avid_leaner88
Member
- Location
- San Jose
- Occupation
- Product designer
Hi folk, I am new and hope this is an appropriate question here.
I am designing a contraption that can detect current through a nema 1030 or nema 1430 receptacle.
The appliance plugged into these receptacles typically is a dryer, but I hope principle applies to any appliance.
I have noticed that some newer dryers, when running in power saving/cooling phase, would put load on only 1 of the hots. E.g. 9 amps on one hot, 0 amps on the other.
It becomes a crab shoot if I want to detect current using a hot wire, cause the dryer maybe putting load on the other hot that I am not measuring. Or I would need to measure current on both hots which adds to complexity.
However is it possible to detect the current on the neutral wire? In theory, current should be going through the same(shared) neutral wire no matter which hot has a load on it. I put that to the test, and saw that indeed there is current on the neutral wire when either hots has a load AND when both hots have loads, but it is only 5 amps (via a clamp meter), when I know the load on the hot wires are between 9 to 22 amps.
So my questions are
1. How come only 5 amps is measured when I think there should be more current running through the neutral?
2. Is it reliable to use Neutral as a method for current detection in a 240v circuit?
Thanks!
I am designing a contraption that can detect current through a nema 1030 or nema 1430 receptacle.
The appliance plugged into these receptacles typically is a dryer, but I hope principle applies to any appliance.
I have noticed that some newer dryers, when running in power saving/cooling phase, would put load on only 1 of the hots. E.g. 9 amps on one hot, 0 amps on the other.
It becomes a crab shoot if I want to detect current using a hot wire, cause the dryer maybe putting load on the other hot that I am not measuring. Or I would need to measure current on both hots which adds to complexity.
However is it possible to detect the current on the neutral wire? In theory, current should be going through the same(shared) neutral wire no matter which hot has a load on it. I put that to the test, and saw that indeed there is current on the neutral wire when either hots has a load AND when both hots have loads, but it is only 5 amps (via a clamp meter), when I know the load on the hot wires are between 9 to 22 amps.
So my questions are
1. How come only 5 amps is measured when I think there should be more current running through the neutral?
2. Is it reliable to use Neutral as a method for current detection in a 240v circuit?
Thanks!