Breaker and wire size for pool heat pump - MCA, wire and breaker size.
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Bluebinky
Member
I think you are missing the point altogether. The problem with the lights was a that every aspect of the wiring between the pole and the light bulb while being code-compliant when installed did not cut it as a system, including the #14 wire shared by the lights and the fridge. Codes change over time (including the NEC). Did I say there was a safety issue? No. I do like my lights to stay on continuously, so I upgraded a marginally serviceable installation to one that is first rate. Over-built? NO. You can use #16 or whatever on a 20A circuit for an appliance cord, but not inside the walls. HJ pointed out similar logic should be applied when putting #10 on a 60A breaker, and I agree.
My truck is an 86 F350. Not so many safety features -- couldn't be sold as new today -- it wouldn't cut it any more. While it might crush yours in a crash, you'd probably walk away and I wouldn't. Some people understand that sort of thing when building stuff. Correct/superior application of materials is not the same as over-building with excessive materials.
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ActionDave
Electrician
A fine example of this would be using the nameplate info on an A/C unit to size the conductors and breaker.
ActionDave
Electrician
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JWelectric
Electrical Contractor/Instructor
Any motor that is bigger than one eight horse power is required to be protected by thermal overload. An outside unit will have this overload built in the unit.
Thermal overload protects the circuit and motor from damage due to overload. The fuse and or circuit breaker protects the circuit from short circuit and ground fault.
The fuse or circuit breaker will need to be big enough to let the motor start. As a general rule of thumb any motor will draw six times its running load current in order to cause the shaft to move.
An example is a 5 horse power 240 volt single phase motor has a running load amps of 28 but in order to get the motor started it will have an inrush current of 168 amps. Although the motor will only need a #10 conductor it will need a 50 amp time delay fuse or a 70 amp inverse time breaker. The thermal overload will be set at 35 amps which is the amount of current that a #10 will safely carry.
Install this motor where an instantaneous trip is needed and a 225 amp breaker can be safely used on this same #10 conductor. Remember the overload will remain at 125% the running load amps of the motor no matter the fuse or circuit breaker used.
When it comes to the thought that bigger is better where do we stop? Experience is a great teacher, trying to install a #6 conductor under a 30 amp breaker will lead one to trim away some strands so it will fit the terminal. Now if the strands are trimmed away just what size it the conductor when all this trimming is done. One thing is for sure, once the trimming starts’ failing an inspection is for sure.
I think I will replace all my circuits with 2000 KCMIL conductors so the dimming of the lights will go away when the power grid sees a surge. Do they make a conductor larger than 2000 KCMIL that I can use to stop the dimming of my lights? My refrigerator draws 6.5 amps maybe it should have paralleled conductors, then again maybe there is no way to stop the dimming of my lights during an ice storm where trees are falling across the power lines.
Something to think about when dealing with voltage drop and all the hype revolving around the idea. During off peak hours such as 2AM my voltage can be as high as 132 volts but my brother who lives beside a mobile home park during peak hours 6PM can see as little as 110 volts. I think that the utility is varying more than the 5% mentioned above.
Edited to add;
The conductor just like the running overload will be sized at 125% of the amps of the motor
Thermal overload protects the circuit and motor from damage due to overload. The fuse and or circuit breaker protects the circuit from short circuit and ground fault.
The fuse or circuit breaker will need to be big enough to let the motor start. As a general rule of thumb any motor will draw six times its running load current in order to cause the shaft to move.
An example is a 5 horse power 240 volt single phase motor has a running load amps of 28 but in order to get the motor started it will have an inrush current of 168 amps. Although the motor will only need a #10 conductor it will need a 50 amp time delay fuse or a 70 amp inverse time breaker. The thermal overload will be set at 35 amps which is the amount of current that a #10 will safely carry.
Install this motor where an instantaneous trip is needed and a 225 amp breaker can be safely used on this same #10 conductor. Remember the overload will remain at 125% the running load amps of the motor no matter the fuse or circuit breaker used.
