GFCI protection on swimming pool pumping equipment

[rlqdot]

I am designing the electrical system for a swimming school. the building has several "current pools" - those tanks that we all see advertised here and there that have flow motors in one end of the pool. those flow motors are driven by a hydraulic pump located in a remote pool equipment room.

I know the NEC is very emphatic about GFCI protection for equipment that contacts the pool water, in addition to specific grounding and bonding requirements to maintain equipotential grounding plane. on my drawings, I called for a GFCI breaker to protect the hydraulic pump - my reasoning was that any fault in the pump motor (it is an immersed pump / motor - like a hydraulic elevator) could lead to energizing the hydraulic fluid in which it is immersed, which could energize the flow motor, which could energize the pool water in which it is immersed.

now in construction, the contractor has informed me that he cannot find a source for the 60 amp - 3 pole - 208 volt GFCI circuit breaker I called for.

So, my question is - am I required by code to provide GFCI protection to the hydraulic pump? I know it is not the pool WATER circulation pump, but in a round about fashion, i see the possibility that it could energize the pool water just as easily as a faulted water pump motor.

Thanks for any feedback

 

[texie]

I am designing the electrical system for a swimming school. the building has several "current pools" - those tanks that we all see advertised here and there that have flow motors in one end of the pool. those flow motors are driven by a hydraulic pump located in a remote pool equipment room.

I know the NEC is very emphatic about GFCI protection for equipment that contacts the pool water, in addition to specific grounding and bonding requirements to maintain equipotential grounding plane. on my drawings, I called for a GFCI breaker to protect the hydraulic pump - my reasoning was that any fault in the pump motor (it is an immersed pump / motor - like a hydraulic elevator) could lead to energizing the hydraulic fluid in which it is immersed, which could energize the flow motor, which could energize the pool water in which it is immersed.

now in construction, the contractor has informed me that he cannot find a source for the 60 amp - 3 pole - 208 volt GFCI circuit breaker I called for.

So, my question is - am I required by code to provide GFCI protection to the hydraulic pump? I know it is not the pool WATER circulation pump, but in a round about fashion, i see the possibility that it could energize the pool water just as easily as a faulted water pump motor.

Thanks for any feedback

A 3 phase pool pump motor would not require GFCI anyway, so I think the fact that your motor is not in contact with pool water is moot.
Even if you had a single phase "pump" as you describe I'm not sure it would require GFCI as it is not circulating pool water.
All that said, if you want GFCI I guess one would have to go to somebody like Bender.

 

[Jraef]

So there is a hydraulic fluid pump that is driving a water pump? Terribly inefficient, but I can imagine they do it BECAUSE if the hydraulic pump motor insulation fails, it would NOT "energize the hydraulic fluid". Hydraulic fluid is oil, it's not conductive.

 

[GeorgeB]

So there is a hydraulic fluid pump

you mean hydraulic fluid motor

that is driving a water pump? Terribly inefficient, but I can imagine they do it BECAUSE if the hydraulic pump motor insulation fails, it would NOT "energize the hydraulic fluid". Hydraulic fluid is oil, it's not conductive.

Hydraulic fluid is not always oil. In many environmentally sensitive applications, it will be glycol, basically antifreeze, often propylene glycol mixed with water. I'm unsure of insulating qualities, but suspect it to be a pretty good conductor.

I agree with your feeling however, elimination of any underwater electrified components. Yeah, efficiency is poor vs an electric driven pump. There are significant advantages, but none I can think of that would apply here.

 

[mpoulton]

Most hydraulic lines are fully conductive, since they are reinforced with steel braid which contacts the crimped fittings at both ends. The only non-conductive high pressure hydraulic lines are the ones specifically designed to be insulating, like for bucket trucks. Considering this, the hydraulic pump assembly might as well be submerged right in the pool itself. If the hydraulic pump faults to ground and the fault isn't cleared, the water pump in the pool will be hot. GFCI or GFPE seems like a good idea even if it's not required by code.

 

[Mystic Pools]

Taking a guess, the hydraulic pump is for an automatic pool cover??

We installed this type only once for an outdoor pool. Normally we use the standard electric motor located in the trough for the cover itself. It's within 12" of the pool water and we do GFCI protect and bond that motor.

The hydraulic pump was located at the pool equipment with hydraulic hoses run to and from that same trough through a 3" conduit. This motor was in fact away from the pool. We did however still GFCI protect and bond as well.

Hydraulic pump is SLOW in the spring as the fluid is pretty cold.

 

[Mystic Pools]

Sorry read OP a bit too fast. Not an automatic cover. Perhaps the hydraulic pump I mentioned, and the way it was handled electrically, will be the same procedure for your project.

Just wondering if you could give more details on this hydraulic pump. Trying to figure out it's application/purpose. Manufacturers name.

I have not heard of any flow motors you mention driven by a hydraulic pump for swimming pools.

 

[rlqdot]

Hydraulic pump (located in equipment room) drives a motor immersed in pool. That motor is equipped with a propeller that creates a current the water so that the swimmer feels like he /she is swimming against the current in a stream. Pump is on a VFD so speed of motor, and therefor the watercurrent, can be varied.

 

[Mystic Pools]

Hmm. Not familiar with a set up like that.
I am familiar with a swim spa which essentially gives the same results but using different components.
Swim spas have a giant jet that is set in the center of a swim vessel, that is driven by a pool pump, spec'd in size for HP and water flow, that draws water from a suction inlet and in turn supplies water to the jet.

The pump can be a typical type with it's own impeller, lint basket, etc.. Provided it's sized properly and the pipe size is correct, you will achieve a constant jet that you "swim" into. The swimmer is tethered to prevent from being pushed back during swimming.

Badu Jet is a company making these jet types complete with a pump. I'm not sure if they have a VFD system in place for their products.

You can however use a variable speed pump or purchase a separate VFD for virtually any pool pump.

We used 3 VFD systems on a commercial pool about 8 years with great success. A true energy saver. We took the single phase coming into the building, and converted the power supply to the pumps to 3 phase, to operate 3 separate 3HP, 3 phase pool pumps.

Your application is different though to vary the flow for volume as opposed for energy saving purposes.

I am still very interested in the manufacturer of this product you are specifying and the design set up. I have never heard of such a system you describe utilizing a hydraulic pump to run an immersed motor.