# how to connect light indicator



## rajeshmarndi (Aug 24, 2009)

I have a electric water heater (geyser) in India, but the two light indicator(one for power and other for heating) are burnt out and they were therefore removed and the wire were black taped.

Those indicator connecting wire were placed parallel.

I want to put back the indicator with neon lamp indicator but since they were removed I couldn't know if there were any resistor connected with the indicator.

Can I use any neon lamp indicator and appropriate resistor.

If I am right, the parallel connection will increase the current through the load(water heater).

So how to connect the indicator and resistor.


Water heater specification

230 v, 50 hz
input 2kw , capacity - 15 lit


Thanks.


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## Done_Fishin (Oct 10, 2006)

Do you know what type of indicators were previously attached ??

if we are talking about mains voltage indicators (ie 220 ~ 240 Vac) then yes any Neon indicator would suffice provided that it either has the appropriate resistor built in or is connected in series externally. A Neon is not polarised but any wires and external components should be totally isolated so as to prevent possibilities of short circuiting.

for the power side the Neon & resistor should be mounted across the LIVE / Neutral incoming cable whilst the "Heating" side would be mounted after the thermostat to Neutral. In this way you will always have the power Neon alight when AC is applied and the Heater Neon will light when the Thermostat is allowing current to flow to the heater element and will go off when the thermostat has reached the designated temperature.

Ensure that the mains power is switched off whilst doing this work to avoid the possibility of electric shock.


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## rajeshmarndi (Aug 24, 2009)

I have attached the connection.

I don't know I am not getting current at D, when the geyser is on. But the water is heating. I am also getting current at C when it is heating and no current when the heating is off.

I have connected power indicator at G & H and thermostat heating indicator at C & D and I do not get any light.


I am connecting neon indicator and resistor (82K) in series. Power supply is 220 V.

Thanks.


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## Done_Fishin (Oct 10, 2006)

The tank body should be earthed ... which should be that wire you show as to the body

one of your wires coming in should run from the LIVE side to one connection of the thermal cutout switch 

the other side of the thermal cutout switch should have a wire going to one side of the heater 

the other side of the heater should connect to Neutral

In order for the power light to illuminate, the power light has to be connected across LIVE & Neutral before the LIVE enters the thermal cutout.

In order for the Heater lamp to illuminate it must be connected between the "SWITCHED LIVE" & Neutral after the thermal cutout or the point where it is supply the LIVE to the water heater.

You need to ensure that the NEON you are using is capable of arcing or illuminating at your Mains AC voltage. If you (and don't do this!!!) place a NEON across a voltage supply without a resistor, it will arc and short circuit taking as much current as it can take .. the resistor is used as a current limiter after the Neon has arced ie the voltage across the NEON is higher than the operating voltage of the NEON.

I seem to remember that it's not unusual for a NEON to work with a 1MΩ current limiting resistor. 82 KΩ seems a little low to me but then do not know where you "found" the NEON and resistor.



LIVE ________1. thermostat 2. _____________3. Heater Element 4. ________ Neutral 



EARTH _____________________ Tank Body 




Connect NEON + RESISTOR across 1 & 4 for power indication


Connect NEON + RESISTOR across 2 OR 3 & 4 for heater indication


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## rajeshmarndi (Aug 24, 2009)

Thanks you very much for the reply.

For the indicator light it has wires at G&H and C& D only.

Now, the heater is not working at all. It showing no current at C, sometimes it show but for few moments only, I suspect the temp regulator set to low as I have tempered it many times while removing & fitting the cover. I corrected but now its showing no current at all.

I had to call the service center, lets see.


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## Done_Fishin (Oct 10, 2006)

Good luck .. and let us know the outcome


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## Kefali (Nov 11, 2012)

The resistor used with a neon that I looked at some years ago was 120K. However, I don't know the striking voltage of the neon. The mains voltage was 240v.

An important point is the voltage rating of the resistor. Most small resistors are rated at only 100v. The ones I use are metal film type and rated at 350v and 0.75 Watt.


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