4 Months and Three Pump Replacements/Ladder Corrosion !! ..

gotee

Member
Jun 21, 2010
18
mechanicsville virginia
We had a new pool installed and was finished the first of April. We decided to go with a SWG installation because of the supposed 'ease' of upkeep on these pools. I've owned pools in the past and they were exclusively regular chlorine pools. This one has been a nightmare so far. Since April the pool contractor has replaced three Pentair Whisperflow 1.5 hp 2-speed pumps because of seal/bearing/impeller screw corrosion. The first indication we had of corrosion was rusing of the bolts on our stainless steel ladder. The water was initially set up by the contractor recommended retail outlet nearby and i've taken it to them for adjustments every two weeks since. At first the chlorine levels were quite high during the first three weeks, but after adjustments parameters are to quote the retail outlet, 'perfect'. For some reason, they had me add stabilizer 4 times at first, but now the levels are @ 56. Chlorine varying between 3-4, ph, alkalinity and dissolved solids within norms. Salinity is @ 3400ppm as recommended by Pool Pilot (Digital with SC-36 cell running as two speed). Pool capacity is 25,000 gal. We had the pool bonded beyond life so to speak. everything was triple bonded, pump, pool pilot head unit, auto fill, ladder, aluminum coping, outlets, aluminum fencing, 'park' type light post, 600 watt low voltage transformer for lighting around pool... everything. They replaced one pump this past Sunday, and by wednesday the seal had started leaking. They took the pump apart and the screw had already deteriorated to the point of needing to be replaced and the seal/bearing/spring was covered in rust! What the heck is going on here?!..
 

Melt In The Sun

TFP Expert
LifeTime Supporter
Oct 29, 2009
3,899
Tucson, AZ
Welcome to TFP!

What you are experiencing is very unusual. It would help if you could post a full set of test results (FC, CC, pH, TA, CH, CYA, Salt). I've never heard of pump seals failing so quickly; perhaps the contractors are doing it incorrectly?

Hopefully some more folks will be along soon to comment.
 

JohnT

Admin
Mod Squad
TFP Expert
Apr 4, 2007
9,476
SW Indiana
For it to rust that fast, I'd be thinking an electrical problem. I believe I would start by checking everything electrical involved with the pool for a hot/neutral reversal or even a missing or loose neutral. Then check your service panel for neutral issues. It sounds like current is flowing from the water into the bonding system.

Are you in a rural area or close to other houses?

It may be that your bonding system is doing exactly what it is supposed to do, but is masking a serious electrical issue. I would suggest an electrician.
 

gotee

Member
Jun 21, 2010
18
mechanicsville virginia
The replacement pump Sunday was straight out of the box. The contractor just bolted it in and plumbed it. No seal tampering on his part, then it started leaking Wednesday requiring a replacement. I am at work at the moment and cannot post a complete set of parameters, but according to the retail outlet recommended by the pool contractor, they are almost 'perfect' every time.
 

dmanb2b

TFP Expert
LifeTime Supporter
Apr 4, 2009
3,734
NY
yup...saltwater pools have been around for 40+ years...your issue is not being caused by 3-4Kppm of salt.
 

gotee

Member
Jun 21, 2010
18
mechanicsville virginia
Interesting that you mention an electrical issue. Another contractor that was at the retail outlet when I went in mentioned that when I was talking to the owner of the store about my issue. I wonder if my low voltage lighting is causing this? We have a 600 watt transformer connected to 34 low voltage lights that the wiring connectors are buried in mulch with irrigation keeping them moist at all times. Could the leakage around the connectors cause this?
 

JohnT

Admin
Mod Squad
TFP Expert
Apr 4, 2007
9,476
SW Indiana
gotee said:
Interesting that you mention an electrical issue. Another contractor that was at the retail outlet when I went in mentioned that when I was talking to the owner of the store about my issue. I wonder if my low voltage lighting is causing this? We have a 600 watt transformer connected to 34 low voltage lights that the wiring connectors are buried in mulch with irrigation keeping them moist at all times. Could the leakage around the connectors cause this?
I doubt the LV lighting has the current to do something like this so quickly, but I don't know for sure. I'd just about bet you have 220V or 110V running through your water to/from the pump shaft.
 

