Thanks for the thorough explanation. Much appreciated
@nickhermary1046
3 жыл бұрын
Glad it was helpful!
@joelsmith724
3 ай бұрын
Awesome video where are you finding this table 2 in the codebook?
@nickhermary1046
3 ай бұрын
Yes in the Canadian Electrical Code book
@abdullahkhawatmi1859
2 жыл бұрын
Many thanks for the explanation. is 0.8 the power factor of the water heater or what?
@nickhermary1046
2 жыл бұрын
No, the 0.8 is because the water heater is a continuous load and the circuit breaker is marked for continuous operation at 80% (80% is a default unless otherwise stated). We increase the calculated current draw because the load is on for longer than it is off. Because it is on longer, it can draw rated current for longer and thus increase the heat through the conductor which could lead to tripping due to overload. If we increase the calculated draw of the heater before we size the conductor, the potentially larger conductor can help dissipate the heat from the continuous draw of current and avoid nuisance tripping.
@abdullahkhawatmi1859
2 жыл бұрын
@@nickhermary1046 I really appreciate your help. Regarding the ratings, what is the difference between 80% and 100% circuit breakers? What I have got is that if the load is continuous, we should take a safety factor of 1.25 of the rating load and then we decide the rating of the breaker and the cable; but what makes me confused is what is the difference between 80% and 100% CB rating and when they can be used? I am really sorry for taking some of your time, but I will appreciate it if you clarify this point for me. again, many thanks for sharing this valuable information.
@nickhermary1046
2 жыл бұрын
@@abdullahkhawatmi1859 The 80% (standard-rated) breaker can only be applied continuously (defined as 3 hours or more by the NEC) at 80% of its continuous current rating. 100% rated circuit breakers can be applied at up to 100% of their current rating continuously. Breakers rated at 80% can be applied at 100% of their rating if the loading will last for less than 3 hours. You need to know the rating of the breaker before you decide what calculated amapacity you will use.
@abouzarfallah7012
Жыл бұрын
Hi Nick Your videos are tremendous I have just some questions which has confused me 1- Should we consider residential load (including receptacles, lightings, washing machine, hot water tank, AC, dryer and ...) continues or non-Continuous? 2- For what type of load should I follow rule 14-104 2) ? For commercial or industrial loads am I allowed to follow it? Thanks again
@nickhermary1046
7 ай бұрын
The CEC states the rules for deciding whether a load is continuous or not. Basically if it's on mor than off it will be considered continuous. 14-104 applies to the general sections of the code, section 2-16 and 26. If you are using other sections the code (section 28 for motors) 14-104 does not apply.
@garyshannon5772
2 жыл бұрын
A continuous load is 1.25 %.
@nickhermary1046
2 жыл бұрын
When the breaker is marked for continuous operation at 80%, yes the load is increased to 125% by dividing the calculated load by 0.8.
@abouzarfallah7012
Жыл бұрын
Electric water heater has thermostat then isn't it under section 62 coverage. Section62 covers any fixed electric heater
@nickhermary1046
Жыл бұрын
Section 62 is for space heat, using an electric heating device to heat an area. Electric hot water tanks are used to heat water, not the surrounding air, for example you don't turn an electric water heater on to warm up your house.
@abouzarfallah7012
Жыл бұрын
@@nickhermary1046 but water heater like space heater has thermostats and it means it can not be continuous load
@nickhermary1046
Жыл бұрын
@Abouzar Fallah when an electric hot water tank is first filled with cold water, depending on the size, it could definitely be on for more than 1 hour in a 2 hour period to heat all of the water to the preset temp (8-104 (3)). Then it would be considered as a continuous load.
@gabopani
Жыл бұрын
Can i apply 2nd example for AC installs ? and those roof topt units? thank you
@nickhermary1046
Жыл бұрын
No, the calculation and code reference was from section 62 from the CEC which is for fixed electric heating systems. Most air conditioners and roof top units have nameplate information that provides information about the requirements for branch circuit connections. The nameplate information takes into account all the different types of loads with the units.
@gabopani
Жыл бұрын
@@nickhermary1046 thank you so much man .
@gabopani
Жыл бұрын
but in the AC we have to size the wire to the braker or to the min circuit ampacity, example, one trane AC is min circuit amp 28.8 amp and max fuse 50 amp . what size wire it will be ?#10 or #8
@nickhermary1046
Жыл бұрын
Normally, you would size the conductor for the calculated ampacity, and then the max overcurrent will be sized from the conductor ampacity. The termination temperature will also come into play prior to selecting the conductor.
@abouzarfallah7012
Жыл бұрын
Hi Nick what is the answer of this redseal exam what is the minimum conductor size of a 20KW heater?
@nickhermary1046
Жыл бұрын
The question is vague, so it's hard to answer properly without more information.
@abouzarfallah7012
Жыл бұрын
@@nickhermary1046 It is all. Exactly same question came in exam
@nickhermary1046
Жыл бұрын
@@abouzarfallah7012 there is no voltage listed, so there is no way to determine the current draw.
@krutchmedia7595
7 ай бұрын
I have to speak and say, NO. Water heater is intermittent due to thermostat. Filling the water heater has nothing to do with current so therefore you don't have any instances where that water heater will heat for 3 consecutive hours. When a new water heater is installed, the breaker for it must remain OFF until it is FILLED. If not the elements will burn up inside. Your doing good man, but take your time.
@nickhermary1046
7 ай бұрын
An electric hot water tank can be on for more than an hour in a 2 hour period which makes it continuous according to the Canadian Electric Code. Depending on the size an electric hot water tank could def be continuous. A gas heat hot water tank would not be of course as it uses gas to heat the water.
@krutchmedia7595
7 ай бұрын
@@nickhermary1046 ahhhhh…. In the U.S. it’s 3 hours. Good stuff. I liked what you were doing and am glad that your info was correct. I also noticed that the video was from 2 years ago, (lol) I was figuring, “by now he also knows it’s 3 hours”. But hey, it still shouldn’t be continuous because it’ll never run 2 hours even. Talking things out! Any thoughts?
@nickhermary1046
7 ай бұрын
@krutchmedia7595 Yes arguably an electric hot water tanks time to heat up will differ depending on size. The biggest draw would be starting from a full tank of cold water. For an average 40-gallon electric hot water tank it will take about 60 to 80 minutes and for an 80-gallon tank about 2 hours. So to keep the water warm it would not run continuously (utilizing the thermostat) but starting from cold it could run continuously enough to give nuissance tripping depending on size of the hot water tank 🤷♂️
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