I have an older pool heatpump that needs 220v 25amps. I have 10/2 wiring to a 25 amp breaker in my box. I test 120v on each (black & white) to the ground wire. Nothing seems to work. I can bypass to get the fan to work, but it barely spins. Seems like I'm working on 1/2 power. I'm obviously no electrician, but do I need to have 220v coming out of my wire, or is it meant to be the 110v X 2 ? I have the groung attached to the metal casing of the heatpump unit. I seem to have the 110v all over the place (before and after each switch, thermostat, etc) but no where can I measure 220v. The connection in the unit has a junction piont for 2 wires. What am I doing wrong?

At panel, you should have 240 volts between the 2 wires on your breaker.
It will measure 120 volts between either hot and neutral or ground. However you should measure 240 volts, if you measure zero volts, you are on same phase. Problem may be beyond panel. Need to get 240 between both phases.

Thanks for your quick answer. So let me ask this very simply. When I measure voltage from black to ground I get 120v. From White to ground I get 120v. Are you saying I should have a reading when I measure black to white? I get nothing. What could be the problem? Wrong breaker ? Problemin the panel ? Or problem with me..
Thanks for the help

You should have a two pole breaker in the panel, when you check the voltage across the two wires at the breaker you should have 220 volt, if not then perhaps one side of the breaker is tripped, turn it off and push it to the off position to reset it. Check other two pole breakers in the panel to determine that you in fact have 220 volts in the panel.
Do you have both wires (black and white) connected to the breaker?

There is a problem somewhere. Basically there are 4 connections in a panel. They are L1, L2, N and ground. Ground and N are connected at the panel (assuming one panel) and ground goes to a ground rod.

L1 relative to (N or G) is 180 degrees out of phase from L2 to (N or G). This is why when you measure the voltage from L1 to (G or N) and L2 to (G or N) you get 120 Volts. When you measure between L1 and L2 you should get the sum of (L1 to (G or N)) and L2 to (G or N)).

From black to white, you should have 220 volts. Since you have 0, there are two connections to L1 or two connections to L2.

Why?

Go back to the panel and preform the same set of measurements. Something is amis. The breaker should be ganged together and take up two slots.

From what I read recently on this forum, you could have the wrong breaker installed. WHat you have is a breaker that gives you two separate 120 Volt circuits rated the current rating of the breaker instead of one 220 Volt circuit.

The required breaker should take up two slots in the panel. If it takes up 1, you definitely have the wrong breaker.

You likely have a tandem breaker (1 slot)and not a double pole breaker (2 slots). These tend to be used when there are not enough slots in a panel.

Fix. A lot of re-arranging and/or a sub-panel. That's another discussion and my first sentence would not be correct for the sub-panel.

Excellent answers. I would hope this has been fixed by now, what was the outcome? Feedback helps everyone.

I moved the double breaker one slot. Apparently with a Stab-loc panel, it can be finnicky that way. Anyhow, I moved over 1 slot right beside another 220 breaker, and I got my good 220 power. The only problem now is the low freon. Seems like I need about 20 lbs!! Anyone know a cheap way to fill R-22?