[crisscross]

Hey everyone! I'm a noob as a member but I have been reading these forums for quite some time now. I have a question regarding electricity and if I should add an additional circuit or what?

I am going to do a closet grow with a dwc bucket (airpump only) with as 600w switchable ballast running 400w bulbs (I don't think bulbs matter but just in case I'm throwing that in there). I will be adding a can fan soon also.
On that same circuit is my office equipment: fax, printer, router, modem, display, tower and shredder. My concern is if I will be exceeding the amps that this particular circuit is rated for. It's a 15 amp circuit. I COULD install another circuit but because this area will be used for growing less than 3 runs before I expand I don't want to do much permanent work when it's a temporary job.

Do I look at the amp ratings on each appliance, add those up and make sure that the sum is less than 12 amps total? Or is there something else I should look for? Thanks for all the help!

[NiteTiger]

Yeah, add all your amps and look at the total. If you're close, there's no major issue in bumping your breaker up to a 20 amp. I doubt you'd trip under normal circumstances even with a 15amp, but you've got a motor in the mix.

Never an issue until your tie gets sucked into the shredder, spiking those amps as it shreds your best silk Then your breaker trips, and now when the fire department comes to rescue you from Strangle Shredder, it becomes obvious your shredder was a DEA drone

In all seriousness, isolate any sensitive electronics on that circuit. Sharing a circuit with surging high frequency transformers can make computers... unhappy :(

[rives]

Most of the equipment that you have listed has a pretty low current draw with the possible exception of the monitor and the tower. The best way to determine your existing load would be to pull the cover off of the panel and use a clamp-on ammeter on the lead at the breaker. I've had my equipment so long that I don't have a clue what an ammeter costs now. Adding up the loads will also work, you might want to kill the breaker and make sure that there aren't other loads on there that you are overlooking. Keep in mind that you want to stay at 80% or less of the rated current (the breaker rating), so stay under 12 amps on a 15 amp circuit.

*edit* Just read NT's post above after I posted. It is absolutely incorrect to state that there is no major issue in changing out your breaker - this can only be done if you have 12 gauge wire throughout the circuit.

[Crusader Rabbit]

See if you can find out the gauge wire used in this circuit. If it's 12 AWG, then you should be able to replace the 15 amp breaker with a 20 amp. If it's 14 AWG then 15 amps max. You're not going to run every appliance in your office at once, so you have some leeway here.

Depending on the hours you keep, you could run your grow lights during the times when you're less likely to be using the bigger energy draws in your office. My grow lights share a circuit with my washing machine. The grow lights come on at 8:00 PM and turn off at 9:00 AM, so I just have to remember not to do laundry till after 9:00 AM. Best of luck with this.

[NiteTiger]

By best practices standards, true. If you were designing a circuit for a 20amp grow, you'd gauge correctly.

However, in this temporary situation, increasing the breaker size to account fot a possible rare surge of current has no real world effect in the circuit. You even said it yourself, just like I did, he's not going to trip 15 as is. But, as I said, you have a motor on the circuit. If the motor bogs down, resistance goes up, amps spike. For the 30 seconds it takes the shredder to munch that phone book, he may spike over 15 amps. Maybe, although he's more likely to burn up the shredder.

By bumping up to a 20amp breaker, you step outside of the NEC and Best Practices manuals, yes. However, if you look deeper, you'll do the math on the line resistance (when you look at those numbers, realize line resistance is measured per 1000 ft) and realize that, in those few shredder seconds, the increased amperage running through those lines is insignificant in the real world. In other words, the wiring isn't going to burst into flames because of an extra couple of amps for a few seconds. Any short serious enough to cause heat issues is going to be more than a few amps, and trip the breaker as usual.

So, electrically, there is no real world problems with bumping the breaker up in this situation. In fact, there is no real reason to increase the breaker at all. The idea behind bumping the breaker isn't to allow for an excessive circuit in this case, its for security, unique to our profession. The larger breaker increases his security, knowing that if his wife/roommate/kid goes to shred their porn collection while he's gone, it doesn't compromise his security.

