Working in Class 1 Div 1 and Div 2

[Rfoster66]

I am running conduit in an active C1D1 area (I don’t no the groups at this point.) It is a raw sewage dump site. How can I make it safe to use a Hilti hammer drill and/or other power tools to run conduit? The room does have a garage door and 2 man entry doors, 1 exhaust and 1 supply fan. What, if any safe guards can be set in place. Is there a code reference or best practices sited some where for such work? Looking for literature or sources as well. Same questions for C1D2 in very similar locations.

Thank you in advance. Ryan

 

[petersonra]

You need what's colloquially referred to as a hot work permit. Effectively what is done is to temporarily reclassify the area as non-hazardous. This can be done in various ways, but requires some kind of thought and is not as simple as just opening a door to get a little extra air.

Often some kind of monitoring is required via gas detectors. It seems likely that whoever owns this sewage station probably already has a procedure for dealing with this problem because the reality is every once in a while you have to work in such an area.

I don't believe that you will find any code that tells you how to deal with this situation. You will probably want to discuss it with the sewage station owner and decide what is appropriate. If The owner does not have a procedure in place, you may need to hire a professional engineer or other suitable person to create one.

 

[Rfoster66]

You need what's colloquially referred to as a hot work permit. Effectively what is done is to temporarily reclassify the area as non-hazardous. This can be done in various ways, but requires some kind of thought and is not as simple as just opening a door to get a little extra air.

Often some kind of monitoring is required via gas detectors. It seems likely that whoever owns this sewage station probably already has a procedure for dealing with this problem because the reality is every once in a while you have to work in such an area.

I don't believe that you will find any code that tells you how to deal with this situation. You will probably want to discuss it with the sewage station owner and decide what is appropriate. If The owner does not have a procedure in place, you may need to hire a professional engineer or other suitable person to create one.

thank you, I will need to find out if they have this. If they do not, where can I find info to learn how to reclassify? We do have MSA gas detectors, I would assume I will need to know the gases present and LEL as well. Thanks again.

 

[petersonra]

thank you, I will need to find out if they have this. If they do not, where can I find info to learn how to reclassify? We do have MSA gas detectors, I would assume I will need to know the gases present and LEL as well. Thanks again.

I will reiterate what I posted before.

If The owner does not have a procedure in place, you may need to hire a professional engineer or other suitable person to create one

.

Gas detectors might be part of the solution. Presumably if you have gas detectors you have people to operate them who have current certificates showing they have been properly trained. Presumably the gas detectors also have current calibration certificates.

Just curious, are your gas detectors intrinsically safe for the area you are looking at?

I do not think you should attempt to create this kind of procedure on your own. If the owner does not have one, you need to find somebody who knows how to do this. The owner's insurance company may have some ideas.

 

[don_resqcapt19]

Gas detectors are typically rated for use in an area where the gasses they are designed to detect are present.
You do need to do a "bump" test each day with a calibration gas suitable for the detector that you are using.

 

[petersonra]

Gas detectors are typically rated for use in an area where the gasses they are designed to detect are present.
You do need to do a "bump" test each day with a calibration gas suitable for the detector that you are using.

I know. I was trying to subtly nudge him into thinking about some other issues such as does he have suitable equipment for using in a classified area? Volt meters, battery powered watches, cell phones, tablet computers, etc. Might not be appropriate for that area.

Just to go in and debug things, or even just look around, may turn out to be an issue as well.

 

[mannyb]

Im not an expert on this but I will say that with all the sensors and monitors in the room that even the dust that the hammer drill will create could set off alarms. Been there done that. I agree, most of these places have procedures for this kinda stuff. The last think you want to have fire dept show up at $500 false alarm fee and probably get kicked off the job.