View Full Version : Defective double pole breaker?


crf_kdx
12-30-2012, 09:04 PM
Good day!

My heat pump has a 60AMP double pole breaker feeding it. Testing with a multimeter I get 125ish volts from each of the two poles to the ground bus but I show almost zero volts, rather than 250ish, between the two poles. Defective breaker, right?

((In case it matters, the box is an Eaton and the house is just 3 years old.))

Thanks in advance.

2LTim
12-30-2012, 09:12 PM
What do you get across your Main Breaker coming into the panel?

crf_kdx
12-30-2012, 09:17 PM
250ish across the main breaker as well as all the other double pole breakers (range, dryer, etc).

Delta74
12-30-2012, 09:25 PM
dont know the panel that well, so just a guess here, does the 2 pole breaker span BOTH sides of the bus?call it A and B, Black and red wire, whatever, I know the federal Pioneer panels you could stuff a double pole into a single leg, each side reads 120V but your not getting the full proper 240. as both sides of the breaker are in phase and not giving you a true 240 out.

pictures?

mllester
12-30-2012, 09:33 PM
Definitely something is wrong. Like Delta said, the line side of a 240v breaker has to connect to both of the buss bars in the panel. Your readings indicate both legs are connected to the same buss. Has anything changed since it last worked?

crf_kdx
12-30-2012, 09:35 PM
Looking at the open spaces it appears the connections alternate back and forth between the two hot buses. So my best guess is the furnace should be getting 250ish volts via the 60A breaker.

2LTim
12-30-2012, 09:36 PM
You must be having trouble with the heat pump, why else look at the voltages? I would turn off and then reset the heatpump breaker and recheck the volts out. It is possible (although rare) for only one side of a double breaker to trip without taking the other side out. What you are seeing with your volt meter is one leg of the 220 going out to the H/P then returning on the other (dead) leg. If you check voltages from your main to the output side of your H/P breaker, you will get 220V from one side of the main to both sides of the H/P breaker, and 0V to both from the other side of the main.

sparky36000
12-30-2012, 09:45 PM
If one pole of the breaker is not closed, you will read 120V from both sides of the breaker if it is reading thru a control transformer or motor on the heat pump. Disconnect wiring from the breaker and turn it on and re-check phase to phase and phase to ground. One pole should read 0V if it's not closing. It may also work to "exercise" the breaker if it's not closing on one pole. I would replace it even if you can get it to close though.

crf_kdx
12-30-2012, 09:45 PM
A bit more background may be in order. I lost power in the master bath lights and one of the gfci outlets wouldn't reset. I replaced the gfci outlet with a like outlet. Still no power to the replaced plug or the lights. So I went thru the breaker box resetting the breakers one at a time. Even though the douple poles likely weren't my power issue in the bath I reset them anyway. While testing the voltage on the single pole breakers I checked the double poles just for the heck of it. That's when I discovered the quirk with the breaker for the heat. To my knowledge the furnace was working prior to me resetting the all the breakers. Sigh ...

2LTim
12-30-2012, 09:47 PM
Is it still working?

sparky36000
12-30-2012, 09:48 PM
2LTim beat me to the post, what he said is basically what I said.You must be having trouble with the heat pump, why else look at the voltages? I would turn off and then reset the heatpump breaker and recheck the volts out. It is possible (although rare) for only one side of a double breaker to trip without taking the other side out. What you are seeing with your volt meter is one leg of the 220 going out to the H/P then returning on the other (dead) leg. If you check voltages from your main to the output side of your H/P breaker, you will get 220V from one side of the main to both sides of the H/P breaker, and 0V to both from the other side of the main.

sparky36000
12-30-2012, 09:51 PM
Hmmmm.... sounds like you lost a phase coming to the building, or in the panel. A bit more background may be in order. I lost power in the master bath lights and one of the gfci outlets wouldn't reset. I replaced the gfci outlet with a like outlet. Still no power to the replaced plug or the lights. So I went thru the breaker box resetting the breakers one at a time. Even though the douple poles likely weren't my power issue in the bath I reset them anyway. While testing the voltage on the single pole breakers I checked the double poles just for the heck of it. That's when I discovered the quirk with the breaker for the heat. To my knowledge the furnace was working prior to me resetting the all the breakers. Sigh ...

crf_kdx
12-30-2012, 10:00 PM
... If you check voltages from your main to the output side of your H/P breaker, you will get 220V from one side of the main to both sides of the H/P breaker, and 0V to both from the other side of the main.

This is the situation! So, what does that mean?

sparky36000
12-30-2012, 10:04 PM
This is the situation! So, what does that mean?

Are you getting 240V across the main?

crf_kdx
12-30-2012, 10:07 PM
Yes sir - 240ish on both the input and output sides of the main.

2LTim
12-30-2012, 10:08 PM
One side of your H/P breaker is dead. Turn it off, disconnect bothe wires going to your heat pump, turn the breaker back on and check output voltages. this will tell you which leg is dead. Seeing that it is after 9pm central time, it's too late to make a tirip to the big box to get another breaker. I would probably pull the breaker and test the lugs to make sure they are live, then repurpose the Range or A/C breaker to the Heat Pump circuit to get me thru the night.

RECox286
12-30-2012, 10:08 PM
Check out the output of all your breakers, single and 2 pole.

You may have lost one leg of 120. Very common around here where

the salt air gets into the crimps that connect the triplex to your

service entrance cable. Other than that, back feed thru one side of

the 60A bkr from the equipment, and only 120 available showing on

both sides of the bad breaker.

Uncle Bob

2LTim
12-30-2012, 10:10 PM
You may try "Exercising" the breaker to see if it comes back to life. Any way you look at it, this breaker needs to be replaced!

sparky36000
12-30-2012, 10:12 PM
Yup, what he said. Back to sounding like a bad 60A breaker. One side of your H/P breaker is dead. Turn it off, disconnect bothe wires going to your heat pump, turn the breaker back on and check output voltages. this will tell you which leg is dead. Seeing that it is after 9pm central time, it's too late to make a tirip to the big box to get another breaker. I would probably pull the breaker and test the lugs to make sure they are live, then repurpose the Range or A/C breaker to the Heat Pump circuit to get me thru the night.

crf_kdx
12-30-2012, 10:29 PM
Gentlemen - thank you all for your kind, helpful and timely assistance on a Sunday night. I greatly appreciate it! I'll replace the breaker when the local big box stores open in the morning.

((2LTim - I grew up outside Cedar Rapids and I lived in Cedar Falls, Waterloo, Fort Dodge and Ames prior to relocating in KY.))

sparky36000
12-30-2012, 10:35 PM
:thumbup:

2LTim
12-30-2012, 10:43 PM
There is always plenty of room if you decide to return!!!!