When it comes to the thought that bigger is better where do we stop? Experience is a great teacher, trying to install a #6 conductor under a 30 amp breaker will lead one to trim away some strands so it will fit the terminal. Now if the strands are trimmed away just what size it the conductor when all this trimming is done. One thing is for sure, once the trimming starts’ failing an inspection is for sure.
I think I will replace all my circuits with 2000 KCMIL conductors so the dimming of the lights will go away when the power grid sees a surge. Do they make a conductor larger than 2000 KCMIL that I can use to stop the dimming of my lights? My refrigerator draws 6.5 amps maybe it should have paralleled conductors, then again maybe there is no way to stop the dimming of my lights during an ice storm where trees are falling across the power lines.
Something to think about when dealing with voltage drop and all the hype revolving around the idea. During off peak hours such as 2AM my voltage can be as high as 132 volts but my brother who lives beside a mobile home park during peak hours 6PM can see as little as 110 volts. I think that the utility is varying more than the 5% mentioned above.
Edited to add;
The conductor just like the running overload will be sized at 125% of the amps of the motor
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DonL
Jack of all trades Master of one
A good peak and hold meter is nice, to really see the requirements of a appliance.
I use a meter that you can connect to a computer and plot usage over time.
I guess I am a bit spoiled, because I have a PC scope for getting serious and making logs.
From what I can tell, the power company does a lot of switching here.
The power is either On or Off, and when it is on, it is within 5%.
It is about normal to loose power for less than a second, but it can be off for more cycles than most electronics can recover from. A compressor may have near locked rotor amps, and TVs can make you think they are broke.
I use care when playing with electricity.
I use a meter that you can connect to a computer and plot usage over time.
I guess I am a bit spoiled, because I have a PC scope for getting serious and making logs.
From what I can tell, the power company does a lot of switching here.
The power is either On or Off, and when it is on, it is within 5%.
It is about normal to loose power for less than a second, but it can be off for more cycles than most electronics can recover from. A compressor may have near locked rotor amps, and TVs can make you think they are broke.
I use care when playing with electricity.
Bluebinky
Member
Jeez! No one is talking about oversizing anything. JW, my fridge does just fine on its 15A circuit with #14 wire. Is that oversized? The lights still flicker when it comes on, but you really have to be looking for it to notice. As an added bonus, the breaker doesn't trip any more if the microwave happens to be on too. The inspector told me "If I come back for the final and see that big microwave in the kitchen, you'd better have three counter-top circuits". Now I wonder, should I have put in a bigger panel, since the new one is completely full? I ran #10 to a sub-panel in the garage in case I want to run a bigger compressor or a small wire-feed welder or whatever. Should I have run #6 in case I buy an electric car some day?
As for the original question, I would use #8 on a 50A breaker to the disconnect, if it were concealed NM cable. A lot of things can and typically do go wrong with heat pumps besides a compressor motor overload. I'm not a pro and maybe I'm clueless though...
As for the original question, I would use #8 on a 50A breaker to the disconnect, if it were concealed NM cable. A lot of things can and typically do go wrong with heat pumps besides a compressor motor overload. I'm not a pro and maybe I'm clueless though...
JWelectric
Electrical Contractor/Instructor
My post was directed to the board but I will take the time to answer your questions. Being that a 15 amp circuit is the smallest one is allowed to install I would say it is perfect.
bluebinky;412764The lights still flicker when it comes on said:
Bluebinky
Member
I do understand motors. I've also seen a running 2 1/2 ton AC unit trip a known good 50A breaker with both motors running apparently normally, messed up external capacitors that drew 20A or so, flames and smoke coming out of control boards, etc. Despite what the code says, I prefer my electrical fires to be outside.
JWelectric
Electrical Contractor/Instructor
A cap that is drawing 20 amps trips a 50 amp breaker? Sounds like a bad breaker to me. Smoking circuit boards burn out in milliseconds so what is the danger?
