Building new home, need help prepping for electric brewing

[itsnotrequired]

The only thing I'm concerned about conveying is the size of the exhaust outlet. If I tell them a six inch exhaust hole for brewing I'm sure they'll have no idea what actually needs to be done...and to be fair, being so new to electric brewing, neither do I.

just tell them it needs to accommodate a 6" round exhaust duct, they'll know how to size the opening. bathroom, dryer, whatever, the opening is all sized the same. no doubt they will ask what it is for, try explaining then. the exhaust opening should be in the rim joist.

 

[ajdelange]

I'd definitely go with 400 Amp service and a subpanel for the brewing. Of course I'm saying this without knowing what else you are planning. There are detailed instructions on how to size the service (so many KVA per square foot, washer and dryer loads multiplied by a factor to account for the fact that they are not used all the time, so much for each motor etc) in the code but electric breweries aren't in there. Things like that and you wife's pottery kilns make the sizing difficult and it more or less comes down to what the electrician decides he should install based on what he thinks the inspector will allow and the utility will accept. It seems one can get a rough idea of required service by adding up all the breakers and dividing by 4 and I got my electrician to admit that this is pretty much what he does. If you have a dual pole breaker that counts as two breakers. Thus a two pole 50 amp breaker would add 100 phase amperes to the total implying an extra 25 amps demand on the service.

The utility may indeed weigh in Quebec Hydro made me install 600 amp service even though I explained over again that this was way overkill (OK, my French is non-existent) and I'm pretty sure they made me do this because I put a total of (3) 50 amp outlets in the garage and boat shed thinking I might install an electric brewing rig in one or the other of those locations. Using my rule of thumb those 3 outlets would impose 3*2*50/4 = 150 amps on service requirement. Suppose I have 50 breaker poles (not unreasonable in a medium sized modern house) averaging 25 A each (some are clearly bigger than 20 A) that would give 1250 phase amperes to which add the 600 phase amperes for the three 50 amp outlets and I'd have 1850 phase amperes. Divided by 4 that's 462.5 which is over 400 and the next service size is 600 so perhaps that's why they insisted on 600 amp service despite my pleadings that those outlets would only be used a tiny fraction of the time and that I am smart enough not to use them heavily when emergency electric heat is on. I guess the point is that the next guy who moves into that house may not be so smart.

Needless to say this cost me some $. New pole transformer, new feed wires and the service entrance equipment and switch gear (they made me put in a 600 amp transfer switch for my 200 amp generator!). So what did the actual loading turn out to be? The picture below shows it for the period starting December 1 and ending this morning (Jan 6). My 600 amp service has never had a demand of more than 140 amps imposed on it. Note that there was no brewing activity. Also note that is has been bloody cold in Quebec this December and, so far, in January. Had I decided to brew on the coldest day of the year (when the use of E heat was responsible for the peak demand), and used the full 50 amp capacity of one of those outlets, I would have had a peak load of 190 amps. That huge transfer switch, big transformer and load shedding equipment were totally unnecessary as I tried fruitlessly to explain to the electrician when he told me I needed all that stuff per Hydro Fiat.

So I guess my advice would be to sit down with your electrician and ask him what size service he is planning and how he arrived at that number (you would expect it to be easier if you are both native speakers of the same language but that may non necessarily be the case). If he came up with a load that is less than 150 A (unlikely unless it's a pretty small house) then he would use 200 amp service and you can just tell him to install another 50 amp outlet (fed from a GFCI breaker) in an existing panel or sub panel. If the estimated load is greater than 200 A but less than 350 amp he will have specified 400 amp service and again you can install another 50 A circuit without trouble. The situation gets sticky if the has estimated the load at just a few amperes below 200 or 400 as and extra 50 amps would put you into the next bracket. If that's the case you would have to convince him that the derating factor for this outlet is small. A 20% factor would only add 5 amps to the service requirement and if he is at 390 Amps a 50 amp circuit with that derating factor would bring it to 395 and you'd still be under 400.

I'll also mention something I wish I had thought of. In shop, garage, brewery, basement etc. have the guy pull 12/3 to the outlet boxes rather than 12/2 and install receptacles that have the breakable links between the two outlets. This way you have 120 and 240 available at each outlet. You can use them as normal duplex outlets until such time as you might want to install a 240 volt outlet for a piece of shop equipment, for example or for temporary 240 you can make up an adpater cable with (2) 120V plugs on one end and a 240 V receptacle on the other.

