Water level sensor to deactivated pump

[zephyros]

Hi guys,

I am looking for a water level sensor that will deactivate my

chiller and chiller pump if the water level falls belows a certain level.

Just a back ground. Currently, my chiller pump and return are both

in the last compartment of the sump. I am thinking of putting the pump

in the center compartment while leaving the chiller return in the last

compartment ... (with me so far )

This is the catch, my center compartment volume is last than my last

compartment.

Foresee problem

If main return pump is running, the water level shld level itself out.

Problem comes in if main return pump dies and the chiller pump is

still working. The water in the center compartment will be drawn to

the last compartment. And because the last compartment is larger

then the center, there is a possiblility that the water in the center

compartment will be drawn dry. Hence, I am looking for something that

will cut the power to the chiller pump if the water level is too low.

cheers

[beebeefl]

Hi guys,

I am looking for a water level sensor that will deactivate my

chiller and chiller pump if the water level falls belows a certain level.

Just a back ground. Currently, my chiller pump and return are both

in the last compartment of the sump. I am thinking of putting the pump

in the center compartment while leaving the chiller return in the last

compartment ... (with me so far )

This is the catch, my center compartment volume is last than my last

compartment.

Foresee problem

If main return pump is running, the water level shld level itself out.

Problem comes in if main return pump dies and the chiller pump is

still working. The water in the center compartment will be drawn to

the last compartment. And because the last compartment is larger

then the center, there is a possiblility that the water in the center

compartment will be drawn dry. Hence, I am looking for something that

will cut the power to the chiller pump if the water level is too low.

cheers

Glad that u bring this issue up. I am facing the same scenario

Hope an kind brother can advise a permanent solution...

[ciaolong]

float switch ?

[supremo]

yeah, i think you could use a float switch to trigger a realy. almost the same principle as a top up but instead of attaching the pump in the Normally Closed Output you attach your Pump/Chiller to the Normally Open output.

[apollo]

ok

may i know where to get this float switch and how much pls?

thanks

[ervine]

eh.... instead of deactivating it why don't you just activate a water top up pump?? Makes a lot more sense to me leh...

Float switches cost abt $15-20 bucks (cannot remember but around there) at sim lim tower basement, the shop that sells some solar cells

BUT.. float switch alone is not enough you need to get relays and some stuff.. go look up on a DIY auto-top up or just buy the tubby... i made mine abt 2 yrs ago for $50 (?) and it's still going strong today... donno where I would be w/o it!

[Oceandeep]

I belif the last compartment water will flow back to center compartment

if the return pump not working.

Cos the water level once over the wall of the two compartment,

the water will flow to the low side rite??

Correct me if I'm wrong!

[Rocky99]

I belif the last compartment water will flow back to center compartment

if the return pump not working.

Cos the water level once over the wall of the two compartment,

the water will flow to the low side rite??

Correct me if I'm wrong!

i agree with oceandeep, but i probably cannot visualise the problem well. but if u're worried abt the pump running dry in the centre compartment, how abt putting an inverted U tube connecting the centre and the last compartment. if yours is a powerful pump, use a fat tube. PVC pipe with 2 elbows also can. force out the air inside the U tube

[zephyros]

I belif the last compartment water will flow back to center compartment

if the return pump not working.

coz the last compartment is abt twice the vol of the center compartment,

and I'm worried that after ###### dry the center compartment, it is still

not enough to fill the last compartment till rim for the water to flow back.

but come to think of it, I've not consider the flow back of the water from the

display tank when main pump dies ... anyway, will test it out this weekend.

cheers

[supremo]

actually bro, what was wrong about having both pumps in the last compartment anyway? I'm a bit confused on what's the advantage of doing so that could outweigh all the concerns of having a pump in the middle compartment?

[zephyros]

actually bro, what was wrong about having both pumps in the last compartment anyway? I'm a bit confused on what's the advantage of doing so that could outweigh all the concerns of having a pump in the middle compartment? 

k ... this is the 2 school of thots for chiller placement.

1) chiller in/out in the same compartment (ie last) u are re-chilling ur

chilled water from the chiller. doing so ur chiller will "seems" to be able

to bring down the temp much faster. However, this is a false reading and

will result in the chiller turning on-off very frequently.

2) chiller in (center) and out (last). the water in the center and last compartment

does not mix, and thus u r chilling the water from the main tank only. By doing

so, it will take longer for the chiller to bring down the temp, but it too takes longer

for the water temp to raise. hence, chiller will turn on/off less frequently but for

longer period of time.

hmmm ... no one can say which is better, but from an electronic pt of view,

turning on/off too frequently is not so good to the device itself.

cheers

[supremo]

ohh, the chiller output goes back to the sump now i get it i've always set up mine as an additional return to the display tank

if that's the case, i think the 2nd option is better ( oh oh, dangerous statement here). cause from what I understand about motors and compressors, the starting up draws more power.