Upgrading pool subpanel for second pump

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Old 02-06-09, 10:39 AM
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Question Upgrading pool subpanel for second pump

I have a 20 amp 2 pole breaker in my main panel in the garage that goes to a timer/distribution sub-panel for my pool pump and pool lighting on the back of my house. In the box by the pool equipment there is a 2 pole 15 amp breaker going to the current pool pump and a single pole 15 amp going to the pool lignting. I would like to add another breaker to the pool box for a second pump for a water feature. It is a 2 hp pump and I ran #12 wire to the new pump. I think that I should add a 2 pole 20 amp breaker for the new pump. I want to add the new breaker to the current pool sub-panel where there is room to do so.

In order to upgrade the wire from the main panel that has a 20 amp 2 pole breaker in order to supply the extra current for the new pump, I am planning to change out the 20 amp for a 40 amp breaker, and run a new heavier wire from the new breaker to the pool panel. I am doing this because there is no room in the main panel for another breaker. Otherwise, I would have just added an additional breaker and new circuit wire to the new pump and leave the pool box alone.

Is the 40 amp breaker the proper upgrade and should the new wire be #8 or #10.
 
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Old 02-06-09, 10:56 AM
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The wire must be #8 for a 40a breaker and you can not use NM or UF cable because code requires an insulated ground to a swimming pool. THWN in conduit is probably the best way. AWG 10 would need a 30 amp breaker but with out knowing actual loads it would be impossible to say if that would be enough.
 
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Old 02-06-09, 11:58 AM
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What size conduit do you have between the main panel and pool panel? You will need at least 3/4" to perform this upgrade. If you only have 1/2", please post back as you may be able to squeak by with a 30A feeder but we will need to know the exact specs of the pumps and lights.

If the new pump is a 240V 2HP, it requires either a 15A double-pole GFCI breaker or a 20A double-pole GFCI breaker. I would probably go with the 20A to allow for sufficient starting current. That breaker will probably require you to go to a supply house -- big box stores don't stock that item.

The new pump will also need to be bonded to the existing bonding grid using approved brass clamps and solid #8 copper wire.

The existing #12 conductors in your conduit need to be replaced with three #8 copper THWN (black,red,white) and one #10 copper (green insulated, not bare).

The breaker feeding the pool panel can then be increased to 40A.
 
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Old 02-06-09, 01:29 PM
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Ray:

I thought that I'd go with 40amp to leave room for a little expansion in the Pool panel. I already ran 4 #12 wires through 1" conduit (THWN) and wired 3 to the pump 230v 2hp. The motor says 22/11 which I was told means 22amps 115v/11amps 230v. So, I think I'm good there. I do have 3 #14 wires in there for 115v convenience outlet at the pump location. I was going to just take off one leg plus neutral for the 115v but thought that it better to run another circuit dedicated to the 115v.

With regard to the total load at the pool panel, there is a 2hp 230v pump and a relatively low amperage 12v xformer for the lights. Each is on its own breaker in the pool panel, 2 pole 15amp and 1 pole 15amp respectively. I bought a 40amp breaker for my main panel to replace the 20amp already installed and I know that I can't use the same sub-panel feed wire so I'm going to replace it with the #8 to the pool sub-panel. I needed someone like yourself to chime in to see if I'm on the right track with the whole scheme.
 
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Old 02-06-09, 02:08 PM
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Ben:

As you can see in my post to Ray, I'm running #12 to the new pump. I used 3/4" conduit for the new pump. I have not yet run the #8 to from the main panel to the pool sub-panel. I thought I'd run #8 romex if there is such an animal. All of the cable in the house is romex from point to point as well as the present sub-panel feed from the 20amp breaker currently in the main panel. I am upgrading the breaker to 40 amp 2 pole, as mentioned, so I'll run a new sub-panel feed and use the old sub-panel feed for the new 115v convenience outlet that I told Ray about. I did buy a breaker to put in the pool sub-panel for the new pump (2hp - 11amp on #12). The new breaker is a 2 pole 20amp because I wired it with #12 and thought that your supposed to have a 20amp breaker on #12. Maybe, that was not correct if I'm only drawing 11 amps with the new pump.

I'm not clear on your comment about the wire between the main and the pool sub-panel. I'll be trying to run #8-2 plus a ground romex. If there is a romex with #8-3 plus ground then that would work from the main panel to the sub-panel, right? Thinking out load, I could run a 3/4" conduit as suggested instead, from the garage to the back of the house through the attic much easier than the romex because I can just push it across open area to the other side. After I do that you say I should run 3 #8 THWN and a #10 ground. but it is in the attic so that it doesn't need to be THWN, right? I can suck a pull string through the conduit and pull the 4 wires easier than pulling romex, actually. The only part of the run that is outside would be coming out of the overhang down the wall to the pool sub-panel. Will it still have to be THWN?

