Swimming Pool Wiring Questions [Archive]

Wgoodrich

October 23rd, 2002, 03:05 PM

You said;
I recently installed a steel wall in-ground swimming pool and have a few electrical questions. The pool has in addition to the filter, a 110 volt light, 24 volt dc fiber optic light around the pool and a 220volt heat pump and a polaris booster pump.

REPLY;

We are going to need a bit more details on some of your equipment before I can answer accurately. YOu discriptions are a bit confusing to me.

You are saying that you have a 120 volt light [is this a 120 volt underwater light that you are talking about here?] {If this is an underwater 120 volt light is this a wet niche or dry niche type underwater light, this is the mounting dish the light kit mounts into, is this niche in the wall of the pool flooded with water or sealed from water inside the niche?}

You then mention low voltage lights with a transformer but mention fiber optic lighting. Most fiber optic lights that I have seen are the strings to the areas of lighting coming from one metal box with a 120 volt high output power spot light bulb that emits light into the fiber strings that carry the light through the strings with no electric at the light output at all. Is this what you have? Are you talking about this fiber optic lighting and the low voltage all as one lighting kit or are you talking about two different type of lighting kits? Are these fiber optic lights area lighting or underwater lighting? Are the low voltage lights area lighting or underwater lighting?

I need clarification of the above before we can talk the rule of the NEC that would apply. Each lighting style mentioned have their own set of NEC rules that dictate how they must be wired. Once I know exactly what you have then I can tell you the rules of the NEC that apply to that lighting design.

YOU SAID;
My questions are: 1) Can the 110volt line for the light also be used for the 24 volt dc fiber optics (I assume there is a converter) and can I have them on separate switches?

REPLY;
We need to know if this underwater light and this 24 volt fiber optic lighting are both underwater lighting or one is underwater lighting and the other is area lighting for the patio area. I would like to see you confirm this [24 volt and fiber optics combination] I am suspecting there is a confusion in this statement. I am suspecting you plan ot use low bagota style 24 volt area lights around the patio of the pool. Is this correct? Just guessing at this point from what you are discribing.

YOU SAID;
2.) What gage wire do I need to use for the 110V and for the Heat Pump?

REPLY;
I am taking your 120 volt to mean your lighting circuits and the heat pump being a third circuit. If I am right please confirm. Also in order to answer this I need clarification as to what you are doing. You speak of heat pump yet heat pump systems rarely are used to heat the water of the pool. Is this pool installed inside a building or outside in the weather? Is this heat pump being used as a desert air system heating a room or as a pool heater directly heating the water? I believe I am missing something concerning this heat pump concern. Also look on your heat pump name plate and look for MAXIMUM OVERCURRENT I need this to answer you maximum breaker size allowed for this unit. Also look on that same name plate of the heat pump for MINIMUM BRANCH CIRCUIT AMPACITY this will tell us the minimum conductor size required to serve this heat pump unit. Also we need an air handler for this heat pump. If this is a desert air system used on an inside pool installation inside a building then the air handler most often is all one unit with the heat pump. If this is a normal heat pump for area heating of a room then you will have a separte heat pump and a separate air handler. If this is the case then I need the voltage and amp rating or KW rating of that air handler on the name plate also.

If this is a heat pump designed to directly heat the pool I have some questions as to the use and design. Heat pumps at best produce temperatures of about 80 degrees if without eletric assist heating. This leads me to believe you either have a heat pump being used in an unorthodox manner or you must have more load than just the heat pump. If this is the case look for heat banks in your air handler and we need that load rating on both the heat pump and air handler including the heat banks installed in the air handler assist heat.

YOU SAID;
3.) Can the outlet required by code run off the line for the filter pump and can this line power the Polaris Pump?

REPLY;
No, the filter pump will pull more than 50% of the ampacity of the branch circuit serving that motor. The NEC forbids utilization equipment that pulls 50% or more of the amp rating of a circuit to carry other loads [receptacle]. Now if you are installing this pool outside and if you have an outside receptacle on your home GFI protected and it is within 20' of that pool then that outside house receptacle may serve as you general use pool receptacle required.

