110VAC from 220VAC How to?

dieselscout80 · Apr 10, 2012

Here is a pic of how my well pressure switch is wired.

Before we bought this place there was a 110VAC circuit pulled from the switch out to a old pig pen, but it was disconnected before we got the place. The wire going to the pen, the outlet, light and light switch that the previous ower installed are still there. I need to use some electrical tools there for a few days (skil saw ect).

The circuit to the well pump is 220VAC the wire leading to the pressure switch has a black and white wires and a ground.

How can I connect to my well pressure switch to get a 110VAC circuit (wire going to the pen has 3 wires 1 black, 1 White and a Ground)?

I asked in this thread, but I never really got a warm fuzzy about it.
http://www.tractorbynet.com/forums/projects/221759-110v-off-220v-circuit.html

I just noticed the ground wire from the house to the pump is not connected need to fix that ASAP.

dieselscout80 · Apr 10, 2012

This link gives me the most confidence that it can't be done.
http://www.tractorbynet.com/forums/projects/221759-110v-off-220v-circuit-2.html#post2537727

oldnslo · Apr 10, 2012

You would need a neutral wire to get 110 VAC from 220 VAC. On your 220 VAC circuit are there 3 wires or 2 wires?

If only two wires you can not safely get 110 VAC.

If three wires one of the wires should be a neutral. If you have a Volt meter check voltages across the three wires. between two of the wires you should read 220 VAC these are the two hot leads. Between one of these hot leads and the third wire yo should read 110 VAC. That would indicate the third wire is a neutral wire. Using these two leads will provide 110 VAC.

I would not run a skil saw and your well at the same time since you would have uneven loads across the hot legs which may cause your breaker to trip or potentially damage your well pump.

dieselscout80 · Apr 10, 2012

oldnslo said:
You would need a neutral wire to get 110 VAC from 220 VAC. On your 220 VAC circuit are there 3 wires or 2 wires?

If only two wires you can not safely get 110 VAC.

If three wires one of the wires should be a neutral. If you have a Volt meter check voltages across the three wires. between two of the wires you should read 220 VAC these are the two hot leads. Between one of these hot leads and the third wire yo should read 110 VAC. That would indicate the third wire is a neutral wire. Using these two leads will provide 110 VAC.

I would not run a skil saw and your well at the same time since you would have uneven loads across the hot legs which may cause your breaker to trip or potentially damage your well pump.

I had not thought of the difference in the load on the two legs of the 220VAC circuit and the possible effect on the pump. I may just run it to the house and tie into another circuit.

SPYDERLK · Apr 10, 2012

dieselscout80 said:
Here is a pic of how my well pressure switch is wired.

Before we bought this place there was a 110VAC circuit pulled from the switch out to a old pig pen, but it was disconnected before we got the place. The wire going to the pen, the outlet, light and light switch that the previous ower installed are still there. I need to use some electrical tools there for a few days (skil saw ect).

The circuit to the well pump is 220VAC the wire leading to the pressure switch has a black and white wires and a ground.

How can I connect to my well pressure switch to get a 110VAC circuit (wire going to the pen has 3 wires 1 black, 1 White and a Ground)?

I asked in this thread, but I never really got a warm fuzzy about it.
http://www.tractorbynet.com/forums/projects/221759-110v-off-220v-circuit.html

I just noticed the ground wire from the house to the pump is not connected need to fix that ASAP.

Your pump service was not set up to make a 120 circuit available. ... Yet there is 120 avail between either of the hots and the ground wire. For 120 availability done right, the service line to the well would have been 4wires [3 wires- H,H,N, and a ground wire]. Then, to get 120 safely yould go between one of the H and the Neutral. N and Ground are at the same potential [0] as they leave your house panel, but due to inherent resistance in all wire, as soon as current is drawn thru either at the well location that one will have a potential above 0. For instance, with 4 wires, you hook your saw from N to H and turn it on. The 10A or more it draws causes the total 120V available between NH at the well under no load condition, to split up between the tool and the conductors. You may lose as much as 5V in each line to the well, leaving 110 remaining across the running tool. In this case the loaded H to N measures 110 -- but N to G measures 5V because G is not carrying current and hence presents the true (0) potential from the house panel to well. B-B But if you have no N and use G for neutral it will act the same as N did and present 5V at the well when the tool is on. Since G is also connected to the well casing there will be a 5V charge on the casing as the tool runs. Not so bad but surely enuf to feel if your feet are wet [at earth 0] and your hand touches case "ground". A different story as you start the tool. High start surge will cause momentary high potential on case ground - maybe 15V. And then theres always the possibility that a break will occur somewhere in G. Then turning on the tool [trying to - it wont run] puts 120 at case ground

. So as you can see, dangerous conditions are possible using G as a current carrier. 4 wire prevents this risk.
larry

Arsavoie · Apr 10, 2012

Do any of you know the difference between 3 phase and single phase? You are not going to have three wires cause cause it's for a 240 v motor.
if you want 120v take one hot and a ground that makes 120 v . A neutral is a grounding conductor and a ground is a grounded conductor. Know the difference before you give advice.!

mjw357 · Apr 10, 2012

Rent or borrow a small gas generator. Don't electrocute yourself.

speedbump · Apr 10, 2012

I am in the pump business and will tell you that what your trying to do is not only non-code, but it's dangerous. If you look at the insulation on your wires in your picture, they have gotten real hot already. The insulation is burnt and peeling away. Adding more amperage draw to the already inadequate supply, is just asking for trouble.

There is a ground wire connected to the body of the switch. If you took one of the 115v leads and used the ground as a neutral, it would run your saw. However, I recommend doing something more conducive to not burning down your home.

chim · Apr 10, 2012

Arsavoie said:
Do any of you know the difference between 3 phase and single phase? You are not going to have three wires cause cause it's for a 240 v motor.
if you want 120v take one hot and a ground that makes 120 v . A neutral is a grounding conductor and a ground is a grounded conductor. Know the difference before you give advice.!

That's backwards. The Neutral is the GROUNDED conductor and the Ground is the GROUNDING conductor.

SPYDERLK · Apr 10, 2012

speedbump said:
I am in the pump business and will tell you that what your trying to do is not only non-code, but it's dangerous. If you look at the insulation on your wires in your picture, they have gotten real hot already. The insulation is burnt and peeling away. Adding more amperage draw to the already inadequate supply, is just asking for trouble.

There is a ground wire connected to the body of the switch. If you took one of the 115v leads and used the ground as a neutral, it would run your saw. However, I recommend doing something more conducive to not burning down your home.

That heating shown is probably from past loose or corroded connections. The wires look at least 14ga. Plenty at 240 for a pump. Connections must be clean and tight.
larry