 

[lschiavo]

Wow AJ. You could start a factory in your house. I'm surprised you couldn't declare one 200A panel an emergency panel and put a non-service rated transfer switch on it's feeder. That's what we did in the house I mentioned above. Saves tons of money.

Your situation with electric heat is unheard of around here anymore. It does add a large load that must be accounted for though as you mentioned with your peak loading.

A lot depends on appliances. Gas cooking and dryers drop the load calculations a lot. I would recommend asking you electrician to do a calculation for you. It's quite simple actually. The worst part is gathering the information on appliances and things you probably don't even have yet.

 

[ajdelange]

Wow AJ. You could start a factory in your house.

I was afraid that Hydro would report the installation to the RCMP as there are those in my area that engage in certain indoor agricultural practices during the long winter which consume a lot of electricity for grow lights.

I'm surprised you couldn't declare one 200A panel an emergency panel and put a non-service rated transfer switch on it's feeder. That's what we did in the house I mentioned above. Saves tons of money.

I tried something similar. I gave them instructions that the three 50 Amp outlets should be connected before the transfer switch so that their loads would never go through it but they kept insisting that Hydro said if there is a load on the property and a generator all the loads have to go through the transfer switch. That is, of course, ridiculous. They wired the three to the load side and used a contact on the switch to shed the three (and, BTW, my E-heat) whenever the generator runs though I had given instructions that the E-heat was to be staged when the generator came on. I even asked the general contractor if I should sue these guys and he made it clear that it would be nothing but a nightmare (or couche mar as they say up there). But yes, that transfer switch definitely belongs in a factory!

Your situation with electric heat is unheard of around here anymore. It does add a large load that must be accounted for though as you mentioned with your peak loading.

Note that the utility name is Quebec Hydro. Electricity is very cheap up there - about $0.08 kWh which in US $ is about $0.06. Use that to run a heat pump with a COP of nearly 4 and you've got cheap BTUs. Last month E-heat only ran 1.1 hrs. That cost me 1.1*15*0.06 = $0.99

A lot depends on appliances. Gas cooking and dryers drop the load calculations a lot. I would recommend asking you electrician to do a calculation for you. It's quite simple actually. The worst part is gathering the information on appliances and things you probably don't even have yet.

At this point you are clearly not addressing me any more but I will, nevertheless, comment. It may be well worth Marc77's time to get a copy of the code or a summary (www.buildersbook.com) and figure out how to do a load calculation himself. He will need to know about the number of circuits in the rooms, the square footage of the house washers, dryers etc.

 

[SanPancho]

Thats crazy. We run a restaurant, bar, and 15bbl brewery on 400amps service. Holy cow.

 

[lschiavo]

Thats crazy. We run a restaurant, bar, and 15bbl brewery on 400amps service. Holy cow.

I know. I find many people severely overestimate their electrical service needs. It doesn't cost much to go from 100A to 200A so that's a no brainier on a new house. Going up from there gets costly quickly. That's why I mentioned the 11,000 sq-ft house (perspective). I believe the calculation came to about 280A. Hence the 320A service. That's a pretty big house and nowhere near needing a 400A service.

 

[ajdelange]

My house (in Va) is certainly much smaller than 11000 square feet and has 400A service. Am I way oversized? Over the last month the largest load I saw was 159 amps (this morning). The average load was 36.3 amps, and the median 35.2. The load was less than 100 amps 99.3% of the time. So ostensibly one might be tempted to say that I am oversized. But all I have to do is turn on the ovens, the dryer, set the thermostats up a bit and turn on some lights and I'm up to 200 amps. Clearly as there are lots of lights, space heaters, toasters, compressors, crockpots, dryers, saws, grinders... that I didn't turn on it's plain that I could exceed 200 amps by a fair margin but the evidence of the month's power consumption history makes it plain that for me to do so would be quite unlikely. I exceeded 150 A 0.015% of the time last month but keep in mind that as the total data collection period was 40,259 minutes that means more than 150 A was drawn for 6 minutes. So am I oversized? No. I'm just about right. As I can conceptually draw over 200 amps (even though doing so is so rare an event that I have not yet witnessed it it normal operation of the house) I need 400 amp service just as parts of my house had, per code, to be reinforced to withstand winds that I've never seen and most probably will not see in my lifetime.

