Help me design my new 240gal setup!

[Slickdonkey]

Electrical considerations

Ok, first off let me say this post is about electrical installations, and doesn't really talk about anything reef-related at all, so if this kind of thing doesn't interest you, be forewarned!

I estimate with all my equipment running I could draw close to 27 amps mid-day with all the lights on. Wow, that's quite a bit of juice. So my latest step in setting up this monster tank involves the installation of new electrical outlets. In fact, I figured on adding three 15-amp circuits. I chose this because it gives me some wiggle room as well as capacity for new equipment and overhead for motors startups on the pumps and chillers. I'll probably use one circuit for the chiller and heaters, one for the lights, and the other for the pumps and other miscellaneous equipment.

I know 20-amp outlets are common, but I chose three 15's instead of say two 20's for two reasons:
- I figure it's better to have more circuits of a smaller capacity rather than fewer with larger capacity. In case the breaker trips for some reason, less equipment will be affected if it's spread out over more circuits.
- My electrical panel is pretty darn full of 20-amp circuits already (see pictures below), and using a 15-amp circuit makes me feel better about my rapidly rising total. I have 200 amp service to my home.

The plan is to route three wires (14/2, about 90 feet each) to the crawlspace under the floor where I'll have my equipment set up. Should be a matter of just running the wires, popping in some new circuit breakers and I'll be ready to go, right? Well, with this project nothing is ever so easy, as you should know by now. I popped open my electrical panel...
View attachment 11444

Uh oh... I don't see much real estate in here. Come to think of it, when I installed that air compressor circuit last year I remember thinking "man, this panel is so full, I'm glad I don't plan on adding any more circuits in the future!". Hmmm.

I figured the best bet is going to be to install a subpanel. This is more work, but it gives me the flexibility I'll need to add my new circuits, and will prevent this very problem from happening again in the future if I decide to get a monster hot tub for the back deck or something.

Now I'm not an electrician, but I have done some basic electrical work and I work with low-voltage electronics as part of my job, so how hard could it be? I thought I'd take a stab at it and save myself a few bucks. If I just remember to respect electricity, it will respect me. Keep my tongue and fingers off the hot buses and I should be fine. I also enjoy learning these sorts of things. The knowledge may be useful in the future, and besides, family and friends will think I'm smart. As long as I don't kill myself. Then they may have a different opinion.

In most locales you're supposed to get a permit for this. I am unincorporated so have to get it from the county. I thought of another option to save a few bucks and got mine on eBay:
View attachment 11445

 

[Slickdonkey]

Installing the subpanel

A subpanel is pretty simple, in a nutshell all you have to do is install a breaker in the main panel and run the wire to the subpanel and you're good to go. Sounds easy, but this took a fair amount of work in my situation. I chose to use a double-pole breaker to run 240V to my subpanel. I won't need 240V for this project but I might in the future, and besides, the oven that I'm moving to the subpanel will need it. It isn't any more difficult.

First of all, if you take a look at the picture of my main panel above, there's no room for the aforementioned breaker. Something's going to have to be pulled out and moved to the subpanel to make room for the subfeed. I chose the electric oven, which is the 30 amp double-pole breaker on the top left. As an added bonus I can replace this 2" thick breaker with one of the newer 1" breakers and save some space in the subpanel.

By the way, notice my main panel is one of the older split bus panels (probably original from 1975) and the main breaker is the 70 amp, second down from the top right. I decided to leave the power on to the house while working on this project, because as you can see there really is no main cutoff from the utility inlet. So the busses are still going to be hot regardless. I *think* on the newer panels you can use the main breaker to cut the power to the busses, which is certainly a good idea. Oh, and also my wife was having a party inside so I don't think cutting the power would have gone over well. I just have to be extra careful not to poke my fingers in the wrong holes or it will scramble my brains and I won't be able to finish the project! I guess you're not really in suspense because as you can tell I didn't die.

So, the first thing I did is to turn off the breaker for the oven, pull it out, and hang the subpanel on the wall next to the main panel. As an alternative I could have put the subpanel down in the crawlspace, but that's inconvenient if I decide to ever add circuits for anything other than reef equipment. This also would mean a 90-foot run of some really expensive thick cable (more on that below).

Here's a picture of the main panel minus my oven breaker and the subpanel hanging next to the main.
View attachment 11449View attachment 11448

You can see the 14/2 white wires next to it which I ran through my garage and into the crawlsapce. This involved some measuring, barely missing my cold water line while drilling a hole, and hitting my head on the floor supports a few times, but otherwise was not difficult. Good thing I missed the water line or you'd be reading about plumbing as well.