JohnT

Admin
Mod Squad
TFP Expert
Apr 4, 2007
9,476
SW Indiana
I'd probably try shutting off power to the equipment, pulling the bond wire from the pump and clip your meter leads to the bond wire and ground and turn the equipment back on. Treat the bond wire and case of the pump as hot while they are seperated and make sure nobody is around the pool.
 

GCS

Well-known member
Jul 28, 2008
161
Wish I could help here but I am no electrical expert (done a lot of wiring but not troubleshooting) but it's nice to see another mechanicsville resident on here. Hey neighbor :handwave:

Greg
 

gotee

Member
Jun 21, 2010
18
mechanicsville virginia
Good to see a neigbor on here! Howaya Greg? Just spoke with the electrician.. he'll be out first thing tomorrow morning.. Per his instructions called and had the electrical shut off to the pump house...why do i suddenly feel sick to the stomach after hosting a party with over 80 people in attendance?!..
 

NCFlyersFan

LifeTime Supporter
May 30, 2008
116
NE North Carolina
Do you have a pool light? What is the voltage? (Pardon the next question, AGP owner here) Is there enough cable on the light to remove it and get it above the surface onto your deck???

Sounds like a classic case of galvanic corrosion, which is accelerated in the presence of an electrical voltage.
 

GCS

Well-known member
Jul 28, 2008
161
I'm good man I just hope you get this issue sorted out as this does not sound good.

Keep us posted on what you find out though as this could be good reference material for someone else in the future who has something odd like this come up.

80 people -- now that is a party!!

Greg
 

gotee

Member
Jun 21, 2010
18
mechanicsville virginia
OK.. a little testing last night on my own.. electrician coming some time today. All water parameters good PH @ 7.1.. chlorine @ 2.1.. etc..We turned all power off, then disconnected the pump bonding wires. After putting on rubber boots and gloves (ha) I connected the test leads to the pump bonding lug (case) and bonding wires to grid (also to ground wire seperately after performing tests on bonding wires but with same results-albeit with very slight numbers). Had helper turn on pump-no voltage flowing from pump through to bond OR ground. Further had helper turn on each circuit in the panel in the pump house to check for jumps/spikes-nothing. Then forced the auto-fill to turn on-nothing. Then manually changed the pump speed from full 1.5 hp to low speed-nothing. I even forced the SWG up to 100%-nothing! Argggggh !! .. After pulling what's left of my hair out, i decided to further isolate the pool by removing the stainless stell ladder that extends into the water. I put the pos lead of my milli-amp/volt tester in the water then grounded it to the stainless handrail that is bonded and doesn't extend into the water-8.89mv gradually discharging through the tester to ground.. hmmm... put stainless ladder back into the pool-thus grounding the water directly.. reading changed to 4.1mv discharging gradually through tester. These are MILLIVOLT readings.. nothing very significant to speak of. Then I turned on the low voltage lighting around the pool.. all 34 of 'em.. the reading shot up to 8.9 and held.. gradually.. VERY gradually climbing .01mv ever two seconds or so.. keeping in mind that the ladder was removed and the bonding lug was disconnected at the pump. I guess my intuition is that the bonding is doing what it's supposed to, with very slight current being generated by the pool with some bleed through from the low voltage lighting, but nothing significant enough to cause this corrosion at the screw.. UNLESS !!!.. hypothesis here.. the bonding should be connected to the main ground for the panel?? it isn't.. and since it isn't it's finding the BEST ground which is through the wiring to the pump, thus attacking the only contact to the water via metal.. THE SCREW !! am I right in assuming this electrically inclined people? Should the electrician have connected the bonding to the main ground to the panel?! .. This is an extremely easy fix if this is the case.. and should i even add a couple ground rods and connect them back at the pool (i had the electrician run extral bond wires to the aluminum fencing and it would be easy to connect them there)?
 

Bama Rambler

Mod Squad
TFP Expert
LifeTime Supporter
Jun 22, 2009
23,062
SouthWest Alabama
The pump should be grounded (not bonding) to the panel through the power cord. The bonding doesn't get connected to the panel ground in the U.S. It's two separate entities.
 

JohnT

Admin
Mod Squad
TFP Expert
Apr 4, 2007
9,476
SW Indiana
No, the bonding wire isn't supposed to be connected to the ground (in the US). It's already connected to ground through the case of the pump.

You shouldn't measure anything between the rail and the water since the water should be connected to the bond system by some means anyway.

Are you in an area with wells, any nearby neighboring homes or businesses?