Now comes the $64 question, if the cap is bad and the circuit board is spitting flames pray tell how the motors are running normally. I got it, neither the cap or the circuit board plays any part in how the unit works. They were installed as extras.
You can try till the cows comes home but you will never find a reason to waste natural resources by installing a larger than needed conductor to an outside unit. Your leading statement in that post is far from the truth if we are to believe the part about keeping fires on the outside.
Caps swell up and stop working and circuit boards burn and open. if the breaker tripped then it did its job and evidently there wasn't a fire or you wouldn't have seen the unit and like you said the breaker tripped so where is the problem?
I think I have figured it all out, the grass got so high that the unit couldn't breath so the cap smothered to death and the circuit board caught a fever and burned up, or was it the filter never got changed causing a high head pressure which caused the unit to short cycle until the cap failed and the board burned up.
Well it doesn't much matter as the breaker tripped and all was safe.
Bluebinky
Member
I'm not talking about one unit, but rather several different failures I have seen just in my neighborhood back in Texas. Units there usually last 10 years max due to intermittent power during storms.
Notable examples include:
1) Two different known good 50A breakers tripped by a unit that looked and ran fine.
2) A unit that tripped the breaker immediately -- external capacitor measured drawing 20A (weird) -- all units I've looked inside have one -- they go out all the time.
3) Just a control board hooked up -- no capacitor, no fan, no compressor that would trip the breaker after several minutes and smoke every time the breaker was reset.
I do wonder though. Every unit I've seen (dozen or more) that wouldn't run always tripped the breaker, not the thermal overload.
JWelectric
Electrical Contractor/Instructor
If the breaker is tripping it is doing what it is supposed to do although I have never in my entire career seen a smoked circuit board trip a breaker. Once a circuit board burns it is an open circuit and current does not flow in an open circuit.
To quote you
This still doesn’t explain how a capacitor that is drawing as high as 20 amps will trip a 50 amp breaker being that the breaker is designed to let 50 amps pass continuously. 50 minus 20 leaves 30 more amps of current.
I personally think that what you are trying your best to do is justify installing an oversized conductor to a motor load but have little or no understanding of how motor circuits function. You are grabbing at straws using scenarios of failed components in the unit to justify the waste of materials without having the knowledge of how things work.
Should either the circuit board or capacitor short out completely then the equipment grounding conductor will carry the faulted current back to the service, across the bonding jumper, through the service equipment neutral and back to the secondary of the transformer and draw enough current to cause the breaker to open. Should the breaker fail to open there will be low enough impedance on this fault current path to open a 200 amp main breaker.
If either the circuit board or capacitor fails and causes the circuit to open which in 99.9% of all cases this is what happens, then current will cease to flow and there is no danger what so ever.
Should the unit motor overheat the unit will stop as the thermal overload opens and sit silent for a few minutes as the thermal overload cools and resets and the motor starts again. This is known in the field as short cycling and is caused in most cases due to a dirty filter that causes the line set to swell a little and the Freon charge to become low. Sometimes there will be a leak that is so small it can’t be found and the same cycling occurs.
What I find to be very comical is someone using 12 gauge wire to wire 15 amp receptacles and claiming that their installation is so much safer and goes so far beyond the code which makes them such a better electrician than those who use 14 gauge wire with the same 15 amp receptacles. I suppose they have never heard the phrase, “the weakest link”.
If someone did make an installation in a dwelling unit using 12 gauge wire and hospital grade devices then they could claim the title of going beyond the code and making a better installation but you could bet your bottom dollar that they wouldn’t be wiring many homes. Then again there would still be the stab-loc breakers in the panel unless they spring for the added cost of bolt-in breakers but then again they would end up having as much invested in the electrical system as they would have in the home itself.
Of course if one was to go to the expense of 12 gauge conductors, hospital grade devices, and bolt-in breakers why not use rigid conduit to install the conductors. Being that most homes has hazardous materials such as alcohol we might as well as use class I division I type of enclosures.
