Pool Subpanel

Reply

  #1  
Old 06-13-01, 08:15 PM
Visiting Guest
Posts: n/a
I want to install a supanel for my pool.

This is what I have to supply power to:

15amp filter pump
40amp max pool heat pump

Plan:

60amp GFCI breaker at main panel
~30ft #6/3 in PVC buried 18"
pool/spa subpanel box (sepatate neutral/ground bars)
40amp breaker #8/3 to Heat pump in flexible conduit
20amp breaker #12/3 to protected outlet for filter pump
grounding bar & #18 to bond filter/heat pump
The subpanel will be in close proximity to the heat pump to double as a disconnect.

Question:

Will this plan work? Is the one GFCI breaker at the main panel good enought to protect everything at the subpanel? What type of wire should I use(UF,THWN)?

Thanks
 
Sponsored Links
  #2  
Old 06-13-01, 09:50 PM
Wgoodrich
Visiting Guest
Posts: n/a
I take it that this is an inground pool then the following would apply;

You said;
15amp filter pump
40amp max pool heat pump

Reply;
This total amp load is not including any pool house wiring loads, or any pool cover, underwater light, area lighting, etc. type of loads. The absolute minimum sub panel size allowed to carry the load of just what you listed above would by the 55 amps you listed plus 125% increase due to continuous loads as per Article 680 that can be considered. That would put you to about 66 amps thus requiring a 75 amp panel serving that pool. This would put you close enought to a 100 amp sub panel that I would strongly consider increasing you sub panel size to 100 amp. If you have more load than you listed including some I listed that you may have overlooked you may want to go larger than the 100 amp. If I were you I would look a little closer and make sure you have enough panel size to do the job and cover any future wiring loads.

You said;
60amp GFCI breaker at main panel

Reply;
GFI protection must be installed for each specific branch circuit load installed. A feeder style GFI on the panel will not meet the NEC minimums.

~30ft #6/3 in PVC buried 18"

The 18" is fine. I challenge the # 6 sized feeder being big enough to meet NEC minimums as a feeder, depending on you final panel size that would change also to a larger conductor size required for that feeder. You wrote "6/3", this would not be proper wiring design. 680-25-D requires that your feeder must contain two ungrounded conductors, one neutral conductor, and one equipment grounding conductor that is insulated.

Now the NEC does require the wiring design as mentioned above being a 4 wire feeder as per 680-25-D. However the 99 NEC inserted the wiring styles found in 250-32. This would allow a feeder that is only two hots and a neutral and then installing a grounding electrode at that pool panel in that second structure, without adding that equipment grounding conductor as per 250-32-B-2. Yet if you install that feeder with that equipment grounding conductor installed with that feeder as per 250-32-B-1, you must use an insulated equipment grounding conductor. You are not allowed to install an equipment grounding conductor with that feeder to that pool panel unless it is an insulated equipment grounding conductor and not bare.

You said;
pool/spa subpanel box (sepatate neutral/ground bars)

Reply;
If you run a feeder between the main service rated panel and the pool panel without an equipment grounding conductor installed with the feeder, then you must install a grounding electrode at that pool panel and wired as per 250-32-B-2, then you must join the neutral bar and the equipment grounding bar in that pool panel.
If you run a feeder between the main service rated panel and the pool panel with an equipment grounding conductor installed with the feeder, you must separate that neutral bar and that equipment grounding bar in that pool panel.

It is the opinion of most that you must again install that grounding electrode at that pool panel disregarding the existence of that equipment grounding conductor, and I am unable to argue that belief of requiring that grounding electrode to be installed at that pool panel in this wiring style also, as per 250-32-B-1.

Again if with an equipment grounding conductor run with the feeder then separate that neutral and grounding bar in that pool panel. If without an equipment grounding conductor run with the feeder then join together the neutral bar and the grounding bar.

You said;
40amp breaker #8/3 to Heat pump in flexible conduit

Reply;
Yes # 8 guage is minimum size allowed to that heat pump,but you must run two hots, and a grounding conductor.

You said;
20amp breaker #12/3 to protected outlet for filter pump

Reply;
This filter pump must be with an insulated equipment grounding conductor and this branch circuit must be contained in a conduit from the panel if this pool is installed outside. This conduit can not be an EMT conduit if this pool is installed outside. This pool pump circuit must be dedicated and GFI protected. If you have a disconnect within sight of that pool pump and at least 10' away then you may hard wire that pool pump without a receptacle and without GFI protection and be next to the pool itself.

If you install a receptacle to serve as a form of disconnect for that pool pump, then you must again have install that 12 ga minimum sized insulated equipment grounding conductor and the branch circuit must be in a conduit. However your receptacle must be a minimum of 5' away from that pool's waters edge and must be with a UL approved weather proof cover and with a UL approved weathershield. If this receptacle is between 5' and 10' from the water's edge then that receptacle must be a twist lock style receptacle and plug. If this receptacle is beyond 10' then it may be a normal GFI receptacle or normal receptacle that is GFI protected. All receptacles serving a pool pump must be GFI protected if 15 or 20 amp rated and 120 volt rated. If the receptcle is 220 volt rated then no GFI is required.

You said;
grounding bar & #18 to bond filter/heat pump

You must install a bonding grid system serving any inground pool. This bonding grid has nothing to do with the electrical systems equipment grounding system other than a few incidental contacts. The source of the bonding grid serving an in ground pool is the metal sides of the pool or the rebar supporting a pool with non metallic pool sides. The intent is to connect any piece of metal that is 4" square or larger together to make all metals including the pool heater, pool pump, diving boards, metal ladders, underwater pool lights, etc. to be the same as one entity in contact with each other. The minimum wire size used for this bonding grid is a #8 copper wire. This bonding grid is not intended to be connected to the electrical system at all other than by incidental contact. Do not install a conductor connecting this bonding grid system to the electrical panel or to a grounding electrode such as a ground rod.