The engineer in me says that the way to size a service is to collect data and size the service as the mean load plus some number of standard deviations. For the December data that number here is 18.6 which I am confident is plenty big enough. Were the service 200 amps n would be 8.2 which clearly is too small. Of course you can't do this when you are designing a house so the writers of the code have to do the next best thing which is to tally up all the loads and try to accommodate the fact that they are unlikely to be on at the same time through the use of load factors. So I think that though service sizing is very conservative it needs to be so. 18.6 sigmas sounds like an insane number but keep in mind that the distribution is far from Gaussian (skew 0.64, kurtosis 0.62).

 

[lschiavo]

It is very enlightening when you can look at historical data. From what you have presented, you would never have tripped a 200A main. IMO, you should have a 200A service.

Sure, there is potential to overload with any service. What would be the penalty if an overload happened? ...reset the main breaker. It's such an unlikely event to overload with no real penalty. The almost negligible chance of an overload does not justify the extra cost of an oversized service IMO.

 

[ajdelange]

It is very enlightening when you can look at historical data. From what you have presented, you would never have tripped a 200A main.

In the normal operation of the house in the time period for which I have records I did not exceed 200 A. But it is also clear that on a cold night where the A/A heatpumps switch over to E-heat and both compressors in the W/W heat pump are running simultaneously 48% of the time if my wife has got something in the ovens, my son is doing laundry and I've left lights on in the brewery and garage, I'm going to go over 200 Amps.

IMO, you should have a 200A service.

The most important aspect of this discussion to me is that your opinion is not shared by the NFPA nor, consequently, the building inspector, my insurance company, or my electrician. Nor do I share it. Given that service comes in chunks of 200A it is clear that 400A service is right for me. Now when I installed a generator last spring the same question came up: how big should it be and how big should the transfer switch be. My electrician (a good one - he listens to his customers) looked at my panels stuffed with probably, at that time, around 2200 - 2300 (it's 2565 now) phase amps worth of breakers, divided by 4 and concluded I had 600 amp service. I showed him load data but he wasn't really convinced until I sent him a photo of the service entrance with two fat CT's labeled 400 in big letters. 600 would be overkill. To draw more than 600 amperes every breaker in the house would have to be loaded to near its label capacity. The highest load I have observed represents 12% loading per pole relative to the rated breaker size and a 400 amp load would represent 31%. That's plenty of margin for the way I use electricity.

Sure, there is potential to overload with any service. What would be the penalty if an overload happened? ...reset the main breaker.

In my case the penalty would be going out into the freezing cold to replace two of these puppies in the main disconnect.

A big PITA. If I'm not here it would mean my spouse sitting in the dark and cold until I got home. I'm getting old enough that I have to recognize that the time when I'm going away and not coming home is not so far off as it used to be. After that, it means my wife sitting in the dark and cold waiting for the electrician to come. BTW, if the main disconnect had breakers rather than fuses it would be the same. My wife would have no clue as to what to do.

It's such an unlikely event to overload with no real penalty. The almost negligible chance of an overload does not justify the extra cost of an oversized service IMO.

Well, that's your opinion. I just wouldn't be comfortable based on what I have installed in this house (not typical by any means) and what the data I've collected tell me with 200A service. I'd have no room for expansion. And the potential penalties are indeed greater than you seem to think. The mjor one you missed is that if I presented a 200 amp service for inspection after the work I did last spring I would have failed and would require rework to get up to 400A service. That would cost me a lot of bucks, no doubt.

But now on to the fun part. Can I use a month of data in which I didn't see load over 200 amps to predict how many minutes in a year I might see over 200 amps? We, sure I can but I can't say how good the prediction is until I have a year's worth of data. The way I did it is illustrated in the graph below. The solid red curve shows, on the left axis, the number of minutes in a year for which the load would be, based on the distribution of loads in December, above the load shown on the x-axis. The dotted curve is the Weibull distribution that best fits the December distribution.

You can draw your own conclusions. You would probably argue that at one minute a year it is not significant and might even reason that a breaker might not trip under load exceeding its rating for a minute or less. I'd reply that yes, that may be true but years of engineering practice have taught me that when one is this close to the limit it is best to 'err' on the safe side. The peace of mind is well worth the money.