Wait a minute why do all this when for almost 100 years the first section of the code book explains that a code compliant installation is free from the hazards arising from the use of electrical energy but then again there is always someone out there that knows better than all those fine folks who write the codes. But then again anyone with knowledge knows that it is those fine folks such as those posting in this forum that write the codes through the proposal process, yes it is people just like us that send in proposals to have code sections changed. Over the years I have made many proposals that were accepted in part, principle or as a whole although I have had many that were rejected.
Now it is time for me to get motivated enough to go to the college and misinform those who are trying their best to better themselves in the electrical inspection field. Of course I will only be telling them what the code says and not telling them should they see an installation as I have described above that the electrician has installed the safest of installations although they will be standing in bewilderment at such a stupid installation. I will need to instruct them to ensure that every joint in the piping system has at least 5 threads fully engaged in order to be code compliant.
To quote you
The overload is on the inside of the compressor or it is integral with the motor. It protects the motor and branch circuit from an overload due to motor failure.
This still doesn’t explain how a capacitor that is drawing as high as 20 amps will trip a 50 amp breaker being that the breaker is designed to let 50 amps pass continuously. 50 minus 20 leaves 30 more amps of current.
I personally think that what you are trying your best to do is justify installing an oversized conductor to a motor load but have little or no understanding of how motor circuits function. You are grabbing at straws using scenarios of failed components in the unit to justify the waste of materials without having the knowledge of how things work.
Should either the circuit board or capacitor short out completely then the equipment grounding conductor will carry the faulted current back to the service, across the bonding jumper, through the service equipment neutral and back to the secondary of the transformer and draw enough current to cause the breaker to open. Should the breaker fail to open there will be low enough impedance on this fault current path to open a 200 amp main breaker.
If either the circuit board or capacitor fails and causes the circuit to open which in 99.9% of all cases this is what happens, then current will cease to flow and there is no danger what so ever.
Should the unit motor overheat the unit will stop as the thermal overload opens and sit silent for a few minutes as the thermal overload cools and resets and the motor starts again. This is known in the field as short cycling and is caused in most cases due to a dirty filter that causes the line set to swell a little and the Freon charge to become low. Sometimes there will be a leak that is so small it can’t be found and the same cycling occurs.
What I find to be very comical is someone using 12 gauge wire to wire 15 amp receptacles and claiming that their installation is so much safer and goes so far beyond the code which makes them such a better electrician than those who use 14 gauge wire with the same 15 amp receptacles. I suppose they have never heard the phrase, “the weakest link”.
If someone did make an installation in a dwelling unit using 12 gauge wire and hospital grade devices then they could claim the title of going beyond the code and making a better installation but you could bet your bottom dollar that they wouldn’t be wiring many homes. Then again there would still be the stab-loc breakers in the panel unless they spring for the added cost of bolt-in breakers but then again they would end up having as much invested in the electrical system as they would have in the home itself.
Of course if one was to go to the expense of 12 gauge conductors, hospital grade devices, and bolt-in breakers why not use rigid conduit to install the conductors. Being that most homes has hazardous materials such as alcohol we might as well as use class I division I type of enclosures.
Wait a minute why do all this when for almost 100 years the first section of the code book explains that a code compliant installation is free from the hazards arising from the use of electrical energy but then again there is always someone out there that knows better than all those fine folks who write the codes. But then again anyone with knowledge knows that it is those fine folks such as those posting in this forum that write the codes through the proposal process, yes it is people just like us that send in proposals to have code sections changed. Over the years I have made many proposals that were accepted in part, principle or as a whole although I have had many that were rejected.
Now it is time for me to get motivated enough to go to the college and misinform those who are trying their best to better themselves in the electrical inspection field. Of course I will only be telling them what the code says and not telling them should they see an installation as I have described above that the electrician has installed the safest of installations although they will be standing in bewilderment at such a stupid installation. I will need to instruct them to ensure that every joint in the piping system has at least 5 threads fully engaged in order to be code compliant.
