douggiestyle
New member
using a gfi outlet, add a float switch that closes at low water causing a short in the gfi there by causing the gfi to open. shutting off the pump plugged into it.
comments suggestions?
comments suggestions?
low water pump cut off
- Thread starter douggiestyle
- Start date
BeanAnimal
Premium Member
Doug, this is where a latching circuit is perfect. Once the water drops and lets the latch fall out, it can not be reset unless the latch is reset by filling the sump to the "min" level latch, or a manual reset occurs.
As you likely know, using a single float for lowe level conditions will cause osscilation and pump failure. When the water drops enough to stop the pump, the pump will drain it's contents to the sump, allowing the float to rise and restart the pump. This will continiu in an endless cylce until the pumps frys or the water evaporates enough to stop the cycle.
As you likely know, using a single float for lowe level conditions will cause osscilation and pump failure. When the water drops enough to stop the pump, the pump will drain it's contents to the sump, allowing the float to rise and restart the pump. This will continiu in an endless cylce until the pumps frys or the water evaporates enough to stop the cycle.
douggiestyle
New member
well as bryanth points out the gfi could fail. but the fish fry... i dont know if that could occur without an electrical fire. but as you mentioned beanimal the gfi would be the latch. it would not come back on without reseting it.
the plus with the gfi is they are well designed against failure and also allow testing. (the tesing mechanism creates a short within the gfi). actually you could posibility wire the testing switch to the float switch instead.
the plus with the gfi is they are well designed against failure and also allow testing. (the tesing mechanism creates a short within the gfi). actually you could posibility wire the testing switch to the float switch instead.
douggiestyle
New member
ok quick redesign gfi with neutral to ground fault detection. now you could simply run the neutral to the ground through the float switch. almost no current. no chance of fish fry or worse me fry. and still get the same results. shut down til reset.
Last edited:
BeanAnimal
Premium Member
The N->G detection would work. I think the point is that if you create sutch a connection, and the GFCI does fail, then you have created a wiring fault that is possibly a safety concern.
The GFCI test button is a momentrary contact switch that trips a small breaker in the outlet. It does not create a permanent H->G fault until the unit is reset.
Your idea would work, I just would not want to defend against it with the insurance company if there were a problem.
Scenario 1.) house burns down becuase your DIY top-off system or aquarium create a fire. You have a leg to stand on because your just a DIY maroon trying to keep fish.
Scenario 2.) house burns down because your modified GFCI creates a hazzard. You are going to fight an uphill battle due ot the modification of a safety device.
Kind of subtle, but definatly something to think about.
The GFCI test button is a momentrary contact switch that trips a small breaker in the outlet. It does not create a permanent H->G fault until the unit is reset.
Your idea would work, I just would not want to defend against it with the insurance company if there were a problem.
Scenario 1.) house burns down becuase your DIY top-off system or aquarium create a fire. You have a leg to stand on because your just a DIY maroon trying to keep fish.
Scenario 2.) house burns down because your modified GFCI creates a hazzard. You are going to fight an uphill battle due ot the modification of a safety device.
Kind of subtle, but definatly something to think about.
douggiestyle
New member
The GFCI test button is a momentrary contact switch that trips a small breaker in the outlet. It does not create a permanent H->G fault until the unit is reset.
never said it did.
The N->G detection would work. I think the point is that if you create sutch a connection, and the GFCI does fail, then you have created a wiring fault that is possibly a safety concern.
but if the gfi does fail the posibility of the pump over heating and burning down the house exists. which is the lesser of two evils.
i wouldn't actually modify the gfi only the how it is used.
the only danger of having the neutral and ground connected would be as such. say your drill has a metal casing and the neutral and ground are connected you turn the drill on and grab the cold water pipe or what ever and zap. the gfi protects against that. having the neutral and ground connected in an inclosed housing would create no danger.
"maroon"? you a bb fan?
never said it did.
The N->G detection would work. I think the point is that if you create sutch a connection, and the GFCI does fail, then you have created a wiring fault that is possibly a safety concern.
but if the gfi does fail the posibility of the pump over heating and burning down the house exists. which is the lesser of two evils.
i wouldn't actually modify the gfi only the how it is used.
the only danger of having the neutral and ground connected would be as such. say your drill has a metal casing and the neutral and ground are connected you turn the drill on and grab the cold water pipe or what ever and zap. the gfi protects against that. having the neutral and ground connected in an inclosed housing would create no danger.
"maroon"? you a bb fan?
BeanAnimal
Premium Member
bb? As in Bug Bunny... yup I grew up on bugs and elmer. THough I think I first learned the saying from dearl old dad or grandpa.
"what a maroon"
"what a maroon"
douggiestyle
New member
"what a maroon" yeah i use with my kids all the time. that and "idjit galoot"
douggiestyle
New member
so im looking at this and if you notice the gfi only cots off the hot leaving the neutral and ground connected indefinately. its not a problem. only if the neutral and ground are connected in an enegized device is it a problem. then there is a possibility of chassis or what ever also becomeing energized, giveing the user a zap.
you may have already exoerienced this. your in the basement in your bare feet and you lean against the frig (or what ever) and feel a tingle. i had a guitar amp that did it. only in bare feet and i could only barely feel it in my forearm when i rested it on the amp. that said if that amp had been plugged into a gfi the gfi would have tripped. so why dont dont we have a gfi on every outlet. because the powers that be, dont believe it to be a very high risk except in a bath, outside or the kitchen etc. what ever the code says. so conecting the ground to the neutral in of itself creates no safety risk. and well actually the neutral and the ground are always connected, in the electrical box.
so the matter is, if a gfi (sorry gfci, old habits die hard) is reliable. ive often read were gfci is not reliable in that it trips when unnecessary i would be willing to bet that in most of those cases some type of short occured, possibly condensation in the outlet. ive had that happen in the outlet next to the stove. it could have been anything. but still the gfi worked. and if they are unreliable dam the tank why am i trusting my kids with these things in the bathroom.
what is a more reliable option?