 

[SanPancho]

I know. I find many people severely overestimate their electrical service needs. It doesn't cost much to go from 100A to 200A so that's a no brainier on a new house. Going up from there gets costly quickly. That's why I mentioned the 11,000 sq-ft house (perspective). I believe the calculation came to about 280A. Hence the 320A service. That's a pretty big house and nowhere near needing a 400A service.

But as noted above, sometimes the engineering requires it. I guess it just depends on your local utilities. Here in CA, we are all about conservation and efficiency so you gotta spend crazy amouts for energy code work. And then after that, being in an urban area, even when you show large demand you practically gotta beg the city to give you extra room for future growth. They are paranoid about folks using extra capacity for un permitted work down the line, so the locals wont approve 600 if the calcs show you could get by with 400, even if the utility approves it.

 

[ajdelange]

I was not quite happy with the fact that while the distribution in #39 fits the observed data quite well below 50 amps it doesn't fit that well above 50 and we are trying to use it to see what might happen at 200 amps. So I looked at the data set again up to about 3 this afternoon but this time fit the log of the probability. The figure below shows a much more convincing fit than in #39 and so I am much more confident in its projections.

While at it I also looked at a data set from up north going back to early October. The results of a log fit to that are in this picture

The most startling thing to me (the nice fits over the regions of measurement are of course pleasing too) is that while the electrical systems, installed appliances, HVAC gear etc. in the two houses are quite different the shapes of the distributions are very similar and the shape parameters (lambda) confirm this is being numerically quite close. Note that the vertical axis is now in seconds rather than minutes.

The McLean curves predict that 200 amperes would be exceeded for about 10^2.6 = 398.107 seconds per year. It is reasonable to assume that distributed among these 6 minutes there would be a period or periods of time long enough to cause the tripping of a 200 amp fuse or breaker. This reinforces the conclusion that is prudent to have the next size service i.e. 400 amperes. The projected time for demand greater than 400 amps is seen to be 10^-4 sec i.e 100 microseconds. It's clear that a service greater than 400 amps is not necessary and 600 would be absurd. But that is what the pros recommended based on the breakers in my panels.

In Ogden the house is smaller and hasn't nearly so many gadgets and doodads so the loads are generally smaller. The Ogden curve suggests that 200 amps will be exceeded 10^0.8 = 6.3 seconds a year. That is much closer to the edge and I would have been frustrated, had I this perspective, that I could almost get away with a 200 amp service there but I wan't given a choice. The electrician did what he thought he had to against my specific instructions (I was down in Virginia when he installed this stuff). 200 amps probably is the right size for Ogden even so it is so close to borderline. The curve suggests that 400 amp would be exceeded for about 4 nS. I don't think any breaker of fuse is going to pop in that time.

All this is fascinating, at least to me, but I don't see how it is going to be of help to OP as his is new construction and he has no history. So I still think the best he can do is count up the pole-amperes planned for his panels and divide by 4 or go through the details of the code load calculation.

I'd like to thank you guys for getting me thinking about this. This method of looking at the load data has got me confident that it really means something. Maybe I can use it as a basis for suing the electrician up north!

 

[Marc77]

Just to get all the details out there the house will only be a smidge over 2700 sq ft with the basement unfinished (maybe another 900 sq ft there). Two ovens (not a double oven), garage fridge, kitchen fridge, a dryer and the brewery will be the main draws. Yes there will be other draws like hair dryers, other appliances, tvs (4), etc. But nothing that to me screams put 400 amp service in instead of the 200 that comes standard.

 

[itsnotrequired]

what do you have in the way of gas appliances? water heater? furnace? anything else?

 

[ajdelange]

The factor that will determine whether or not you need more than 200A is how you heat the place and whether your stove/oven/cook top are gas or electric. If you are going to use gas or oil then yes, you should be OK with 200A service if you have no air conditioning but if you are going to use electric (direct or heat pumps) for the heat and cooking then the story changes. The cheapest operating costs you can realize are with ground loop heat pumps but few want to make the initial investment required. Air to air heatpumps cost much less to install but both use lots of electricity. Figure on about 1400 KVA/ton (a ton is 12 kBTU/hr so you will probably need 5-8 tons). Also how you do backup heat is a big factor. A/A heatpumps usually use electric backup but it is possible to back up with gas or even oil. In any case the correct sizing can vary quite a bit depending on HVAC and appliance choices. Presumably some decisions have been made at this point as to how these matters are to be handled and your contractor should have done a load calculation for you. If not do one yourself using the spreadsheet at http://www.buildmyowncabin.com/electrical/residentialloadcalc.xls. How you decide to handle the brewery load will be a major swinger as a 50 Amp circuit is 1/4 of a 200 Amp service and if you count it as a 100% demand factor load can easily push you over 200 A if you are heating with heat pumps with electric backup. OTOH if you are heating with gas or oil you may well be under 200A even with this load counted as 100%.

