[crisscross]

I have a 30 amp dedicated circuit to my grow space with 10/2 wiring

Off of this circuit I want to run these items:

2-600w ballasts on 1-intermatic timer
2-can fans for filters
1-8 port air pump
2-small air pumps with 2 hose outlets each
2-2' cfl tube lights at probably 30w each max
1-636 gph pump
1-1/4hp water chiller

will that be too much?

If so, I have an additional identical circuit that COULD (with quite a bit of work) be used to power some of those items. However, I already have a in wall a/c unit running on that circuit.

advice?

additional question: can 1 intermatic mechanical timer run a recepticle which has 2-600w ballasts plugged into it?

[burns1n209]

you should be fine, only thing im not sure of is the how many amps are pulled with a 1/4 chiller. if its only a couple then your good.

2nd question. yes it can 2 600w only pull 10-12 amps. you just want to get a 20amp receptacle.

[crisscross]

here's some info from aqua cave

* Capable of Chilling: 170 gallons - 10° F; 100 gallons - 30° F
* 480 Watt
* 120/60 V/HZ
* 4 Amps

other websites state 4 amps as well.

Every receptacle in the room is 20 amp.

[rives]

You do not want to run 20 amp receptacles on a 30 amp circuit. You could build a small distribution center with 15 or 20 amp breakers and feed it from the 30 amp circuit, and the load would probably be fine. It is too much for a 20 amp circuit - with ballast losses figured on the lights plus the chiller, you are already at 1800 watts (15 amps). The 80% rule states that you are only allowed to run 80% of the breaker rating for continuous loads (defined as any load over 3 hours in duration).

If you are talking about the Intermatic T-101, 103 family of timers, then yes, they can easily handle (2) 600s. If you are talking about the plug-in style, then no.

[crisscross]

Originally Posted by rives

You do not want to run 20 amp receptacles on a 30 amp circuit. You could build a small distribution center with 15 or 20 amp breakers and feed it from the 30 amp circuit, and the load would probably be fine. It is too much for a 20 amp circuit - with ballast losses figured on the lights plus the chiller, you are already at 1800 watts (15 amps). The 80% rule states that you are only allowed to run 80% of the breaker rating for continuous loads (defined as any load over 3 hours in duration).

Rives-

If you are talking about the Intermatic T-101, 103 family of timers, then yes, they can easily handle (2) 600s. If you are talking about the plug-in style, then no.

Hate to sound like a dummy but could you elaborate on 'distribution center' Would that be similar to a sub panel? Would I be better off just changing the breaker to 20 amp? Are you saying that a 30 amp circuit is too much power/create too much heat?

when you say I am at 80%/15 amps, you are basing that on a 20 amp circuit, right? how do you figure 1800 watts? 600w + 600w + 480w = 1680w I thought 80% of 2400 amps (derived from 20 amps @ 120 volts) is 1920 watts? Is my math correct? Probably not, that's why I'm here asking you.

The timer is the t101r so that's good.

How do I find the amount of watts consumed by a pump? My smaller pumps I can figure out from a website off petco but the larger pump has no brand indication. Is there a tool or something I can plug the pump or other appliances into in order to measure this figure?

Thanks for your help. I see your posts everywhere and you seem to know your stuff...and then some.

edit* If the distribution center is a subpanel, what can I run off of that box? Total # of breakers at 20 and/or 15 amp and total # of watts. Thanks again.

[rives]

Originally Posted by crisscross

Hate to sound like a dummy but could you elaborate on 'distribution center' Would that be similar to a sub panel? Would I be better off just changing the breaker to 20 amp? Are you saying that a 30 amp circuit is too much power/create too much heat?

Yes, a sub-panel is a distribution center. Changing the breaker would be the ticket if you are going to run 20 amp receptacles behind it. The circuit breaker needs to be sized to protect the lightest-rated component in the circuit, so you have to look at all of the downstream parts and make sure that they are rated for at least as much as the breaker that is supposed to be protecting them. The breaker limits the amount of power that can flow in the circuit, so everything has to be sized accordingly.

