Pumps and thermal cut outs

[jpadie]

Hi

i have a well pump about 23m down a well. It's under a quarter ton manhole cover ...

at certain times of year the pump cuts out, needing a manual reset. the reset is on the low pressure head at the top of the well - but under the manhole cover.

there is no scope (budget wise) for reboring the well to a greater depth. and no room to drop the pump further into the well.

My question is whether anyone knows how the thermal cut outs work and what would be needed to be build a remote reset device (I am ok with electronics). I've tried turning on/off the power supply to the pump but that does not reset the thermal cut out. There is frequently no one around able to get the man-hole cover off; and even if there is, that person has to lean quite a distance into the well to turn press the reset button (quite a lot of force is required on the button for the reset).

The pump controller is this one if it helps;

http://aquajulien.com/PressControl-...he-automatique-manque-d-eau-pompe-12899.html.

But I have tried a number of alternatives too.

thanks in advance for advice and suggestions
Justin

 

[Valvecrazy]

Almost everything in this world is designed with planned obsolescence as the major design characteristic. Date of death of most products is set by manufacturing. I didn't believe it either. Design life of pumps shortened on purpose? Yes they are. Plastic impellers, shorter motors (less heat sink), sealed bearings instead of grease-able, or three of five pads on a Kingsbury thrust bearing eliminated, all cut manufacturing costs and shortens life of pumps as intended.

Same thing goes for pump controls. See what controls pump manufacturers are pushing, and you will know which pump control is best for their cash flow. This is usually the opposite of what is best for the consumer.

In 1998 three different retired employees from three different major pump manufacturers told me this. They said their companies had tested a device that eliminates pump cycling and uses smaller pressure tanks. After testing this product the quote I was told was..."this company makes pumps and tanks, so any employee who mentions this device, which makes pumps last longer and uses smaller pressure tanks, will be terminated immediately".

This is especially true with small pumps like this. Design life is an AVERAGE of 7 years. This usually gets you past the 5 year warranty period, but not always. It wouldn't cost 5 bucks extra to make those pumps/motors last 30 years. An engineer for THE major submersible motor company in the US told me, "they had rather warranty half of all the motors they make, than make a motor that would last 30 years". They don't make them like they use to, for a reason.

 

[Artisi]

Of course everything has a predetermined life span. Possibly I wasn't clear in why use a controlling unit that will shorten the planned obsolescence of the pump unit, any smart pump company wouldn't select an add to their equipment at the detriment of their equipment. But all besides the point re the OP's question.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[itsmoked]

jpadie; If the button is facing upward why not just use two rod guides and a very light plastic rod. Mount it so it sits on the button and rises to an inch below the bottom of the manhole cover. Glue a little plastic plate on the top. Drill a 10mm hole in the manhole cover. When the thing needs resetting whip out a screwdriver and poke the little plastic plate thru the hole in the cover.

Purely a button extension.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[jpadie]

@Itsmoked
interesting idea. not sure whether practical for me: the pump controller is secured to a cross strut about 100cm from the top of the well. and it's mounted on the vertical (making the button accessible only from the front). I also don't relish the idea of drilling this manhole cover, but that's the least of the problems!

I think the answer is to butcher the controller or even to remove it totally. It's very straight forward to create a triac controller to turn the pump on at the same time that an irrigation actuator is fired; and to monitor current draw so that if there is any significant over/under current the pump would switch off. From what I understand above, that may be a better solution (perhaps with a flow meter added in) than the pump controller that is there at the moment.

 

[Valvecrazy]

Again, continually having to push a reset is not a solution, no matter how you do it. There are much better solutions available. If the pump is only used for irrigation from a irrigation controller, all you need is a pump start relay in the irrigation controller. Of course a dry run protector that senses amps is also needed to protect the pump in a low producing well application. If you need water on demand, like when just opening a hydrant, a constant pressure system with a regular pressure switch is very dependable.