Obviously it isn't a 100% load by a long shot but what is it? I believe it should be counted, for the purposes of sizing service, as a 75% load but would have to dig into the NEC to confirm that.

I strongly recommend playing around with that spreadsheet as you will gain insight as to what the consequences of you equipment choices are just as playing around with a brewing spreadsheet gives you insight into the consequences of your grain choices.

 

[lschiavo]

Obviously it isn't a 100% load by a long shot but what is it? I believe it should be counted, for the purposes of sizing service, as a 75% load but would have to dig into the NEC to confirm that.

I would probably include it as an electric range/oven. If you have other Electric cooking appliances, it will be derated based on the total number of appliances.

 

[itsnotrequired]

i would be amazed if a place in kansas city had only electric heat. even with an electric water heater, 200 amp should be plenty for a 2700 sf home, provided they aren't running an electric kiln or greenhouse or some other unusual residential load. i have about 3700 sf finished at my place with a 200 amp service. electric oven and clothes dryer, plus an electric sauna and the brewing system. i haven't batted an eye during brewing, even in the summer when the a/c is jamming. i suppose if i was brewing, drying clothes, someone was taking a sauna and baking a turkey in summer with the a/c on as well as all the lights, maybe there would be an issue but let's get real here...

 

[ajdelange]

I feel somewhat as if I am beating a dead horse here but what he has to do does not depend on what would amaze any of you or exceed your personal feelings as to how services should be sized or how big your houses and panels are (though information on this is useful for insight and interesting). What he needs to do is size the service such that it will get past the permitting process, the utility and ultimately the inspector. Clearly whoever pulls the permit should do the calculations but I still encourage OP to use the spreadsheet mentioned in #44, be he the guy that pulls the permit or no, to get some idea of how the choices he makes may influence the required size of the service. To anyone reading this who decides to try the spreadsheet I'll mention that when the pop-up instructions and labels refer to 'Column C' that does not mean column C of the spreadsheet but rather column C of table 220.55.

"Amazing" things do happen, especially when we stick 50A circuits for brewing (or whatever) in our houses. I have mentioned that I have a house which is, I'm sure, under 4000 ft^2 that has 600A service. When I was told that I needed 600A service I was indeed amazed. But I just did a load calculation for the place and per code the load is 477 amps. This is because there are 2 heat pumps one of which is backed up by electric, electric space heaters in an out building and in the old part of the house and (3) 50A outlets. Interestingly enough I can now prove to the satisfaction of the NEC based on actual load measurements that my required service size is 400A which common sense dictated from the start. But the rules are the rules and we have to follow the rules.

 

[itsnotrequired]

don't get me wrong, i'm not advocating 'winging it' or using personal preferences to size a service. whatever it takes to get the permit is what it takes. the nec is straightforward for most of sizing a service (e.g. lighting load, laundry load, small appliance branch circuit, etc.) but is a little vague in others. and this is intentional, it is simply not feasible to dictate clear direction for every possible installation out there. a classic example is the requirements of 220.14(C), which dictate how motors need to be accounted for. for example, i have a 30 gal aquarium with a little pump in it, clearly a motor. it is plugged into one of the general receptacles in my living room. do i need to include that 'motor' as a stand-alone item in the calc? or since it is plugged into a general receptacle, is the load already accounted for in the 220.14(J) allowances? there are dozens of little nuances like this and can result in fairly decent swings in what the service size calcs out to be. when in doubt, get your electrician involved and they will tell you what you need.

also a couple issues with that spreadsheet. first one i noticed is the general lighting load calc. yeah, load is 3 va per sf but that is only a 100% demand factor up to 3000 sf. above that (up to 120,000 sf), lighting load is calculated at a 35% demand factor (or 1.05 va per sf). spreadsheet doesn't account for this, will make the service appear to be larger than required. i don't deal with residential electrical permitting that often but i can't say i recall a permitting authority asking for loads like mini fridges and non-fixed microwaves needing to be specifically included in service calcs. not an inherent problem to include them but this likely inflates the load to be greater than what code would typically require.

tl dr, but to the op, mention to the electrician your brew system, the load and how you plan to use it. more than likely, they are already planning on a 200 amp service at a minimum and aside from other wild electrical loads, you should be fine.

