How can i detect 230V (pump active)?

[ahhk]

Hi all,

i hope you have an idea. The situation: I have a water-bearing fireplace which is integrated into the heating system of my house. There is a temperature-sensor, which switches at 70°C so that the heatingpump gets 230V and starts

My challenge is now, to detect when the sensor closes and opens (pump on / off) without cutting the direct connection (the direct wire) between 230V, Sensor and Pump (legal requirement).

My first thought was to install a relay in parallel to the pump. But this draws 1W - a bit too much for me.

My question is now: How can i easily detect, when the pump is on and off? Any Ideas?

[mvdarend]

A non-invasive current sensor?

http://www.aliexpress.com/item/Free-Shipping-New-Non-invasive-0-100A-AC-Sensor-Split-Core-Current-Transformer-SCT-013-000/32280304935.html

[jkandasa]

@ahhk you can use something like "Electric Field Detector", example: http://forum.arduino.cc/index.php?topic=85752.0

[ahhk]

Hi,

sry guys, i withdraw my question. I just found a simple and unbelievable easy solution: 230v small signal lamp + LDR.

It could not be cheaper and easier.....LOL

Thx for your proposals!
Greetings

Andreas

[MikeF]

What's a 'small signal lamp', and how much power does it draw?

I'm looking for a similar solution - I want to monitor my central heating and hot water system. I've got a UK 'Y-plan' system, with a mid-position valve. One wire to the valve is energised (i.e., 230V) when heating is on, while another is energised when hot water is off.

[ahhk]

Hi,

something like this: http://www.ebay.com/itm/Signalleuchten-mit-Lampe-Max-230-V-Rot-transparent-RAFI-Inhalt-1-St-/400562275133?hash=item5d435f433d

On the arduino-side, just use an LDR (http://www.ebay.com/itm/20PCS-Photoresistor-LDR-CDS-5mm-Light-Dependent-Resistor-Sensor-GL5516-Arduino-/311050784623?hash=item486c124f6f)

The LDR triggers an interrupt and the arduino wakes up to send "on" or "off" signal ;)

Greetings

Andreas

[MikeF]

I'm trying to detect mains voltage as suggested above, using a miniature mains neon indicator and photodiode sensor module (digital output):
(http://www.ebay.co.uk/itm/301337737695?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT)
(http://www.ebay.co.uk/itm/161785822980?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT)

I'm using the MySensors Door / Windows / Button example sketch, however in serial monitor I'm getting rapidly alternating fail messages:

send: 1-1-0-0 s=3,c=1,t=16,pt=2,l=2,st=fail:0
send: 1-1-0-0 s=3,c=1,t=16,pt=2,l=2,st=fail:1
send: 1-1-0-0 s=3,c=1,t=16,pt=2,l=2,st=fail:0
send: 1-1-0-0 s=3,c=1,t=16,pt=2,l=2,st=fail:1
send: 1-1-0-0 s=3,c=1,t=16,pt=2,l=2,st=fail:0
send: 1-1-0-0 s=3,c=1,t=16,pt=2,l=2,st=fail:1

Is this because the input is changing at 50Hz? (it works OK on a battery-powered torch).

Is there anything I can do to overcome this?

[AWI]

@MikeF Just a guess.. I think a Neon - Photodiode combination is to fast. A LDR is a rather slow analog device which can be damped with a capacitor in parallel. You could try it with the photo diode and a 0.1 - 1.0 uF value. The fails are probably because the radio cannot keep up with the speed (50 Hz => one message each 10ms )

[MikeF]

Success! :smile: with 1.0uF across photodiode, although pot adjustment setting is quite sensitive. May try replacing photodiode with LDR.

Thanks!

[ahhk]

Hi,

or use a small bulb instead neon...should also work. But a cap in parallel is always a good idea for this.