Riello 40 coil ( p/n 3002279 ) - voltage?

[Baltezer]

Hi,
Could someone please tell me what voltage this solenoid should get from the control box?
I read that a Riello coil only needs 3V during run (but 29V at ignition), but I'm not sure if this applies to the 3002279 also.
This coil is 1.5 kOhm, so with 3V it would only draw 2 milliamps or 6 milliwatts of electrical power... almost the same as nothing.

 

[Terrywookfit]

29 V DC at ignition, Switching to 3 Volts during run. The coil has two tappings; the first to use the full coil potential to CLOSE the valve, then reduced voltage to hold it there.
(Note: The RDB burner coil has only 2 wires, the coil winding voltage from control box gives 30 V DC and 3 V DC on run).

 

[Baltezer]

Hi Terry,
Thank you for your answer. I found that also on the Riello website, but it wasn't clear to me if this applies to the Riello 40 valve (p/n 3002279) as well.
But I would like to know how it works. I don't understand their explanation.
-First thing I don't get is that 29V closes the valve at ignition. How will closing the valve (instead of opening) allow oil flow to the burner?
-Second thing I don't understand is that 3V is enough to do anything. With the 1.5 kOhm coil (I measured on part 3002279), you would have only 6 milliwatts of power at 3V...
I'm doing some research on the magnetic fields of burner coils and have a number of coils from different brands on my desk.
I just don't know how much volts to apply. With 3 volts it seems to do nothing...
I hope someone can help me with this odd question
Thanks

 

[Terrywookfit]

On start up there is a wash pressure around the pump.
The solenoid is on the return so closing it causes a pressure rise, Regulated by pressure adjuster.
Once closed it takes very little to hold it there.
What are you trying to do?

 

[Baltezer]

Thanks again Terry,
Thank you for your clarification. I get it now... it was not really explained in the burner technician course that I took. But in my book I found a normally opened (NO) valve technical drawing, so that must be a Riello drawing
I have a pump and coil for the Riello 40, but I don't have the complete burner with control box etc. Therefore my question.
The company I work for makes WiFi connected oil meters where you can input the fixed oil flow rate of your burner. The device senses the magnetic field of the coil and then starts counting. It works fantastic with Danfoss and Suntec valves.
We always stated that our meter is not compatible with Riello coils, but people keep asking. Therefore we sometimes make small series of our device that connects to B4 of the 7-pole socket. This works perfectly also, but the simple sensor solution would be much prettier.
We have a new sensor that detects the magnetic field of the Riello 3002279 coil when 12V or more is applied. But when only 3V is applied it doesn't work... Logic, there really is nothing to measure with 3V. Therefore I wanted to check if it is really only 3V (as I don't have the control box).

Thanks again!

 

[Agile]

Why do they use such an odd way to monitor the oil flow?

Whats wrong with a magnetic turbine ? Or are they less accurate due to the differing viscosity as temps vary?