 

[ajdelange]

it is simply not feasible to dictate clear direction for every possible installation out there.

So what do you (the NFPA) do in a case like this? Be very conservative and that's what they do. In the case of my house up north and based on three months history of load including a darn cold December, the max I drew was 140 A and yet the spreadsheet tells me that for purposes of sizing the service my load is 428 A (without the 3 50A outlets) and I need 600A service. The historical data, if I try to fit a probability distribution function to it which I have done as shown in earlier posts, suggest that the probability of a load bigger than 400A is about 10^-18. To put this in perspective the universe is estimated to be 4.35495e+17 seconds old. The expected number of events at this probability level in the entire history of the universe is, thus, less than 1. To put it in perspective another way, if I gave you 60 pennies, told you that a particular sequence (HTTHHTHTTTH.....) spelled the end of the world and had you flip the coins the probability that you would arrive at the disaster sequence would be about 10^-18. But it's not 0! (that's an exclamation point - not a factorial sign). On your first try you would come up with some sequence other than the disaster one. It has the same probability of occurring as the doomsday sequence (10^-18) but it did occur.

also a couple issues with that spreadsheet. first one i noticed is the general lighting load calc. yeah, load is 3 va per sf but that is only a 100% demand factor up to 3000 sf. above that (up to 120,000 sf), lighting load is calculated at a 35% demand factor (or 1.05 va per sf). spreadsheet doesn't account for this, will make the service appear to be larger than required.

In fact it does handle this correctly. The issue I have with it is that it does not make this at all clear. Enter 1000 ft^2 in the square footage cell and note that the load indicated 3 kVA. Also not the service load in the summary box. Now increase the floor area by 1000 ft^2. The General Lighting Load cell goes up by 3000VA but the service load box by only 1050 which is 35% of 3000.

 

[itsnotrequired]

so if i understand correctly, the likelihood of you exceeding 400 amps is very small but you did exceed it. my counter would be...so what? worst case scenario is the main trips and you reset it (would suck if you have fuses). is it worth being ultra-conservative for that one event? i would say no but that's me. i guess what i am trying to say to the op is that if the electrician suggests a 200 amp service, no need to believe he is some kind of quack and press him hard for the 400 amp. who knows what electric demands will be 30 years from now so feel free to go bigger but in my opinion, no need to feel like you are rolling the dice on a 200 amp service.

i took a closer look at that spreadsheet and you are correct, it does account for it. not super-obvious but it is there. my other commentary about mini fridges and the like still apply.

 

[doug293cz]

OT question for the code wonks: How do the super efficient LED lamps affect the lighting load assumptions? Or, is the code behind the times? I have swapped out all the incandescent lamps in my house for mostly LED, and maybe a few CF's.

Brew on

 

[itsnotrequired]

OT question for the code wonks: How do the super efficient LED lamps affect the lighting load assumptions? Or, is the code behind the times? I have swapped out all the incandescent lamps in my house for mostly LED, and maybe a few CF's.

Brew on

zilch. still need to size for 3 va per sf, even if you plan on using candles for light. after all, what's to prevent the owner of the home after you from pulling out their old incandescents and removing the leds? i'm sure code will catch up eventually but this is where we are at...

 

[ajdelange]

so if i understand correctly, the likelihood of you exceeding 400 amps is very small but you did exceed it. my counter would be...so what?

So what for sure as I have 600A service.

worst case scenario is the main trips and you reset it (would suck if you have fuses).

I do but at least the main disconnect is indoors at that house.

is it worth being ultra-conservative for that one event?

Remember that I wanted 400 Amp service but was forced into 600 by the electrician and utility and the fact that I was not there to yell and scream when this industrial scale gear was installed. The amazing thing about Quebec (actually, there are many amazing things about it is that they don't seem to have inspectors. The insurance companies seem to assume their role.

i would say no but that's me.