BeanAnimal
Premium Member
GFCI relys on a small comparator circuit. They do fail sometimes. GFCI is also prone to nuisance tripping when used with large current draw devices that produce a lot of EMF. Motors and ballasts are such devices. Some GFCI comparators are much better than others, and less prone to nuisance tripping.
The guitar AMP most likely shocked you because the plug was not polarized (or it even could have been). If you notice most old tube amps like that have a polarity switch on them. One leg of hte AC is coupled to the chasis via a capacitor. The polarity switch determines which leg. Lets say you plug (2) fender twin reverbs in and hte siwtches are not set the same. Plug the guitar into one amp and a mic into the other... care to know what happens when your fingers touch the strings and your lips touch the mic? Your bare feet and a tube amp are not a good idea EVER. If the coupling cap is leaky or shorted, you become neutral due to the superb contact your barefeet are making.
More reliable, I dunno. I use designed a latch circuit for use with a heavy duty contactor, but have not yet implemented it because I will never have a low water problem. My sump is huge and if I do have a low water problem... well I have other problems that are a lot worse. I will still implement the low fail safe but it is not on the list of priority items.
The guitar AMP most likely shocked you because the plug was not polarized (or it even could have been). If you notice most old tube amps like that have a polarity switch on them. One leg of hte AC is coupled to the chasis via a capacitor. The polarity switch determines which leg. Lets say you plug (2) fender twin reverbs in and hte siwtches are not set the same. Plug the guitar into one amp and a mic into the other... care to know what happens when your fingers touch the strings and your lips touch the mic? Your bare feet and a tube amp are not a good idea EVER. If the coupling cap is leaky or shorted, you become neutral due to the superb contact your barefeet are making.
More reliable, I dunno. I use designed a latch circuit for use with a heavy duty contactor, but have not yet implemented it because I will never have a low water problem. My sump is huge and if I do have a low water problem... well I have other problems that are a lot worse. I will still implement the low fail safe but it is not on the list of priority items.
BeanAnimal
Premium Member
Please also note that a GFCI WILL NOT help you or your family in a case where the shock hazzard is from hot to neutral.
douggiestyle
New member
never owned a tube anything except the tv and microwave. but i also had an old frig that did the same thing. anyways that is what would happen if the neutral and ground were connected in an energized appliance. or worse, hence the use of gfci.
i suppose if your sump is lage enough and the water top of always works and you can catch it if it doesnt. sure, no need for one. i will most likely never use one. the few instances were the top off float gets stuck (time for a cleaning) i am able to fix it in time before any damage occurs. i am home every night of the week. then again i may. dont know yet.
false tripping can occur if the the line from the ballat to the lights are to long. and in the case of using a ballast with a gfci although the ballast will be protected the bulbs will not they are isolated. to prove this yourself plug a small ac to dc tranformer in (most cell phone chargers will work) then short out the end you would plug into the cell phone (paper clip will work fine) the gfci does not trip. that is why some ballsts have a gfci built into them. to protect if the bulbs were to fall in the water.
go steelers.
BeanAnimal
Premium Member
Yeah anything past the ballast or driver circuit on a light set is part of the load and has no effect on the GFCI sensing. The same is true for just about any device isolated by a transformer or other power shaping or conversion device or circuit.
The reason you were shocked by the fridge is that you made a better ground than the X feet of wire to the panel. Your body conducted power that should have traveled down the neutral. ( I am sure you already understand this)
My sump woul dhave to evap about 30 gallons to expose the pump. At this point salinity would be more of an issue. I am also not to concerened about a leak diverty water away from the system (it could happen I guess, and that is why I will some day setup the low level failsafe).
Bean
The reason you were shocked by the fridge is that you made a better ground than the X feet of wire to the panel. Your body conducted power that should have traveled down the neutral. ( I am sure you already understand this)
My sump woul dhave to evap about 30 gallons to expose the pump. At this point salinity would be more of an issue. I am also not to concerened about a leak diverty water away from the system (it could happen I guess, and that is why I will some day setup the low level failsafe).
Bean
BeanAnimal
Premium Member
I am a Dallas fan... but hope the steelers do well (for my own safety this afternoon...)
douggiestyle
New member
ha ha... i used to be a dallas fan, but i was a kid and didnt understand the reprocations of such a thing in pittsburgh. i soon learned the error of my ways when they escorted my out of the auditorium in elem. after i rooted for the cowboys while watching nfl films. the year was 1978.
douggiestyle
New member
<a href=showthread.php?s=&postid=6556000#post6556000 target=_blank>Originally posted</a> by douggiestyle
if you notice that this diagram shows only the hot being disconnect. in a new gfi the hot and neutral must be disconected. thereby adding additional safety.
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