YOU SAID;
4.) Can all of the wires including the heat pump be in the same conduit?

REPLY;
Any branch circuit that is GFI protected is only allowed to share a conduit with other branch circuits if those other branch circuits are also GFI protected. I advise that you do not install a GFI protective device on that hermetic motor in that heat pump. A hermetic motor windings is bathed inside that motor with liquid. GFIs are not known to be to compatible with hermetic motors due to the GFI picking up what it would consider current leakage inside that hermetic motor. The GFI won't hold on the hermetic motor [compressor motor] due to the emerssed wiring designs of hermtic motors.

Your heat pump and your area lighting is not required to be GFI protected nor is your pool pump motor if without a receptacle. If you ran two conduits you could install all GFI protected circuits in one conduit and all non GFI protected circuits in the second conduit. BE careful with running more than three current carrying conductors in the same raceway no matter how oversized the conduit. Table 310.15.B.2.A requires you to start derating ampacity of these conductors the more current carrying conductors you install in the same raceway. Most commonly you can run approximately 8 or 9 current carrying conductors in a raceway without ampacity deration concern due to that table. Just wanted you to be aware of this rule.

YOU SAID;
I understand about the 8 Ga ground wire around the pool but how many places does it have to connect to the walls of the pool and are there special fitting to do this?

REPLY;
In the way you speak in the above question I suspect you don't understand the purpose or required design of a bonding grid system concerning a pool. The metal sides of your pool is the source of your bonding grid system. You are not bonding the metal side to ground you are bonding all metal parts 4" square or large associrated and within 5' of that pool plus all pool associated equipment such as pool motors, heater, ect. to that metal side of the pool. YOu source of the bonding grid is the metal sides of that pool. The purpose of the bonding grid system is to make all metals 4" square or larger within 5' of the pool and all pool associated equipment to be one entity eliminating the difference of potential that creates a shock hazard. If all metals are of equal value with each other there is no place that you can be shocked. This bonding grid system is contained within the pool installation and is not intended to be connected to any grounding electrodes [ground rods] and is not intended to be intentionally connected to the equipment grounding system of your home electrical system. The entire purpose if to make a metals associated to that pool one entity [potential] with the metal side of your pool.

It is not intended that you install a 8 awg copper wire around your metal pool sides. All that is intended is that you connect metal parts to the metal side of the pool as the source of this bonding grid system.

For example a metal handrail will have brackets that are set in the concrete where the hand rail then slips into these embedded metal brackets to support those metal hand rails. On those metal brackets that are embedded in the concrete you will find lugs to connect your 8 awg copper bonding grid wire. Then the other end of that 8 awg copper bonding grid wire is simply connected by a bolt on lug that is bolted on one of the bolts and nuts of the metal pool sides connecting those metal side pieces together. The bolt on one hole lug must be approved for direct burial in concrete. Most lugs are just check the listing and labeling that come with those bolt on lugs. All you have then is a short piece of 8 awg copper wire connected from that lug on the handrail bracket ran and connected to the nearest point of the metal sides of that pool, that is it for that piece metal hand rail to be bonded to the bonding grid.

No other grounding or connecting to earth is intended. The metal pool side is the source of your bonding grid system.

Try reading the following link that may help, it is an article on our Homewiringandmore web site that is based on the 99 NEC. Sorry I don't have the 2002 NEC version of that article written yet. However within the next week or so there will be a new 2002 article posted on our homewiringandmore web site for above ground pools. Takes a lot of time writing these articles then posting them on the web site. Please be patient and I will get the 2002 NEC articles all done as soon as possible. Then we hope next year to write articles concerning the Canadian electrical code. Try the following link and see if it helps some and get us the info on the questions we asked in this reply then we can get down to more explicit answers that can be more accurate to what you are doing.

http://www.homewiringandmore.com/homewiringusa/2002/accessory/poolperm/poolperm.html

I am including a picture of the new inground pool article that may help you see what I am trying to explain concerning pool bonding grid systems. Hope this helps

Wg

http://www.homewiringandmore.com/storage/ingroundpools/ladderbracketbonding.jpg

http://www.homewiringandmore.com/storage/ingroundpools/handrail2.jpg