By the way, guys. It sure is much easier going at this with more heads in the mix. At least I have gained the confidence that I'm generally on the right track with my pre-plan. I am really greatful for your input.

Denny
 
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Old 02-06-09, 02:47 PM
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Originally Posted by CyberDude View Post
I'd run #8 romex if there is such an animal.
You can get #8/3g Romex (NM-B cable), but it can only be used for pool equipment if the cable is run entirely inside the house. If it goes outdoors, underground or along the outside of the house then you cannot use Romex and instead must use THWN in conduit.

thought that your supposed to have a 20amp breaker on #12. Maybe, that was not correct if I'm only drawing 11 amps with the new pump.
The rules for breaker sizing on motors are different than those used for other types of circuits. A breaker for a motor can up up to 200% of the running current of the motor. With your new pump, the running current is 11A so you could use a 15A or a 20A breaker.

Does this water fountain pump attach to the pool? If so, the breaker will need to be GFCI and the pump will need to be bonded.

I'll be trying to run #8-2 plus a ground romex. If there is a romex with #8-3 plus ground then that would work from the main panel to the sub-panel, right?
#8-2g is incorrect. The wiring must be #8-3g as the neutral conductor is required.

I could run a 3/4" conduit as suggested instead...The only part of the run that is outside would be coming out of the overhang down the wall to the pool sub-panel. Will it still have to be THWN?
This depends on how much of a stickler your electrical inspector is. The code does specifically say that NM-B cable is allowed only on the "interior" of the building when used for a pool circuit. But there is usually some leeway in allowing a few inches of Romex to poke through a nipple through the wall into the back of a panel mounted on the outside of the wall.
 
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Old 02-06-09, 03:12 PM
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Thanks for the quick response. I'm sorry if you thought that I would run any romex along the outside of the wall. I would not do so and instead run the 3-4 feet of romex into a 1" conduit coming out of the soffit along the outside wall as I have all others.

I will run a 2 pole 20amp for the pump as per your suggestion due to the startup current as described. The water feature draws water from my pool and pumps it to a waterfall that spills back into the pool, so I guess the answer is yes to your query whether it is attached to the pool. Right now I have L1 and L2 on the motor as well as a green ground wire attached to the grounding lug on the motor case. I also tied that to the bare ground wire that travels through the conduit with the romex 2-14 plus ground for the 115v convenience outlet.

As I eluded, I think the conduit with 3-#8 and 1 #10 green will be easier to run than the romex. However, I was going to get away with local builder's supply house wire which is not designated as THWN. It will be in conduit from the soffit to the pool sub-panel for about 3-4 feet on the wall.

A question about the bonding statement: The pump's white and black wire (L1 - L2) will be wired to the 2 poles of the breaker. The green wire, which is on the motor case lug will be wired in the sub-panel to a ground bar as the pool pump currently wired. Will that provide the bonding you are speaking of?
 
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Old 02-06-09, 07:51 PM
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Originally Posted by CyberDude View Post
The water feature draws water from my pool and pumps it to a waterfall that spills back into the pool, so I guess the answer is yes to your query whether it is attached to the pool.
In that case, the breaker must be GFCI. Probably a supply house and/or special order item.

However, I was going to get away with local builder's supply house wire which is not designated as THWN.
THWN is not the only type of rating that would be acceptable, but it is the most common one. The most important parts are that the wire must be rated to at least 75 degrees (H) and be waterproof (W). Most THHN is dual rated THWN if you look at the fine print on the wire.

It will be in conduit from the soffit to the pool sub-panel for about 3-4 feet on the wall.
Is that where the main panel is? Individual conductors must be enclosed in conduit for the entire run from panel to panel. Or you can transition from #8/3g romex to THWN in conduit inside a permanently accessible junction box inside the building.

Will that provide the bonding you are speaking of?
No. Bonding is done on the bonding lug mounted to the outer frame of the motor. If a bonding lug was not provided by the manufacturer, you can buy an aftermarket lug. The lug must then be connected to the existing bonding grid using a solid #8 copper wire and a brass clamp which is listed for pool equipment bonding. The existing bonding grid should attach to any metal surfaces around the pool including at the very least the existing pump and rebar in the concrete pool deck.
 
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Old 02-07-09, 09:59 AM
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Thanks, Ben for all your help. Today is the day I finish all of the aforementioned. The green wire that follows in the conduit to the pump is connected to the case of the pump on a ground lug. I will be running conduit from the main panel in the garage through the attic to the back of the house and down the back wall to the pool sub-panel for the sub-panel service upgrade and the wire will be THWN #8 for 3 wires and a #10 ground.

As for the bonding that you explained my pool pump has such a grounding arrangment so I'll be running a 6' copper bar into the ground at the new pump and grounding it to the new pump.

I appreciate all of your help.Beer 4U2
 
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