Why does 240v not need a neutral

I have two appliances: one is old dryer which does not have a neutral, only 3 wires, black, red, and green; another one is a new oven which have 4 wire 30amp v. I want to know it is very important to have the neutral. I know it is in v. Can anyone help me with it? Stratmando Posts: 11,, Reputation: Ground is NOT to carry current except during a fault. New Construction and remodel require 4 wires. If just changing an appliance, it is not required. Mar 5, , PM. Using the NEC as a reference point.

Between the years and you were allowed ground the frames of appliances via the Neutral Grounded conductor. After , you were required to use a four wire circuit and the frames could only be grounded to the equipment grounding conductor. So, if your home was built prior to , you are allowed Grandfathered to continue the practice of grounding the frames of appliances to the Neutral. However, if the appliance you are using requires a four wire feed, then you must run an entire new circuit from the panel to the appliance outlet.

Older appliances might not have needed a neutral. Case in point, a simple water heater. A water requires only volts. If however, the appliance requires the use of volts , say for control panel circuits, then neutral would be required.

So after , a green grounding wire must be used for grounding the frames of the appliances. But what is the neutral is for if the four wire feed is needed for a v? This is getting confusing. WHERE is this green wire you speak of? NOT a "v" appliance. These definitely require a neutral.

Really, I talked to someone from an appliance store here. He said I needed four and v. But I am not very sure what in general a neutral is for in a v where there are three service entrance condutors, two hot wires and one white wire. I know a neutral is a return in a v. But how about in v? Okay, back to basic electricity.

Electricity that comes into your home from the power company is a "single phase" source. If you were to draw a vertical line and split it in the middle you would have two poles top to bottom that are volts apart. The line splitting the middle would be exactly volts apart from both of the poles. So if you were to measure from the middle line to the top, you would have volts AC.

If a device needs both V and V, then two ungrounded hot conductors and one grounded neutral conductor must be used. If you connect a load between the two ungrounded legs of the circuit, you can see how you have a complete circuit through the coil. If you connect a load between one of the ungrounded conductors, and the grounded neutral conductor. You can also get a complete circuit, though it's only through half of the coil. Electrical current needs a path in order to work. A neutral provides a path in volt circuits.

The current flows toward the load during the positive cycle and flows away from the load during the negative cycle.

Originally posted by Boscodog: Hi guys! Joined: Oct Anaheim, CA. This item is very simple. A single phase transformer, such as the ones commonly used for Residential areas, is nothing more than a volt 2 wire secondary, with a center tap. The center tap is where the "Neutral" conductor is connected [and is the first point of earth grounding].

A 3 wire DC system works exactly the same way, except there is no transformer. The center tap is between two batteries [or cells] wired in series. Center tapped secondaries can also be from split coil transformers.

In this case, it is tapped imto the X2 - X3 jumper. It works exactly the same way. There is an extensive discussion on this stuff in this forum, dating back around September, Look for an Archived thread named something like "How would you describe a neutral".

Note: The grounded common conductor on a 3 phase 4 wire Wye system doesn't always work the same as the 1 phase 3 wire grounded neutral conductor.

It very rarely carries unbalanced current levels. Thanks to all for the prompt replies! I have to admit I still don't quite 'get' it, but I will I'll be popping in every now and then. Thanks again. Originally posted by Mike: Electrical current needs a path in order to work. Here it is by God So which one is it? It can't do both No wonder I'm confused. I just read that stuff by Bill Beaty and discovered that I have just about every misconception known to man!

My brain is feeling torqued right now. Guess I throw-out most of what I learned in trade school about electical theory after reading Mr. Beatty's "misconceptions about electricity. NY, USA. Bill Addiss. I'm starting one titled How does Electricity flow? Moderated by dougwells , electure , gfretwell , HotLine1 , Scott35 , Trumpy.

Posts: 70 Joined: January