My main panel is a GE panel, so I bought a GE subpanel as well. You don't have to, but this gives me some extra flexibility if I ever want to move things back and forth between the panels. Panels by different companies use different sized breakers, of course. I always see GE breakers in the hardware stores, so I don't think I'll have any trouble finding them for future expansion. This can be a problem with some of the off-brands (i.e. some stores carry only certain brands, but I almost always see GE).

 

[Slickdonkey]

Routing the wires

The subpanel I bought is rated for 125 amps, so I decided I was going to feed it as though it was fully loaded. I don't think this will ever happen, but I figured I should plan for it now and not have to do anything to it later. If I were to do it again I think I would be less conservative and just go 80 to 100 amps. For one, the 125-amp breaker is expensive. It cost $56, and the 100 amp breakers are only $22. There is an exponential curve on price as these things get bigger. The other reason is that the wires rated for 125 amps (at 6 feet) are expensive, HUGE, and difficult to work with. They're so stiff that it's hard to bend them into the shape you want.

Check it out, I tried to get a picture of my thumb for comparison. There are three conductors plus the ground. This is 1/3 aluminium service entrance wire. I had to go to a contractor supply store to get this, and it was $16 for 6 feet. I would have preferred to use copper wire, but this was even more difficult to find, and you have to use a thicker gauge. I'm not sure why this is, but that's what everyone was telling me.
View attachment 11450

I stripped the wire with my razor blade (I don't have any wire strippers big enough) and scrubbed it down with a wire brush. This gets rid of little pieces of insulation I might have missed and gives the wire a nice shine.
View attachment 11452

I read that aluminium wire was used for home wiring when there was a copper shortage in the 1960's and 70's. Over time it would oxidize, deteriorate, and turn into a fire hazard. To prevent this, you can coat the wire and terminals with an anti-oxidant compound.
View attachment 11451

So, I attached the wire to the subpanel. The black and black-red striped wires connect to the main lugs, the white-striped wire to the neutral bar, and... did you notice anything missing in the subpanel picture above? Yes, there is no ground bar (which is where the bare ground wire attaches to). I had to go purchase this extra and attach it to the panel (on the left). The neutral bar is on the right. In a subpanel, the neutral bar and ground bar must be isolated from eachother. This also means the neutral bar is not connected to the subpanel chassis (sometimes there is a screw you need to remove, and you can see the neutral bar is insulated by plastic standoffs). By code, the ground and neutral should only be bound together in the main panel. I can't remember why this is, but it's the correct way to do it. Someone explained it to me once, but I've since forgotten. In any case, this is important for safety.
View attachment 11453

 

[Slickdonkey]

Wiring, continued

Once this was done, I routed the huge cable through a 1-1/4" hole in the stud and into the main panel. This was by far the worst part of the job. As you can see, my main panel is a real rat's nest of wires and there wasn't much room to run this huge thick cable up through the wires to the top of the panel where the oven breaker used to be. Much swearing and cursing was involved. It's also a little nerve-wracking because it is necessary to stick your hand in there and move these wires out of the way to make room. And sticking my hand into a live electrical panel and shoving things around just screams for a Darwin-award nomination. Tiffany was standing by with her finger on 911.

In the end I got everything to fit. I didn't have any wire-cutters big enough to trim these conductors, so I used Tiffany's pruning shears when she wasn't looking. Then, just attach the wires to the new 125-amp breaker and put it in. It looks so easy. The neutral and ground wire are circled where they connect to the ground bar.
View attachment 11459View attachment 11455View attachment 11456

 

[Slickdonkey]

Finishing the subpanel

For my final trick, I routed the wires for the oven into the subpanel and attached them to the new 30 amp breaker. Note that the double-pole 240V breakers (my oven is 240V) need to be located such that the breaker spans both hot busses (the white metal pieces). House wiring basically has two 120V feeds, and you can add them together to get 240V. That's what's going on here.
View attachment 11457

After this was done I flipped the subpanel breaker on in the main panel and used my voltmeter to verify I was actually getting 240V across the busses. Then I flipped on the oven breaker. Looks like all was well, so I shut off the subpanel again and finished hooking up my three reef tank circuits like you would any other circuit. I left these off when I powered up the panel, because the wires are still dangling in the crawlspace until I figure out where exactly I want to put the outlets. I'll probably know for sure once the sump is in its final resting place.

Here's the completed work:
View attachment 11458

I hope this was interesting and maybe informative. As I mentioned I'm not an electrician, so if you spot any errors in my installation please drop me a note!

 

[Scooterman]

Man your box is full lol, I would of use 12/2 for the distance just to reduce the voltage drop even though it may not be much. Nice documentation man great work.