There is an inherent risk in our profession. The minute you get your seeds, you're opening the door to the possibility that men, skilled in combat, armed with automatic weapons, explosives, and armor will kick in your door. You can worry about codes inspectors if you prefer, but I worry about those guys.

Balancing the two, I prefer to maximize security, especially given the microscopic risks involved outside the code book.

Given those facts, what's the best answer? Codes say he pulls another 15amp circuit to use for the next three months. Math and logic say do nothing. Fear says install the 20 amp.

To clarify:

Do not design your grow using over-rated breakers. Long term grows should conform to best practices as closely as possible. Do not use over-rated breakers to continuously over-rate circuit currents.

Always err to security.

[rives]

You do not set your protection based on whatever you may have plugged into it at any given time, and pray that it remains healthy. If you like having things like valid insurance in case of a fire, you stay within the NEC. Protection is for worst-case scenarios, not "what can you get by with". As an electrician with 30+ years experience, I find your definition of security pretty bizarre.

[NiteTiger]

Originally Posted by rives

You do not set your protection based on whatever you may have plugged into it at any given time, and pray that it remains healthy. If you like having things like valid insurance in case of a fire, you stay within the NEC. Protection is for worst-case scenarios, not "what can you get by with".

You're right. Planning for future scenarios is a must in new installs. You do not assume what's going to be placed on that circuit, you rate the circuit safely.

However, in THIS CASE, we know the EXACT requirements of the circuit, over a specific period of time. Given that information, we can see the reality of the situation, and that reality says we can take an insignificant risk to maximize security in a temporary situation.

So your answer is what? Fish a new 15amp circuit to use for three months? Really?

Or do nothing?

Think about explosions in the night as your dragged at gunpoint to chains. Think about your wife's face as shes yanked from bed and manhandled.

Then put your damn code book down and install the 20amp breaker.

[rives]

Horseshit. With electrical, you either do it right or you don't do it at all. I guarantee you that there are a myriad of options available to fix his problem, if indeed he even has one, besides leaving a fire hazard behind for the next renter.

[NiteTiger]

Colorful phrasing aside, I didn't see your answer as to your recommendation?

Also, trying to carry the problem out to the future renters, what a crock. If he installs a larger breaker, obviously he swaps it back when he leaves. Just like he's not going to take down his lights. Please, the guy has enough sense to ask about amperage, and you assume he's stupid enough to leave as blatant a calling card as a swapped breaker?

Do you also advise people not install new locks on a rental because they'll break the lease?

Anyway, my position is clear, and I think I've reasoned it out well enough for someone to follow along. He's got the info you gave as well. He'll make his choice. Not gonna let this degrade into a pissing match.

[rives]

It is obvious from a number of your statements that you aren't an electrician. The issue that you don't seem to be grasping is that the breaker isn't there to protect specific items on the circuit - it is there to protect the circuit itself. There can be a fault anywhere else on the wiring being fed by that breaker, or in any device. Changing the breaker out would allow an additional 33% more current on the circuit than it is designed for. And, yes, I think that it is almost a dead certainty that changing the breaker back out would be overlooked in the turmoil of a move.

The NEC is a minimum. It is not meant to be some guideline for a cadillac installation that can arbitrarily be stripped down here and there to meet a budget or some other "imperative". As to your question about my suggestion.....the simplest thing that comes to mind if the shredder is the only issue would be to move it to another circuit - even if it is in another room, how often do you use a shredder? The shredder is a moot point, anyhow. If you look at the time/current trip curve for a breaker, the internal protection of the shredder is going to trip long before the breaker trips.

As I stated above, I find your definition of security pretty bizarre. I understand the desire to avoid the lights and sirens attached to police cars, but the ones attached to fire engines scare me even more.