressurized vessel, they don't care what the fuel source is.

If you mean a real boiler for a one or two-pipe residential steam heating plant, residential boilers don't really qualify as pressure vessels. ASME codes for "high" pressure don't kick in until you are at 15psig working pressure. Home boiler safeties are usually blowing off by the time they hit 7-8psig.

 

[iwire]

What about boilers? I think the requirements are for an emergency stop to shut down the controls because of the risks we have from a pressurized vessel, they don't care what the fuel source is.

I don't believe that was the intent at all.

I believe the intent was to stop fuel oil from being pumped into a fire.

I say this because in my home growing up they went even further, there was a spring loaded normally closed fuel valve right at the oil tank. It was held open by a piece of aircraft cable run across the cellar ceiling over to the oil burner. The cable had melt away pieces in it so that in the even of a fire the tank valve would shut.

When I look at the MA rules requiring this switch for oil burners it mentions it has to stop the flow of fuel oil.

 

[kwired]

We seem to have two different instances where some kind of safety disconnect is required and some are trying to combine them together.

One is for shutting off the fuel supply for oil burners - I don't have a lot of experience with oil burners, but apparently they need additional method of ensuring fuel supply is interrupted over other fuel sources such as natural gas or propane, when something goes wrong.

The other situation is for pressurized vessels involved when you have a boiler. The amount of pressure the vessel normally operates at I believe is what triggers such requirements. Once beyond that level they don't care what kind of fuel source you have they want control power interrupted. If the boiler is oil fired there may be additional requirements to ensure the fuel is stopped. Otherwise all the boilers I have been involved with just interruption of control power is all that was ever required. Most gas fired heating boilers we interrupt the main power to the boiler unit because it is simple to do, but I had an industrial boiler with 15 hp 480 volt draft blower on it and all they required was to interrupt the 120 volt control power with the safety switches near entrances to that room.

 

[iwire]

Here it is for those of us in MA, this applies to any fuel oil burner.

MA 527 CMR 4.03

(3) Oil Burner Controls.
(a) Oil burning equipment shall be provided with a means for manually stopping the flow
of oil to the burner. Said means shall be at a convenient and safe location.
This shall be accomplished by the installation of a quick-closing ? turn valve in the oil
supply line or by means of an electrical switch in the burner electrical circuit.
The valve or switch shall be plainly marked to indicate its purpose and placed outside the
entrance to the room where the burner is located or outside of the cellar/basement door at
first floor level in an exposed location clearly visible and readily accessible at all times.

Notice this regulation is aimed at oil flow.

As far as shut offs for pressure vessels I was under the impression the OP was asking about dwelling units. I have not heard of any code requirement for a switch in another room from a water heater. (Other than oil fired)

 

[kwired]

Here it is for those of us in MA, this applies to any fuel oil burner.

MA 527 CMR 4.03



Notice this regulation is aimed at oil flow.

As far as shut offs for pressure vessels I was under the impression the OP was asking about dwelling units. I have not heard of any code requirement for a switch in another room from a water heater. (Other than oil fired)

Domestic water heaters are not the same thing as a boiler. Boilers in dwellings often are small enough capacity that such disconnect possibly isn't necessary. Nobody would be enforcing such rules around here in a dwelling so I can't tell you for certain what is actually required. The high efficiency boilers of today pack a lot of heating capacity in a small enclosure compared to their ancestors. Have a problem with water flow through that boiler and it will overheat pretty quick compared to an older one - better hope the high limit switches and relief valves are functioning properly.

 

[mtfallsmikey]

Musings from the house plumber

Musings from the house plumber

As I remember, disconnects are covered in IMC (as they were in the old BOCA mechanical code). for boilers, or furnaces, placed one at the top of the steps, or within 5' of the appliance, also placed another switch close to the furnace/boiler for troubleshooting purposes, both with the red emer. switchplate.

 

[kwired]

As I remember, disconnects are covered in IMC (as they were in the old BOCA mechanical code). for boilers, or furnaces, placed one at the top of the steps, or within 5' of the appliance, also placed another switch close to the furnace/boiler for troubleshooting purposes, both with the red emer. switchplate.

Maybe it is just how you worded things, but you make it appear as though 5' from the appliance wasn't close enough for troubleshooting purposes:huh:

 

[mtfallsmikey]

Maybe it is just how you worded things, but you make it appear as though 5' from the appliance wasn't close enough for troubleshooting purposes:huh:

I may be wrong, but I believe that in the IMC 5' was the max distance away from the appliance that the switch could be placed. As far as troubleshooting is concerned, when I used to service oil/gas equipment, I liked to be close by, to check oil burner/gas burner operation, but there were times I was too close... "I only hit that reset button once"

 

[kwired]

I may be wrong, but I believe that in the IMC 5' was the max distance away from the appliance that the switch could be placed. As far as troubleshooting is concerned, when I used to service oil/gas equipment, I liked to be close by, to check oil burner/gas burner operation, but there were times I was too close... "I only hit that reset button once"

And yet NEC has always been happy with "within sight" for disconnecting means for any piece of equipment, and in some cases even ok with a lockable disconnecting means if not within sight. And if the item were 1/8 hp or less or less then 300VA - the lockable part isn't necessarily required.

Talk about uniformity in these codes.