Bluebinky
Member
JW I personally think that you have such a closed mind that you believe that everything I say must be wrong somehow. Other than that, as I have said before, I respect your intelligence, experience, and insight.
I happen to be a highly trained Engineer with far more "formal education" than you will ever have. That does not necessarily make me better than you nor smarter. It also doesn't make me clueless (I'm hoping you just have a warped sense of humor about that). Since I have followed a different career path than you and lived in different places, I have seen and experienced some very different things than you. However, somewhere along the way, I managed to learn that it is not nice to twist our friends' words around and selectively use them to hurt each other.
I agree with you that going oversize on wiring accomplishes nothing except wasting resources and money. I do hope that no houses burn down because a heat pump failed in a way that never happens except in Texas ... that would be a shame.
I happen to be a highly trained Engineer with far more "formal education" than you will ever have. That does not necessarily make me better than you nor smarter. It also doesn't make me clueless (I'm hoping you just have a warped sense of humor about that). Since I have followed a different career path than you and lived in different places, I have seen and experienced some very different things than you. However, somewhere along the way, I managed to learn that it is not nice to twist our friends' words around and selectively use them to hurt each other.
I agree with you that going oversize on wiring accomplishes nothing except wasting resources and money. I do hope that no houses burn down because a heat pump failed in a way that never happens except in Texas ... that would be a shame.
DonL
Jack of all trades Master of one
Many book smart people have a problem in the real world.
Experience is the best teacher.
JWelectric
Electrical Contractor/Instructor
Well with all that formal education and the long horn heat pumps that have spit fire how many destroyed the conductors supplying the unit?
Over my career I have found damn few formally educated engineers that had enough sense to get in out of the rain. I have known many engineers that had a background in IT and a few with a background in graphics that knew very little about current flow but yet they were quick to get on their soap box and preach about how many years they walked back and forth to school barefooted in the snow uphill both ways.
Now one doesn’t have to have gone to school more than a couple of days to be able to see that the wiring supplying those capacitors and circuit boards in electrical appliances if far from being as large as the ones supplying the appliance. If one had seen the circuit board before it spit fire for days on end one could see that the wiring of the circuit board is less than one tenth the size of the conductors supplying them.
I will admit that my formal education came from colleges and universities here in the hick state of NC but I too have been to the steer state and even have pictures of me standing with the Hollywood sign in the background. I have stepped into the Duke’s square and tasted the salty waters of Ca’s ocean. I have been in all of the lower 48 states but that in no way makes me smarter when it comes to the theory of current flow.
I am almost 63 years old and have been studying the electrical codes starting at 2 months before my 16th birthday. I have put my hands on about everything one can think from a single cell to 4160 volts in water treatment plants. I have been involved with two different and separate arc flashes that some say is a miracle that I stand before them today. For the past 14 years I have been teaching all three levels of electrical inspection classes and for the past 4 code cycles have helped author the manuals that the community colleges are required to use to hold these classes.
Once I got my sheepskin I didn’t go into some office somewhere and sit on my toucan looking at and drawing pictures but instead I got out in the real world and put my education to work and spreading my knowledge and experience to those who are willing to learn. When it is something that is my opinion and not based on facts I am always sure to point out it is my opinion and not facts.
Just like I do here I will sit quietly until I hear or see someone trying to give bad information in the name of safety. I have nothing against you personally but some of the information you post is far from being factual. I ask myself just what difference it makes where a fire starts if after it is over my home is nothing more than a pile of ashes.
When I took the role as moderator on this site built to help the do-it-yourselfer I promised that misinformation would be met head on. I do not do so in order to boast of my knowledge or to show just how little knowledge anyone here has but instead to ensure that the visitors of this site is getting the facts not a lot of hogwash that is nothing more than a figment of someone’s imagination or information that leads to unsafe installations or methods used.
