Sewage Pump Station Classification
- Thread starter spsnyder
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- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
Re: Sewage Pump Station Classification
I'd like a better description of the installation before I comment.
I'd like a better description of the installation before I comment.
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
Re: Sewage Pump Station Classification
There is an NFPA document, 820, that covers these installations. But the AHJ would had to adopt it. Typically ww wet wells are class 1 div 1. In washington state we have a state code rule that exempts residentail sewage systems from being classifed.
You should check with your ahj.
There is an NFPA document, 820, that covers these installations. But the AHJ would had to adopt it. Typically ww wet wells are class 1 div 1. In washington state we have a state code rule that exempts residentail sewage systems from being classifed.
You should check with your ahj.
Re: Sewage Pump Station Classification
I noticed you are from NY. There is a publication, the Ten States Standards that classifies all areas of Sewage Treatment Plants and Pumps Stations. A pump station that handles raw sewage in NY is usually considered a Class 1 Div 1 location inside the wet well. The area surrounding the wet well is usually not classified. As stated above, you must check with the AHJ.
Stu
I noticed you are from NY. There is a publication, the Ten States Standards that classifies all areas of Sewage Treatment Plants and Pumps Stations. A pump station that handles raw sewage in NY is usually considered a Class 1 Div 1 location inside the wet well. The area surrounding the wet well is usually not classified. As stated above, you must check with the AHJ.
Stu
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
Re: Sewage Pump Station Classification
Personally, I'd still like more specifics on the installation, but determining local practice is certainly a valid comment as Tom and Stu have recommended.
Without a local exemption like Washington, you are most likely in a Class I, Division 1, Group C&D location. The principal components of "sewer gas" are methane ("D") and hydrogen sulfde ("C"). Since you are only discussing a junction box, the "T" rating is irrelevant.
Personally, I'd still like more specifics on the installation, but determining local practice is certainly a valid comment as Tom and Stu have recommended.
Without a local exemption like Washington, you are most likely in a Class I, Division 1, Group C&D location. The principal components of "sewer gas" are methane ("D") and hydrogen sulfde ("C"). Since you are only discussing a junction box, the "T" rating is irrelevant.
Re: Sewage Pump Station Classification
Thanks for the responses. The system is a residential system. The sewgage enters a septic tank. The effluent is conveyed to a pump station that lifts the effluent to a subsurface treatment system. The pump station is vented with a 2" PVC pipe and U. There is a 2" conduit that enters the tank that ends in a junction box within the tank. The power for the pumps and the float wiring enter the box. The pumps are effluent pumps that are not explosion proof.
Thank you for the input, I will call my DOH and look at Ten States.
Thanks for the responses. The system is a residential system. The sewgage enters a septic tank. The effluent is conveyed to a pump station that lifts the effluent to a subsurface treatment system. The pump station is vented with a 2" PVC pipe and U. There is a 2" conduit that enters the tank that ends in a junction box within the tank. The power for the pumps and the float wiring enter the box. The pumps are effluent pumps that are not explosion proof.
Thank you for the input, I will call my DOH and look at Ten States.
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
Re: Sewage Pump Station Classification
From this description, I stick by my previous comment. The submerged pump motors aren't required to be XP although there is a rather pesky semi-colon in 501.8(A)(4).
The level switch should be identified for Class I. Its the item I'd be the most concerned about.
I imagine some of these complexities may be the reason Washington exempted residential applications. The actual risk is extremely low for the amount of genuinely ignitable material involved.
From this description, I stick by my previous comment. The submerged pump motors aren't required to be XP although there is a rather pesky semi-colon in 501.8(A)(4).
The level switch should be identified for Class I. Its the item I'd be the most concerned about.
I imagine some of these complexities may be the reason Washington exempted residential applications. The actual risk is extremely low for the amount of genuinely ignitable material involved.
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
Re: Sewage Pump Station Classification
I once saw a manhole cover that landed across the street due to an explosion in a ww liftstation wet well. it was likely due to gasoline that was in the sewer. I've been in many ww manholes, (with gas sniffers and ventilation) Most test OK for oxygen and combustables without ventilation. But you never know, it all depends on the loading.
I once saw a manhole cover that landed across the street due to an explosion in a ww liftstation wet well. it was likely due to gasoline that was in the sewer. I've been in many ww manholes, (with gas sniffers and ventilation) Most test OK for oxygen and combustables without ventilation. But you never know, it all depends on the loading.
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