I was really more concerned about whether a 200 Amp generator was sufficient. Measurements show that it is though the probability of going over 200 amps and having to shed a load is much greater (10^-8 -still very small) [/QUOTE]

i guess what i am trying to say to the op is that if the electrician suggests a 200 amp service, no need to believe he is some kind of quack

Based on my experiences with electricians I can't agree. What we are really talking about here is engineering the electrical system and electricians aren't engineers. Now admittedly I did some unusual stuff which was beyond the experience of those electricians but they have worked on some amazing places up there. I've also had electricians here who claimed to have worked on the CIA's new building but couldn't read a one-line diagram.

and press him hard for the 400 amp.

I'd want to qualify the electrician somehow. If OP isn't an engineer I can only suggest hiring one (I know - more $) and perhaps with the scope of his project it isn't worth it.

who knows what electric demands will be 30 years from now so feel free to go bigger but in my opinion, no need to feel like you are rolling the dice on a 200 amp service.

That's a very good point. It isn't that big a deal to upgrade a service really. Yes, you will save some money in the long run if you oversize now but OTOH you may never expand.

i took a closer look at that spreadsheet and you are correct, it does account for it. not super-obvious but it is there. my other commentary about mini fridges and the like still apply.

As you pointed out the code itself allows more than one interpretation in such cases. We can hardly expect the spreadsheet to do better.

 

[itsnotrequired]

of course, if the utility, jurisdiction, etc. says you can't put in smaller than a size 'x' service, then that's what will be required. assuming 'normal' electrical loads (brewery included), a home of the op size in his geographic location should be fine with a 200 amp service. that's all i'm getting at. any electrician worth a lick is more than qualified to size a service, they don't need to be licensed professional engineer.

you surely must realize that your 600 amp service is an extreme outlier. can't say i've ever seen a 600 amp service at a residence, save some giant mansion or some other extreme electrical situation.

 

[ajdelange]

Wish I could share your confidence in electricians. I finally found one that is indeed "worth a lick" and even he had to have the service entrance requirement explained to him. What sets him apart from the crowd is that he listens.

I realized from day one that 600 amps was too big but was told by the electrician and utility that I had to have it. If the utility says they won't provide 400 amp service to you you take 600 (there's an old story about onion soup). Now the house does have lots and lots of outlets, two heat pumps, 5 electric space heaters, electric backup for one of the heat pumps two laundries, two electric driers and (3) 50 amp outlets sewage ejector pump, and well pump and if you put those into the NEC algorithm, especially the standard algorithm, you go over 400A. But if you look at the actual loads the rule is that you must size for 125% of the maximum average 15 minute load plus whatever you plan to add. So if I went in and said I wanted to add a hot tub that drew 25A my service requirement would be 122.7 (max 15 min avg load) + 25 = 147.7 so I would have been OK with the original 200A service that was there even before I added on. What this proves, if anything, is that my family's use of electricity is not consistent with the NECs assumptions. Our load factors are much less, There aren't as many of us as the NEC assumes there are per square foot, per clothes dryer etc. Another factor is that all the lighting in the new part is LED and tungsten in the old part has been replaced by LED when ever one burns out so the lighting load that goes into the NEC calculation is too large.

 

[itsnotrequired]

that 3 va per sf lighting load also includes general-use receptacles, that is why it may appear large.

 

[ajdelange]

OT question for the code wonks: How do the super efficient LED lamps affect the lighting load assumptions? Or, is the code behind the times? I have swapped out all the incandescent lamps in my house for mostly LED, and maybe a few CF's.

As noted, no provision is made. At first blush it would seem that the code is simply behind the times on this but after a little thought it occurred to me that LEDs and CFs impose an additional 'load' on the utility's equipment and that is a current load at 180, 300,420...Hz. The eddy currents induced by these frequencies result in greater heating of transformers and some other equipment and so gear for a say, a 50 kVa load would need to be sized at greater than 50 kVa if these harmonics are present. THD (the percentage of total current which is harmonic current) at my house in Virginia runs 10 - 20% most of the time but can spike much higher for some loads (I don't know what they are but am guessing its when rooms with large numbers of CF lamps or LED lights are switched on). This is definitely considered in industrial settings (I have had to certify that equipment going into a government facility had to have a harmonic current draw less than some percent) but is not, AFAIK, at issue for residences - yet.

 

[ajdelange]

Most homes now have a 50a 240v plug behind the stove whether is gas or electric...

Forgot that I also have one of those so that makes the count 50A x 4 - none of which are in current use.