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#188573 - 08/18/09 10:02 AM ckt size
watersparkfalls Offline
Member

Registered: 03/08/05
Posts: 210
Loc: Washington...Not DC
I have a septic motor running amps 12 and a LRA of 40.
Septic guy has botched this septic up (don't get me started) Now he has a 240 volt motor(this one mentioned) I have it wired 120volt now and can change it to 240 easy enough without having to open up tank lid(float controls- power in to one float-which feeds through second float and spliced to motor-neutral tied to motor)so you see easy to convert 120 at panel to 240 and run separate power for low voltage alarm.
My question is "at 12 amps would 20 amp circuit be enough to feed motor and start up current"?

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#188574 - 08/18/09 10:43 AM Re: ckt size [Re: watersparkfalls]
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9012
Loc: Estero,Fl,usa
I bet it will be fine.
_________________________
Greg Fretwell

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#188585 - 08/19/09 06:41 AM Re: ckt size [Re: gfretwell]
sparky Offline
Member

Registered: 10/18/00
Posts: 5542
not that it's relevant to your Q watersparkfalls , but i'm reading a particular design issue that's a pet peeve of mine here

i like all the leads for the motor, float controls, and or alarm(s) to be passed through a conduit uncut to a JB, and then that conduit sealed

imho, i have not yet seen a 'septic proof' JB that can be utilized and survive a methane atmosphere for any length of time

also, a disco placed as close as possible is also a consideration

and.....i'm really really tired of holding my breath trying to get meter readings on a failed system

~S~

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#188590 - 08/19/09 11:34 AM Re: ckt size [Re: sparky]
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9012
Loc: Estero,Fl,usa
I never did a septic pump but when we did lift pumps I wanted seal offs on the conduits coming out of the pit if they couldn't demonstrate that they turned the air over to reduce the concentration of methane.
_________________________
Greg Fretwell

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#188591 - 08/19/09 12:13 PM Re: ckt size [Re: gfretwell]
renosteinke Offline
Cat Servant
Member

Registered: 01/22/05
Posts: 5299
Loc: Blue Collar Country
I do not advise that any attempts be made to 'seal' the conduit. I do like the idea of a junction box NEXT to the sump, though.

Indeed, I favor a grossly oversized conduit, and might even like it if there were separate conduits for the pump and float cables.

Let's look at this a bit closer. First, what is a 'junction box?? I most certainly do NOT mean any sort of metal box with a gasket. Rather, I am referring to the fiberglass or concrete 'handholes' that have open bottoms. These are set atop a layer of gravel, and (ideally) have the conduits use a sweep to enter them vertically, from the bottom.

Will an overfilled sump also fill the box? Yes. Rain and ground water will also enter. The open bottom means that they will also drain.

The reason for large conduit is that, over time, the cable insulation swells considerably. This can make it impossible to replace the entire length of cable.

Splices in the box are made using some sort of waterproof method; I prefer simple wire nuts, dipped in Scotch-Kote, and left pointing 'up.'

If you have to splice in the pit, do it leaving enough cable that the next time you can do it from ABOVE the pit. I like the Ideal UF splice kit for power leads; it has a 4-port set screw arrangement that allows for ready replacement the next time, or for easy rotation reversal of three phase pumps.

If you have to replace an existing junction box in a pit, use a PVC one. The 'home centers' carry very affordable ones by Carlon; I think a 12x12x4 cost me about $25. These are nice NEMA-4 boxes with proper gaskets. I use Scotch-kote to secure the gasket to the cover. Where cables enter, I use the fittings that have rubber grommets in them.

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#188597 - 08/19/09 07:58 PM Re: ckt size [Re: renosteinke]
sparky Offline
Member

Registered: 10/18/00
Posts: 5542
well we're forgetting the disco within sight here, aren't we?

best possible scenario, all wires come up to a loto switch on a post by the sewer entrance, there's usually enough SO cord

funny how the manufacturer's instructions always say 'to be installed by a licensed electrican' , yet mention nothing of it, and show pictorals of their own 'sewer proof' boxes without one eh?

the first consession is the nothing visible one, where a greenlee ground box may be used to displace the splicing from the methane (and from the worker being exposed to it, for you osha compliant sorts)

the last thing i'd do is a pvc box in the sewer hole. I tell people it won't last, and it usually doesn't.

last one i did , the lady insisted on not seeing anything in her pristine back yard, so it was the pvc box, the so cord connectors, as well as the small split bolt conn coated with scotchcote, sealed with duc seal, taped with splice tape within it aka= bomb proof

the lady had the access hole covered with 6" of dirt & grass...

it failed within a years time.........

take it from a dude who's crawled in enough sh*tholes

don't make a splice of any sort in them, unless your really really tolerant.....

~S~

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#188606 - 08/19/09 11:10 PM Re: ckt size [Re: sparky]
watersparkfalls Offline
Member

Registered: 03/08/05
Posts: 210
Loc: Washington...Not DC
I am not sure we are talking about the same septic design.
The type I am referring to is a 3 tank system(because its on a lake[two is more typical}) The first tank is solids, when the water level reaches spill over then that black water goes into tank #2 which spills over into third tank via a filter that I think makes this gray water(this I am not sure of though) any way inside this tank sits said 12 Amp motor which pumps it 500+ feet to drain field tank which has two tanks up there.
Anyway inside #3 tank is a plastic JB which power, float and motor splice using the blue wet location wire nuts. The low voltage high alarm is run through LB. In both cases using direct burial wire outside tank back to house, where disco is mounted. I changed breaker to 2 pole 20Amp and it is working fine. Thanks for all the posts, interesting.
H2O

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#188610 - 08/20/09 03:54 AM Re: ckt size [Re: watersparkfalls]
sparky Offline
Member

Registered: 10/18/00
Posts: 5542
I've actually done that same setup myself watersparkfalls

for the most part, the diggers here install a pipe directly into the older style one tank systems

i've gone toe to toe with many of them, posing that i don't dig, you don't wire....

they mainly view me as a professional snot, which i make no bones about

i'm older, uglier, and if anyone wants a trouble free system i want it done my way

~S~

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