If you want to post your opinion based on your formal education please expect others to question you as to why you feel that your information is indeed factual. If you are just wanting to post to spend the time of day then for the love of those seeking information let it be known that it is nothing more than a pass time for you but I ask that you don’t post information and say it is because you barely passed some class in college. Some of these fine folks can hardly feed their self and don’t have extra money lying around like the two of us with all our formal education to spend on some half-baked idea that was read on wiki.
Over my career I have found damn few formally educated engineers that had enough sense to get in out of the rain. I have known many engineers that had a background in IT and a few with a background in graphics that knew very little about current flow but yet they were quick to get on their soap box and preach about how many years they walked back and forth to school barefooted in the snow uphill both ways.
Now one doesn’t have to have gone to school more than a couple of days to be able to see that the wiring supplying those capacitors and circuit boards in electrical appliances if far from being as large as the ones supplying the appliance. If one had seen the circuit board before it spit fire for days on end one could see that the wiring of the circuit board is less than one tenth the size of the conductors supplying them.
I will admit that my formal education came from colleges and universities here in the hick state of NC but I too have been to the steer state and even have pictures of me standing with the Hollywood sign in the background. I have stepped into the Duke’s square and tasted the salty waters of Ca’s ocean. I have been in all of the lower 48 states but that in no way makes me smarter when it comes to the theory of current flow.
I am almost 63 years old and have been studying the electrical codes starting at 2 months before my 16th birthday. I have put my hands on about everything one can think from a single cell to 4160 volts in water treatment plants. I have been involved with two different and separate arc flashes that some say is a miracle that I stand before them today. For the past 14 years I have been teaching all three levels of electrical inspection classes and for the past 4 code cycles have helped author the manuals that the community colleges are required to use to hold these classes.
Once I got my sheepskin I didn’t go into some office somewhere and sit on my toucan looking at and drawing pictures but instead I got out in the real world and put my education to work and spreading my knowledge and experience to those who are willing to learn. When it is something that is my opinion and not based on facts I am always sure to point out it is my opinion and not facts.
Just like I do here I will sit quietly until I hear or see someone trying to give bad information in the name of safety. I have nothing against you personally but some of the information you post is far from being factual. I ask myself just what difference it makes where a fire starts if after it is over my home is nothing more than a pile of ashes.
When I took the role as moderator on this site built to help the do-it-yourselfer I promised that misinformation would be met head on. I do not do so in order to boast of my knowledge or to show just how little knowledge anyone here has but instead to ensure that the visitors of this site is getting the facts not a lot of hogwash that is nothing more than a figment of someone’s imagination or information that leads to unsafe installations or methods used.
If you want to post your opinion based on your formal education please expect others to question you as to why you feel that your information is indeed factual. If you are just wanting to post to spend the time of day then for the love of those seeking information let it be known that it is nothing more than a pass time for you but I ask that you don’t post information and say it is because you barely passed some class in college. Some of these fine folks can hardly feed their self and don’t have extra money lying around like the two of us with all our formal education to spend on some half-baked idea that was read on wiki.
Bluebinky
Member
If you'd rather I didn't post, then I'd be fine with that. Not that it matters to you, because you could always just shut me down...
I was slightly amused about the whole "clueless" thing and even the "problem in the real world" from DonL. But the lecture about having some half baked education handed to me on a silver platter was very rude. When I was a teenager, I had to leave everything I knew to get away from a very bad situation. I had no where to sleep, nothing to eat, no high school diploma, and no hope. It took a long time with a lot of hard work and major setbacks before I was able to finally "prove to the world" that I was worthy of holding a job doing the things I always loved. I would have a PhD, but my professor thought it was funny to step on the cleaning lady's dust mop, since she was a mere low-life. That was my last day there...
About three hours ago, the ANA flight out of San Jose headed for Tokyo flew by. What a beautiful machine -- with long swept wings like a bird and tiger teeth engines that purr like a giant kitten. I just had to go outside and watch -- again. Hopefully, the "teething problems" are over and the plane will be a success. Any body else here know the not so well known secret that a major contributor to the battery fires was that the battery management software did not stop charging after detecting a sudden voltage drop due to a shorted cell? I don't claim to know all the details, but I can tell you it would not have happened if I had been on the team. Clueless, I am not.