Originally Posted by crisscross

when you say I am at 80%/15 amps, you are basing that on a 20 amp circuit, right? how do you figure 1800 watts? 600w + 600w + 480w = 1680w I thought 80% of 2400 amps (derived from 20 amps @ 120 volts) is 1920 watts? Is my math correct? Probably not, that's why I'm here asking you.

I didn't say that you are at 80%, I was just relating the rule. If you have things that are running for longer than 3 hours (lights, for instance), they are considered a continuous load. If you have a 20 amp circuit, then you don't want to exceed 16 amps of the continuous-load components. For instance, on a 20 amp circuit, you could run 16 amps of lighting and have some pumps that are on intermittently also on the same circuit.

As far as the 1800 watts, I was estimating & including the ballast losses. The 600w rating is a nominal rating, and is for the lamp only. The ballasts themselves take power to operate, and depending on the ballast this can be another 5%-15%. I was assuming 10%, so that adds another 120 watts to the load, for a total of 1800 watts. Your math is correct. My point was that with just the lights and the chiller, you are already at 1800 watts and you had a whole string of additional equipment that you wanted to run.

Originally Posted by crisscross

How do I find the amount of watts consumed by a pump? My smaller pumps I can figure out from a website off petco but the larger pump has no brand indication. Is there a tool or something I can plug the pump or other appliances into in order to measure this figure?

You could get a Kill-A-Watt meter. You can just plug equipment into it and get a direct reading of the wattage, amperage, kwh for whatever time it is plugged in, etc. Very handy tool, and they are under $30. If the nameplate lists the amperage, multiply amps x volts = watts.

Originally Posted by crisscross

edit* If the distribution center is a subpanel, what can I run off of that box? Total # of breakers at 20 and/or 15 amp and total # of watts. Thanks again.

If you fed a small sub-panel with your existing 30 amp circuit (with a 30 amp rated receptacle and plug), and it is a 120 volt circuit, then you could run a total of 3600 watts of intermittent loads, or 2880 watts of continuous load with another 720 watts of intermittent load. You could have as many breakers as would fit in the panel, but you would need to keep the total load under the above wattages. The breaker back at the main panel (the 30 amp breaker) determines the total load available.

Each individual 15 amp breaker could handle 1800 watts of intermittent load or 1440 watts of continuous load, and the 20 amp breakers could have 2400 watts of intermittent load or 1920 watts of continuous load. For instance, you could put each of your lights on their own dedicated 15a breaker, the chiller on it's own 15a breaker, and the rest of the gear on another 15a breaker. As long as you keep your total connected load within the limits of the 30a breaker, you're fine.

I know this gets confusing. If this isn't clear, ask away!

[crisscross]

Rives: I love the detailed response. You umm, rock.

I picked up a killawatt on my way home from work today. I just want to get one last thing straight: me putting 2-20 amp receptacles on a 30 amp circuit would do what exactly? I am NOT going to use it, I'm just curious as to worst case scenario and likely scenario. Thanks.

[OrganicBuds]

When equated to water:

Voltage is like the size of your water pipe.

Amperage is like the force behind the water.

If your amperage is too high, it will blow your "water pipe". AKA, it will overload yo.

Hope this helps.

[cravin morehead]

baba-booey, baba-booey, Howard Sterns penis....

[rives]

Originally Posted by crisscross

Rives: I love the detailed response. You umm, rock.

I picked up a killawatt on my way home from work today. I just want to get one last thing straight: me putting 2-20 amp receptacles on a 30 amp circuit would do what exactly? I am NOT going to use it, I'm just curious as to worst case scenario and likely scenario. Thanks.

Twenty amp receptacles are only built to carry that much power. If you run them on a 30a circuit, the power doesn't get magically divided between the two - either one could get the full 30 amps if the internal resistance of whatever was plugged into them allowed it, or if there was a wiring fault.

Additionally, there is a time/current curve that determines how quickly the breaker will respond. A brand new, completely in spec breaker can take 500 seconds to trip at 150% loading, and 100 seconds at 200% loading. So, you could easily put 60 amps through one of your 20 amp rated receptacles for nearly 2 minutes if your breaker met brand-new specifications. Great recipe for a fire.