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Thread: Quick circuit breaker question for sparkies

  1. #1
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    Quick circuit breaker question for sparkies

    This is a picture of two sets of two circuit breakers for one of my 5-ton HVAC units. It's the top to breakers on the left and right that I'm referring to.
    Left Circuit Breaker Panel - Cropped.jpg

    I'm assuming the unit is 230V, and the two top breakers are tandem, so my understanding is that it's a 230V 45amp load for the left condenser, and the same for the right Air Handler, but there is no plastic handle tie connector between the two of them. Does this appear to be true, and should I be picking up a handle tie like this one to tie them back together:
    https://www.amazon.com/Eaton-cutler-...y&sr=8-1-fkmr0
    I dream of a better tomorrow - where chickens can cross roads and not have their motives questioned

    Two hunters are hunting in the forest. One suddenly clutches his chest in pain and collapses. The other hunter calls 911 on his cellphone. "What is the emergency?" "Operator, my friend just collapsed on the ground. I think he is dead! What must I do?" "OK, first of all, make sure he is really dead." "OK then…" BANG! "Now what?"

  2. #2
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    Can't see the pic, but at 5 tons, the air handler blower motor could still be 120V, maybe it's a separate circuit from the controls. But, if the blower motor is indeed 240V, then by all means the circuit breaker feeding it should be a bonded double.
    Jason

    "Don't get stuck on stupid." --Lt. Gen. Russel Honore


  3. #3
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    Take the cover off the panel, and look to see if each breaker has a black wire on it, or if one is black, and the other is White, or Red.

  4. #4
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    Could be two circuits...one for the interior unit and one for the exterior unit. That's how both of my HVAC systems are setup.
    --

    The most expensive tool is the one you buy "cheaply" and often...

  5. #5
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    For five tons I would guess 25amps at 240V. I would guess your compressor is 120V? But I would expect any compressor over 1.5 tons to be 240 volt.
    That breaker could be a double with only one handle I suppose.
    BTW does your utility offer a discount if they install a load controller on your ac? At 5 tons I would expect a 10-20 dollars a month off your bill.
    Bill D

  6. #6
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    Yea ya really gotta get the cover off that panel to know/see for sure. Be careful though man, make sure you have that main off before you touch ANYTHING. In fact, Id suggest you turn that main off before you take that cover off too. Better safe than sorry. And keep in mind even with the main off, unless youve called the electrical company and had them come out and kill the main to your house, that main is still live, exposed and will most definitely shock you out of this world if you happen to come in contact with it.
    If at first you don't succeed, redefine success!

  7. #7
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    Quote Originally Posted by Ben Rivel View Post
    Yea ya really gotta get the cover off that panel to know/see for sure. Be careful though man, make sure you have that main off before you touch ANYTHING. In fact, Id suggest you turn that main off before you take that cover off too. Better safe than sorry. And keep in mind even with the main off, unless youve called the electrical company and had them come out and kill the main to your house, that main is still live, exposed and will most definitely shock you out of this world if you happen to come in contact with it.
    Not gonna open the cover. I don’t like electricity that much.

    Here’s a closeup of one of the breaker pairs. I think these must be just missing that bar. The second breaker says “Common trip” on it. No other breakers say that. Does that indicate that it’s a tandem breaker with the top one, 230V pair?

    4C26E1EB-32EE-42B9-ADF7-3BE2B6377CBE.jpg
    I dream of a better tomorrow - where chickens can cross roads and not have their motives questioned

    Two hunters are hunting in the forest. One suddenly clutches his chest in pain and collapses. The other hunter calls 911 on his cellphone. "What is the emergency?" "Operator, my friend just collapsed on the ground. I think he is dead! What must I do?" "OK, first of all, make sure he is really dead." "OK then…" BANG! "Now what?"

  8. #8
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    Quote Originally Posted by Alan Lightstone View Post
    Not gonna open the cover. I don’t like electricity that much.

    Here’s a closeup of one of the breaker pairs. I think these must be just missing that bar. The second breaker says “Common trip” on it. No other breakers say that. Does that indicate that it’s a tandem breaker with the top one, 230V pair?