When I was six years old (before JW got into electronics), my dad gave me a 2 hp Briggs & Stratton engine. He said, "if you can take it completely apart and then put it back together, it's yours". That day the world changed. By the time I was 12, I could start a locomotive, hook up 100+ cars and get everything moving. I had my commercial broadcaster's license before my first driver's license, was laughed at in high school because my 64 Falcon was always broke down, etc. Am I a top-notch mechanic, locomotive engineer, heavy equipment operator, choker setter, broadcast engineer, pilot, framer, plumber, electrician, ...? Not really, but I do OK in the real world, thank you.
JWelectric
Electrical Contractor/Instructor
It is not that anyone minds you posting but when you get set on proving something has to be when the facts are they don’t then I do get a little annoyed. Then you start with you have seen or have done when any seasoned pro knows different and again I get a little irritated.
I think that it is wonderful that you worked so hard to achieve the goals you had set for yourself and completed your education even though you were so mindless to let another guide you away from having a PHD.
One thing I have noticed about you is that if one listens to what you say one can learn a lot about you as well as your knowledge such as your comment about the software of the airplane. This tells me that your background is in computer software programing and my background is strictly in electrical engineering with a major in the NEC.
Through your post you seem to have the same principle as many other engineers that bigger is better but then again most of them have a math background and absolutely no knowledge of the codes that mandate the installation of an electrical system. Yes I have many electrical engineers that take my code classes simply because during the four years of their education they never saw a NEC.
If I asked you a question concerning the broadband that I am using to send this post you could dazzle the forum with your math equations but should I ask you the code requirement for installing the cable in my home you would have to do research before you could answer.
What the fine folks that ask questions on this site are interested in is not the math but the requirement for installing the cable. There is a big difference between the two. I will always give them the code compliant answer and not what I think would be a better idea and then argue that I am right just because I watched tumble weeds roll around in the steer state.
I can do the math for the available fault current of a service disconnect but those who come here asking about their service could care less about the available fault current but instead are looking for answers concerning the wire and breaker size. I can do a three point resistance test for ground rods but those asking questions about their grounding electrode system are not looking for a huge equation but only how many rods they need and how far apart.
Have you ever noticed I don’t get involved in trouble shooting unless someone starts giving bad or dangerous advice? I can’t trouble shoot a heat pump down there where the antelope play while watching my sour mash cooking off. The only and best advice I could give them is if the capacitor is smoking or the circuit board is spitting fire is to turn it off and call an electrician.
I think that it is wonderful that you worked so hard to achieve the goals you had set for yourself and completed your education even though you were so mindless to let another guide you away from having a PHD.
One thing I have noticed about you is that if one listens to what you say one can learn a lot about you as well as your knowledge such as your comment about the software of the airplane. This tells me that your background is in computer software programing and my background is strictly in electrical engineering with a major in the NEC.
Through your post you seem to have the same principle as many other engineers that bigger is better but then again most of them have a math background and absolutely no knowledge of the codes that mandate the installation of an electrical system. Yes I have many electrical engineers that take my code classes simply because during the four years of their education they never saw a NEC.
If I asked you a question concerning the broadband that I am using to send this post you could dazzle the forum with your math equations but should I ask you the code requirement for installing the cable in my home you would have to do research before you could answer.
What the fine folks that ask questions on this site are interested in is not the math but the requirement for installing the cable. There is a big difference between the two. I will always give them the code compliant answer and not what I think would be a better idea and then argue that I am right just because I watched tumble weeds roll around in the steer state.
I can do the math for the available fault current of a service disconnect but those who come here asking about their service could care less about the available fault current but instead are looking for answers concerning the wire and breaker size. I can do a three point resistance test for ground rods but those asking questions about their grounding electrode system are not looking for a huge equation but only how many rods they need and how far apart.
