Level Switch

It is a electric reed switch....how can i check whether the switch is working or not

John

Reed switches will respond when a magnet is brought near them.

The other way to test whether the switch is working or not is to raise and lower the level a few times using water.

If it isn't working, and if it's still under product warranty, ask for a replacement under the warranty scheme.

this is not a reed switch its a proximity type magnetic switch without any relay.

i am sorry as i thought its a reed type.

Just from the sensor wires are connected to the No&NC contacts. and this switch is mounted on the Body of level indicator

I tried with the multimeter but didnt found changing states(NC to NO ).

John

Prox-switches usually need a power source in order to operate. How many wires does it have? What does the manual say about this instrument?

If its a reed switch just move the level switch stem ( using the float)up and down slowly it should get you the contact,

if its a prox switch do the connections as per the wiring diagrams and move the level switch stem( that is ussing the float) up and down to check if there is any movement.,

Am I reading this correctly--The wires are connected to the "NO" and "NC" portion with nothing attached to the "C" connection. If that is the case one of the wires needs to be moved to the common, find out what state the input expects to see when the switch is tripped (the tank is full) and wire accordingly. I agree there should be a power supply, bur an open and a closed will work also if the signal is a ground or has a high voltage potential.

If it is in a glass-envelope & have 2 leads .

And the reed having ferrous-piece attached is in parallel to magnet face.

If it is a level switch it cannot be a Dry-reed switch.

Level switch are mercury switches & mercury makes contacts when tilted to shift mercury to contacts side by gravity. not by a magnet.

Is there a model number anywhere on the switch: like one of these:-

From http://us.magnetrol.com/intermediate.aspx?menu=86

Does it look a bit like this?

Or this?

3 wires are connected only and there is no realy on that.

switch can be mounted on the indicator body and when flaot magnet comes near by it should switch.

but when i bring magnet to it ...nothing happened

Look at the picture in my post above: although the switch is described as "magnetic": it uses a standard microswitch

which is activated by a permanent magnet on a lever.

See if it has Mercury in it.

Hi Guest,

You will find that the reed switch is sensitive to the polarity of the magnetic field presented to it. Therefore if you are trying to test it by using a horseshoe magnet it probably will not change state. Use a bar magnet and try first one pole then the other. The reason for this phenomenon is that the reed assembly contains a magnet which holds the NC contact together against spring tension; presenting the external magnet overcomes this effect and the contacts spring apart (making to the NO contact).

Good luck,

Massey.

No sir it has no Magnet face in it but a ferrous piece with one of the reeds & operates on any pole N or S. or have a coil to operate by electro-magnet

Study the link at the end of this page:

Reed Switches

I suggest that always look at the end of page 7 you will find links with the items mostly under discussion

Have much details & images.

Have a fine day !!!!!

.

The replies sent by Hajee,Randall,Massey and PWSlack have covered up almost all possibilities of switching mechanism.

You haven't replied whether there is any bulb with mercury in it and wired at one end.

From your replies and knowing some of the Magnetrol switches, it looks like it is indeed a mercury switch but the tilting is achieved by a magnet and a lever mechanism that tilts the switch.A floating ferritic materical is enclosed in an SS tube that attracts the magnet on reaching a certain desired level.Thus the liquid will never be in contact with any electrical parts or magnet.

The floating mechanism may be stuck, a brocken spring,soldified liquid in the sensing tube .. could be the reason for the malfunction.As they say, when nothing else works, read the instructions manual!

Chuck Cowlagi

its not a mercury type .....it is magnet type and there is no relay also....from the sensor three wires NO,C,NC came out.i tested it with a bar magnet and multimeter to find out change of state. but nothong happens when a magnet brings near to the sensing part ....thats why i thought that power supply must be required.

if power supply is required then how to connect. as neutral supply to be connected where?

Rating is -120VAC/48VDC

Hi,

If there is continuity on the C/NC circuit and it refuses to change state the possibilities are that the contacts are 'fused' together by overcurrent or arcing. Remember that DC does nasty things to contacts and hence the big difference between the AC and DC ratings.

Perhaps also the poor thing found itself part of a circuit which under went a fault condition which by the time something else failed the 'micro-switch' had undergone an irrevocable transformation!

Buy a new one!

Massey

Regards:

View video how a murcry-Switc works And some definition

and more

http://www.assemtech.co.uk/productpages/tilt_tipover_switches_be.asp

Mercury Tilt Switch Demo <http://www.youtube.com/watch?v=SRgHHu1TmWk>

01:09 - 2 years ago youtube.com

Watch this video on youtube.com http://www.youtube.com/watch?v=SRgHHu1TmWk

Mercury Tilt Switch - Old School Accelerometer Watch this video on youtube.com

Thanks to all who replied me.

I got now the problem.

its a proximity switch. Supply should connect to load and Switch(C,No) in series. Then switch starts working. If any magnet brings close to it, then it will give switching action.