Boiler emergency e-stop

[JeremyJones]

I have a boiler with a 20amp disconnect switch. The owner wants to add 2 mushroom head E-stops. If there is no e-stop terminals in the boilers control panel whats the best way going about this?

 

[SheffSimon]

I have a boiler with a 20amp disconnect switch. The owner wants to add 2 mushroom head E-stops. If there is no e-stop terminals in the boilers control panel whats the best way going about this?

Whats the reason behind wanting some estop pushbuttons?

If there is a genuine need highlighted by a risk assessment, then a method of removing the power from the boiler by means of a contactor might be suitable, or an emergency gas shut off valve. The design requirements all depend on the level of reliability required to put the boiler into a safe state. Whatever gets done, if its done properly, it will be more complicated than adding a couple of pushbuttons. And the responsibility will be yours as the designer, in the event of a accident.

You could just wire the buttons in series with the thermostat, or whatever fires the boiler. They won't be emergency stop pushbuttons in that case.

 

[Darkwood]

Are we talking a commercial or industrial boiler here?
As above - what warrants E-stop system for a boiler, is there a perceived danger trying to be averted here and what does the risk assessment classify the cat' of E-Stop system needed if any.

Let's just clarify here that the actuators usually used for E-Stops are not E-Stops unless the control system has an E-Stop system in place, even the twist release etc can only be called functional stops regardless of what they look like if the controls behind them are not designed around a suitable E-Stop system that would comply for the situation.

 

[JeremyJones]

Are we talking a commercial or industrial boiler here?
As above - what warrants E-stop system for a boiler, is there a perceived danger trying to be averted here and what does the risk assessment classify the cat' of E-Stop system needed if any.

Let's just clarify here that the actuators usually used for E-Stops are not E-Stops unless the control system has an E-Stop system in place, even the twist release etc can only be called functional stops regardless of what they look like if the controls behind them are not designed around a suitable E-Stop system that would comply for the situation.

It's a boiler at a commercial building for infloor heat.

 

[Spoon]

It's a boiler at a commercial building for infloor heat.

As above, so why have they requested an E-stop?

Oh, and welcome to the forum mate.

 

[JeremyJones]

As above, so why have they requested an E-stop?

I have no idea... it has a 20amp disconnect switch already. But there's 2 doorways they want the e-stops by. The best way I can think of is have it all in series with 12awg wire,thats if the e-stops can handle that load.

 

[Darkwood]

You can't just go fitting E-Stops without understanding why they are been requested or how they integrate into the control system as a fail safe option, it would require a risk assessment, I also think your customer is not fully understanding the difference between a latching functional stop and an actual E-Stop system, without knowing why these are to be implemented and the hazards they are trying to avert then we cannot advise.
If they are been implement to avert a hazard/danger then a risk assessment is needed and a suitable design regarding the cat' of safety system needed to be implemented, I think you need to have a chat with the customer just to clarify what we are looking at, I suspect the customer is loosely applying the term E-Stop simply to mean the style of actuator.

 

[JeremyJones]

You can't just go fitting E-Stops without understanding why they are been requested or how they integrate into the control system as a fail safe option, it would require a risk assessment, I also think your customer is not fully understanding the difference between a latching functional stop and an actual E-Stop system, without knowing why these are to be implemented and the hazards they are trying to avert then we cannot advise.
If they are been implement to avert a hazard/danger then a risk assessment is needed and a suitable design regarding the cat' of safety system needed to be implemented, I think you need to have a chat with the customer just to clarify what we are looking at, I suspect the customer is loosely applying the term E-Stop simply to mean the style of actuator.

They just want to hit the e-stop and kill power to the boiler

 

[Darkwood]

They just want to hit the e-stop and kill power to the boiler

Unfortunately it is not as simple as that, an E-Stop is a system implemented for safety and it needs to be carefully designed, you need to talk to the customer about why there is a need to stop the boiler remotely or in a emergency, what perceived dangers exist, until we establish that we cannot advise.

 

[Timbo]

I think that as the OP is in Florida we should call in @Megawatt to advise.

 

[JeremyJones]

I think that as the OP is in Florida we should call in @Megawatt to advise.

Now im thinking 2 e-stops to a shunt breaker

 

[Spoon]

Now im thinking 2 e-stops to a shunt breaker

Now I'm thinking that you are not quite understanding the function of an E-stop.
Please read @darkwood post #9 again.

 

[JeremyJones]

Now I'm thinking that you are not quite understanding the function of an E-stop.
Please read @darkwood post #9 again.

Hit the e-stop and the boiler shuts off,too easy

 

[Lister1987]

Hit the e-stop and the boiler shuts off,too easy

As you're stateside there will no doubt be local, regional or federal requirements around e-stops, Thier functions, mode of operation etc (NFPA 79, ISO 13850, 2006/42/EC and IEC 60204-2 come to mind).

 

[Spoon]

Hit the e-stop and the boiler shuts off,too easy

Glad you have digested all the advice you have received and now know what to do mate...