Have you ever noticed I don’t get involved in trouble shooting unless someone starts giving bad or dangerous advice? I can’t trouble shoot a heat pump down there where the antelope play while watching my sour mash cooking off. The only and best advice I could give them is if the capacitor is smoking or the circuit board is spitting fire is to turn it off and call an electrician.
Bluebinky
Member
Just to set things straight. I spent most of my life in Seattle, and did not study software engineering. I am a self-taught Electrical Engineer who happens to have a degree. I also suck at math, but that did not stop me from learning it. Math is a fall-back for when words fail. I did not let another "guide me away" from anything but rather suddenly realized that I was not and never would be a "snob". It is amazing how wrong one can be when reading between the lines.
I will stop posting because it always seems to end up in an argument with you. I still wish you would stop making non-standard use of terms like "phase" and "short circuit" and such, because it detracts from an otherwise excellent resource.
I will stop posting because it always seems to end up in an argument with you. I still wish you would stop making non-standard use of terms like "phase" and "short circuit" and such, because it detracts from an otherwise excellent resource.
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JWelectric
Electrical Contractor/Instructor
Here is one of several
Neutral Point. The common point on a wye-connection in a
polyphase system or midpoint on a single-phase, 3-wire system,
or midpoint of a single-phase portion of a 3-phase delta
system, or a midpoint of a 3-wire, direct-current system.
Overload. Operation of equipment in excess of normal,
full-load rating, or of a conductor in excess of rated ampacity
that, when it persists for a sufficient length of time,
would cause damage or dangerous overheating. A fault,
such as a short circuit or ground fault, is not an overload.
I suppose that some have self-taught themselves past knowing just what are common terms and what are not when it comes to talking about electrical circuits.
The terms phase and short circuit are found in the definitions of the NEC and several times throughout the book. Maybe those folks are dummies like me or have not yet gotten their formal education. It might be that they don’t know that these are non-standard terms when it comes to talking electrical.
Neutral Point. The common point on a wye-connection in a
polyphase system or midpoint on a single-phase, 3-wire system,
or midpoint of a single-phase portion of a 3-phase delta
system, or a midpoint of a 3-wire, direct-current system.
Overload. Operation of equipment in excess of normal,
full-load rating, or of a conductor in excess of rated ampacity
that, when it persists for a sufficient length of time,
would cause damage or dangerous overheating. A fault,
such as a short circuit or ground fault, is not an overload.
I suppose that some have self-taught themselves past knowing just what are common terms and what are not when it comes to talking about electrical circuits.
The terms phase and short circuit are found in the definitions of the NEC and several times throughout the book. Maybe those folks are dummies like me or have not yet gotten their formal education. It might be that they don’t know that these are non-standard terms when it comes to talking electrical.
Pool Heat Pump arrived today. My pool guy set it in place and plumbed it in. I wired it.
Nameplate called for a Minimum Circuit Amps 36.2, Maximum Breaker size 60 Amps.
Since MCA exceeded 35 Amps (36.2) I wired it with 2 black 10' lengths of #8 THWN to the existing 50 amp breaker, and 1 Green 10' #10 length. Total cost $15.
I ran a #10 bare solid bonding wire to tie into the existing bond of the pumps.
#10 THWN was 10 cents per foot cheaper than #8 so it cost me $2 more.
I already had 3/4" liquid-tight flex and fittings.
Nameplate called for a Minimum Circuit Amps 36.2, Maximum Breaker size 60 Amps.
Since MCA exceeded 35 Amps (36.2) I wired it with 2 black 10' lengths of #8 THWN to the existing 50 amp breaker, and 1 Green 10' #10 length. Total cost $15.
I ran a #10 bare solid bonding wire to tie into the existing bond of the pumps.
#10 THWN was 10 cents per foot cheaper than #8 so it cost me $2 more.
I already had 3/4" liquid-tight flex and fittings.
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