The subpanel will be in close proximity to the heat pump to double as a disconnect.

The breakers in that subpanel if in sight being not more than 50' and you can see it from the equipment may be used as a disconnect form for any equipment associated with that pool.

Be aware that special wiring methods exist to be required for and lighting associated to that pool also, yet you did not mention lighting.

You said;
Will this plan work? Is the one GFCI breaker at the main panel good enought to protect everything at the subpanel? What type of wire should I use(UF,THWN)?

Your plan has a lot of Code violations as mentioned above. No a GFI breaker at the main panel is not good enough to protect any piece of equipment associated with that pool. THWN if the normal type insulation used for pool associated wiring.

Hope this helps

Wg
 
  #3  
Old 06-14-01, 05:58 PM
Visiting Guest
Posts: n/a
Thanks for the prompt reply!

This is an above ground pool with no lighting right now, maybe I'll tackle that in the future.

How do these changes sound?

100 amp breaker at main panel(200 amp main panel)
30ft 3 wire(2 hots/1 neutral) #4 THWN in PVC (310-15-B-6) buried 18"
outdoor spa/pool subpanel (neutral/ground joined) with grounding electrode
50 amp GFCI breaker #8/3(2 hots/1 ground)(310-16) to heat pump in flexible PVC conduit
20 amp breaker #12/3 in PVC to GFCI outlet in covered weather proof box >10ft from pool wall for filter pump
#8 grounding grid for pool, filter, heat pump

If there's no neutral connection with the heat pump (2 hots/1 ground) how does it connect with the GFCI breaker?
Do I just connect the 2 hots to the breaker and the ground to the grounding bar then connect the GFCI neutral (pig tail) to the neutral bar? If this is the case will it still work if the neutral and grounding bars are connected? I thought the GFCI measured the difference across the hot and neutral wires? How does it do this with no neutral connection with the heat pump?
Also how do connect the pool wall to the bonding grid?

thanks again
 
  #4  
Old 06-14-01, 08:06 PM
Wgoodrich
Visiting Guest
Posts: n/a
You said;
This is an above ground pool with no lighting right now, maybe I'll tackle that in the future.

Reply;
You said above ground pool, all the reply I first entered would apply with a few adjustments such as the bonding grid being much less complicated.

You said;
How do these changes sound?

100 amp breaker at main panel(200 amp main panel)
30ft 3 wire(2 hots/1 neutral) #4 THWN in PVC (310-15-B-6) buried 18"

Reply;
I would say you are correct. However there are some that reply in this forum that says that 310-15-B-6 can not be used and your # 4 copper would have to be # 2 copper as per table 310-16. You should talk to your inspector to confirm his ruling on this feeder sizing.

You continued to say;
outdoor spa/pool subpanel (neutral/ground joined) with grounding electrode
50 amp GFCI breaker #8/3(2 hots/1 ground)(310-16) to heat pump in flexible PVC conduit

Reply;
The heat pump is not requried to be GFI protected, but may be anyway if you so desire.

20 amp breaker #12/3 in PVC to GFCI outlet in covered weather proof box >10ft from pool wall for filter pump

Reply;
We may have a problem here. First make sure you have green insulated wire for an equipment grounding conductor, White for a neutral conductor, then any other color for any hot conductors.

Then the NEC limits that cord on that pool pump to be a maximum of 3' and must be with a 12 ga. insulated equipment grounding conductor.

Also do not forget the requirement of the weather shields on any weather proof receptacle that is left plugged in unattended. A weather proof receptacle cover does not fulfill the weather shield requirement.

You said;
#8 grounding grid for pool, filter, heat pump
Reply;
The pool filter does not have any metals 4" sqare or larger. Look on the casing of the motor,if it has a lug on the outside of that motor casing then you are required to connect the pool shell if metal, the motor casing and the heat pump casing together to make the bonding grid.

You said;
If there's no neutral connection with the heat pump (2 hots/1 ground) how does it connect with the GFCI breaker?
Do I just connect the 2 hots to the breaker and the ground to the grounding bar then connect the GFCI neutral (pig tail) to the neutral bar? If this is the case will it still work if the neutral and grounding bars are connected? I thought the GFCI measured the difference across the hot and neutral wires? How does it do this with no neutral connection with the heat pump?

A 220 volt GFI breaker will measure a leakage to either the neutral or grouning conductor. If you have no neutral use then the GFI will be monitoring the two hots for overcurrent [too many amps] of the rating of the breaker, and also measure and react to any leakage of voltage to the equipment grounding conductor. The neutral pigtail coming from the GFI 240 volt breaker in this case would be connected to the neutral bar of the panel.

You said;
Also how do connect the pool wall to the bonding grid?

Reply;
Remove one of the nuts joining the pool shell together, scratch of any paint or other non conductive finish and install a grounding lug to that bolt and tighten down the nut. This #8 may be direct buried without concern.

One more thing I might mention. No sub panel is required to serve this pool or associated equipment. The equipment may be fed by individual branch circuits feeding each piece of equipment from the main panel in you home. You would have to use plugs and receptacles, a switch that disconnects all hot conductors feeding that piece of equipment, non fused disconnects or other approved forms of disconnect as required by the NEC. This wiring pattern using Branch circuits from the main panel may be less expensive and still do the same results including any hot tub you may add later. Just free info.


Hope this helps.

Wg
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes