There is an Electric panel which is placed near to air washer duct (provided for cooling purpose (made of Stainless steel)). When i passes my hand between Duct and panel i feel there is something happening (may be current is flowing due to thermal gradient).
I want to know what are the possibilities? If it is current then how can i measure it?
Thanks & Regards,
Anurag
If I understood fairly well, then fluid flow or Laminar flow is one way of modelling
https://en.wikipedia.org/wiki/Laminar_flow
https://www.comsol.com/multiphysics/navier-stokes-equations
With electronics and EMI , we have the human body model (R & C)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2763825/
I don't think this current is flowing due to the thermal gradient. It may be the capacitive coupling of the electric panel. The AC current can be conducted through the equivalent capacitor between you and the electric panel. You may measure it using a metal plate which is grounded.
There are several things you may consider. One, can you measure the voltage difference between some panel points and duct wall points? Second, may you ground one or both of them and notice any change in that measurements? Third, what do you feel after connecting them with a cooper wire? Fourth: Can you measure the temperature difference between both surfaces? Because what you feel may be just an air flow, not current flow.
If you want to measure electrical current through air, you can use grounded femto-ampere meter. We used for measuring negative air ion flux. It will take relatively high voltage DC to get electrical current to emit from sharp conductive objects through air.
For fluid flow rate of air you can use hot-wire anemometer,
Air is insulating material and it begins to conduct current at the onset of its breakdown. So, if the voltage between the panel and the duct wall is sufficiently high it can cause some ionization of the air gap and a current flow. As the panel contains AC sources, it is possible that there will be capacitive currents flowing in the air gap between the panel and the duct especially if the duct is grounded. When you introduce your hand you establish screening effect between the panel and duct. You did not describe precisely what do you felt whether it is a light electric shock or what else?
It can so that you are electrically charged and when you approach a metal surface a discharge process takes place and you may sense electrical shock and if this is at night you observe light sparks. This is a very well known phenomenon an happens in dry and hot climates.
I think the second scenario is more probable.
I think the suggestions by the colleagues above will help you to analyse the problem and location of the cause of your sensation.
I think it is required that you describe what is happening with you in more details and what is the electrical relation between the panel and the duct.
Best wishes
Arc horn runner are used to extinguish arc when circuit is opened, with sufficient distance air would provide good insulation. Break down cold be occurred depending on existing impurity and moistures, hence leakage current would be more, for same distance in urban area than the rural...
Dear Fernando Sir,
I measured Voltage difference b/w duct and panel it is 4.6 mV. and after grounding Duct 1.2 mV is there. I think this is quite less voltage.
But, just behind the panel section there is furnace i.e. running on 780 degree C and there is quenching section. So, i want to know what are the possible reason of feeling (may be) like a small shock.
Thanks.
One possibilty is that you have an "intersystem grounding" issue. That is, the ground for the air washer is not the same ground connected to the electric panel. Duct and panel build up a capacitor, some charge will accumulate over the "plates". When you put your hand between the "plates", you modify the dielectric media between plates and there is some «displacement current» at your hand because of charge change over the "plates". The voltage difference you mention is quite small to be "sensed" by hand, however, big area plates and short distance in between can make a big capacitance. Further, your body itself may be at another grounding level.
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