Looking for a bit of help in regards to a lift station installation. Where could I obtain the proper guidelines and NEC references. The job consists of adding a control panel (outdoors) next to the new well. The grey areas are if explosion proof fittings/Chico are to be used before conduit enters cabinet, type of conduit used and sealing of conduit inside of the well. It will contain sanitary and minimal sewage. I need to run 2 conduits for the pumps and 1 for a level probe. I was going to drill through the pre-forms at the top elbow out/stub-up to panel. Thanks.
On a job like you described, we want detailed, sealed engineering prints, before any bidding or work is started.
Reason for requiring the sealed prints is, we do not have professional design build coverages, i don't know of many contractor insurances that do have design build coverage, a large number of EC's just dive in and do them, without understanding all the risks involved, my view is protect yourself, and do it right.
I have done several lift stations in the past few years. Here is what I did, and what I was responsible for. Run the power to a sewer contractor supplied control cabinet. Mount the control cabinet. Run 2- 2” conduits from control panel to pit. Run 1- ¾” conduit and 3- #12 wires (blk, wht, grn) from control panel to pit and install an outlet for a sump pump. All other work was completed by the sewer contractor, or lift station representative. I don’t know if the used chico or not, as I was not responsible for that portion of work. In our proposals I state it this way.
1-Lift station power feed XX amps XXX volts. Lift station work as follows: Mount and install lift station control panel (supplied by others). Pipe and wire feed from building to control panel disconnect switch. Mount and install 1- outlet in pit to control sump pump, others to wire to control panel. Run 2 – 2” conduits from control panel to lift station pit. Concrete control pad by others. All other work pertaining to the operation of the lift station to be preformed by others.
Re: LiftStation Installation#72010 11/15/0605:46 AM11/15/0605:46 AM
I must clear up that this installation is at a plant I am currently employed at. My main concern is if this meets explosion-proof criteria and where I could formally find this info - from a book or from those-in-the-know. I may plan on using explosion-proof fittings anyway, but if not necessary I would rather not (to eliminate splices in well during future repairs). What materials are needed from well to panel - RMC? aluminium rigid? I know PVC is not an option. I will not be adding any type of receptacle - rather hard-wire from 3P 480VAC pumps to motorstarters in the panel.
Re: LiftStation Installation#72011 11/15/0609:52 AM11/15/0609:52 AM
This is a subject that is under review for the next edition of the NEC.
As it now stands, only a registered 'professional engineer' is deemed as qualified to make the determination of where the 'classified' areas are.
There is a proposal the change this to "qualified person." This is NOT a loophole- nor should it be considered a meand for just anyone to wave a wand and say "I'm qualified." Rather, the proposal asserts that having a PE license does not infer any expertise in this area at all, and that there are many other professions out there that do have expertise here.
As a general rule, it is NEVER the responsibility of the electrician to make this decision. Don't let anyone stick you with it; there is too much at risk.
Nor is someone's assertion that "they do it all the time" enough. If they won't sign, their opinion is just eyewash. At the very least, rely upon your local inspector; he ought to know where to get the information.
Re: LiftStation Installation#72012 11/15/0611:57 AM11/15/0611:57 AM
I inspected several of these for the state. They were fairly small stations in parks. The pipe was always steel RMC with seal offs below the listed cabinet assemblies. I think the only way you can avoid the seal off is if they can demonstrate a certain amount of air turnover in the pit. That is usually the last thing they want to do because of the smell so they accept the classified location designation without question.