    4C26E1EB-32EE-42B9-ADF7-3BE2B6377CBE.jpg
    Page 17 here: LINK
    And sold pretty much everywhere: LINK
    Looks to me like it can be used as either a 120V or 240V breaker.
    If at first you don't succeed, redefine success!

  9. #9
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    It's really no big deal taking the cover off, and no need to stick your hands in there. Hold the cover in place with one hand, as you back out the last screw, then take both hands, and pull the cover straight off. Look to see wire colors connected to those breakers.

    To put cover back on, have one or two screws in one hand, put cover back in place, holding it with one hand after it's in place, and replace the screws. It can only go back on in one position, since it has to fit around the breakers like you see it, so it's not really a balancing act.

  10. #10
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    In what is known as a split phase system (your house 240/120 volt power) you should never use two single pole breakers. Always use a two pole breaker that has the tie bar connecting the two handles together. You cannot (when I last checked) buy this bar separately from any breaker manufacturer. You need to buy the correct two pole breaker with the handles tied together. This is a safety device that forces both breakers off should there be an overload on just one of them. Without this, one breaker could stay on and even though the 240 volt appliance is no longer running, it would still have power being supplied to it through the one un-tripped breaker. It could prove deadly for someone who thinks the power is off because the appliance doesn't operate and begins servicing it. The same is true for three phase systems where all three breakers need the trip bar across all three handles, so that an overload on any one phase will turn all three circuit breakers off. It's a code requirement for a reason.

    Charley

  11. #11
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    Quote Originally Posted by Alan Lightstone View Post
    Not gonna open the cover. I don’t like electricity that much.
    Get your brother-in-law to open it. Seriously, you are wise to stay on the outside of the box if you lack experience. Ask around - you probably know someone who can not only open the box but has enough knowledge and experience to analyze what's inside and determine if you need to change anything. It's a 5-minute task. You can watch and learn a bit.

  12. #12
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    Quote Originally Posted by Charles Lent View Post
    In what is known as a split phase system (your house 240/120 volt power) you should never use two single pole breakers. Always use a two pole breaker that has the tie bar connecting the two handles together. You cannot (when I last checked) buy this bar separately from any breaker manufacturer. You need to buy the correct two pole breaker with the handles tied together. This is a safety device that forces both breakers off should there be an overload on just one of them. Without this, one breaker could stay on and even though the 240 volt appliance is no longer running, it would still have power being supplied to it through the one un-tripped breaker. It could prove deadly for someone who thinks the power is off because the appliance doesn't operate and begins servicing it. The same is true for three phase systems where all three breakers need the trip bar across all three handles, so that an overload on any one phase will turn all three circuit breakers off. It's a code requirement for a reason.

    Charley
    ^+1^

    Top/Left x2 sure look like they need to have a mechanical interlock. It's dangerous as-is. Alan, If your're not going to open it, get an electrician to verify/replace.
    Molann an obair an saor.

  13. #13
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    Back in the day, you would just drop a nail in the top hole to tie the breakers together.
    NOW you tell me...

  14. #14
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    Alan
    Please don't indiscriminately install that breaker tie you link to.
    I'm assuming that your system was installed and inspected at the time of installation, so you should have some confidence that the electrical was installed per the prevailing code at the time.
    A two pole 240vac breaker trips internally. The external mechanical tie between the two switches is for mechanical isolation of the circuit. Yes, it will trip both sides mechanically if one side trips, but not the other, but in that case you have a defective breaker.
    There are external ties for 120 vac breakers, but they're not used so much for electrical protection, as for system protection logic. For instance you may have a blower/fan that work in concert with a pump, or an igniter all on 120vac circuit, that may be required by code to be on dedicated breakers. Any failure in one, would make it desirable to shut off the other so that a system will not operate incorrectly for extended lengths of time.
    Call in the folks that installed your system, if you installed it, or call in an HVAC company that you trust to look at the electrical setup in your service panel. You can't just look at wire colors and have 100% certainty, unless you can read the entire panel. Which it doesn't sound as if you can. You really need to know how it was installed, before you alter the electrical supply.
    "The first thing you need to know, will likely be the last thing you learn." (Unknown)

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    Am I the only one wondering about the elevator?

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