 

[Slickdonkey]

Yeah, I chose 14/2 because it's rated up to 100' for 15 amps. In retrospect I probably should have used 12/2, but I don't expect to be drawing the full 15 amps on each circuit either.

Yes, the box is full, but a lot of these circuits are "extras", like a bathroom space heater, dishwasher, garbage disposal, air compressor, and other stuff that is usually not running but has dedicated circuits. So it's not "really" that full, I tell myself!

 

[jsmkmavity]

if you want to "upgrade" your sump in the future you could use a spray or brush/roller applied sealer on ply wood or even a hole in the ground! theres a thread on that here somewhere! diy something or other! good luck and have fun!

 

[LakeEd]

Continue giving us these awesome updates Brian!!!

THANKY!!!!

 

[Slickdonkey]

You bet, hopefully someone will learn something. Actually I should have posted the electrical stuff in the DIY section and linked to it from here... but... oh well.

I just realized last night that after I do the closed-loop plumbing and reinforce my floor, it will be time to move the tank into the living room. Never thought the day would come. Well, it hasn't yet, but... I'm closer!

 

[Scooterman]

I think your doing fine by keeping it all posted here, keep up the good work! Really very seldom anyone would run everything all at once in a house, more so start everything at the exact time.

 

[Slickdonkey]

I think your doing fine by keeping it all posted here, keep up the good work! Really very seldom anyone would run everything all at once in a house, more so start everything at the exact time.

Well, there was that one time I was sitting in the jacuzzi tub with the space heater running, the dishwater going, and I was throwing banana peels into the garbage disposal while running my air compressor to blow bubbles in the tub.

But there will be no more of this kind of fun in my house.

Technically I think you're supposed to have an electrician do a load analysis... or maybe I could turn on every circuit in the house and use a clamp meter to see how much current I can draw.

 

[bc_slc]

wow. as someone who knows NOTHING about electricity, you did a great job of documenting how you did it. Man, how do you have so much time? A project like that would have taken me 2 months to do. It would have been partially completed, tools lying around everywhere...basically just asking my wife to kill me. Check that, you actually completed TWO tasks in that time period if you include making your sump as well. Wow, nice job.

Mat

 

[Slickdonkey]

Hah, well, I know enough about electricity to keep my tongue out of the panel. As for the rest of it, some internet research, a wiring book, and confirming every purchase with the guy in the electrical department at the hardware store will go a long way. A good hardware store helps here...

The electrical panel installation took probably about five hours total. I found the time basically between 7pm and 2am. Anyone who knew what they were doing and chose a smaller wire size could have done it in two, I'll bet.

Routing the wires was easy but time consuming. That probably took another 3 hours.

 

[LakeEd]

Anyone who knew what they were doing and chose a smaller wire size could have done it in two, I'll bet.

ahhhh... but could that person of writen such a super right-up about it?!?!?! *grinz*

 

[Scooterman]

http://www.electrician.com/vd_calculator.html

Use this tool to check your voltage drop.

 

[Slickdonkey]

Hmmm, 8.5V drop for 14/2 vs 5.3V for 12/2 @ 15 amps. Not a big difference I guess. I do worry a bit about the stress on the chiller motor though.

 

[Scooterman]

http://www.elec-toolbox.com/calculators/voltdrop.htm

That is a big voltage drop, your talking more heat & shortened life of equipment. Measure your line voltage then subtract the drop, if your less than 115VAC I'd reconsider your wire size, I used 10 amps as a load basis, you may use 7 or 8 to consider the proper size unless you have the data on your equipment.

 

[sparky52]

Looks pretty good, just remember when using aluminum wire the aluminum wire is always larger than the same size copper wire due to coppers better conductivity, The nuetral/ground bond at the main panel only rule is to prevent setting up parallel ground paths. And remember for anything you are going to have on for longer than three hours you must increase the amp draw by 125% or you will overload the circuit..even if you dont trip the breaker you are still doing damage to its thermal magnetic guts and the wires insullation by constantly exposing them to temp. above their rating this is why lots of older wires you encounter are cracked and brittle. Also consider running two 12/3 or 14/3 cables this will give you four ciruits with only two cables and two nuetrals as the two phase conductors are out of phase with each other and thus can share a nuetral. Good luck..any ? send em my way

 

[Slickdonkey]

Thanks Sparky. Trying to get a handle on what you said here... when you say "increase the amp draw by 125%", do you mean if I have a 15 amp circuit I should choose the wire as though it were really 18.75?

That's a good idea about the cables; wish I'd thought of that before running the wires. Well, I still might do this if I end up going to a larger wire size. One thing though -- there is only one wire for neutral in the 12/3 cable so can you just jumper it from one outlet to the other?