pump killing relays

satpoolguy

Active member
Sep 16, 2014
26
San Antonio, TX
Last weekend, I returned home from a trip and found my pump circuit breaker tripped and the relay not working (doesn't switch, test button stuck in the down position). I ordered a new one and in the interim moved a relay of the same model from another circuit. Everything seemed to be working fine. Now, after having been away for a week, the exact same thing has happened, so it seems something is killing my relay. Pump is a Pentair Whisperflo. My understanding is that this model does not have a centrifugal switch. Any ideas?
 

JamesW

TFP Expert
Mar 2, 2011
14,973
Open the old relay to see what the contacts look like. Also, check the volts and amps with the pump on.

What are the pump label specs for H.P (horsepower), S.F (service factor) and amps?

Is the pump getting hot or loud?
 

satpoolguy

Active member
Sep 16, 2014
26
San Antonio, TX
Open the old relay to see what the contacts look like. Also, check the volts and amps with the pump on.

What are the pump label specs for H.P (horsepower), S.F (service factor) and amps?

Is the pump getting hot or loud?
Contacts appear to be melted together. I am about to go check the volts and amps. The pump is Pentair model 196234, I believe it is 1.5HP but neither that nor the SF is listed on the label. Amperage is indicated as 9.6-8.8. It doesn't seem to be noisy or hot.
 

gwegan

TFP Expert
Apr 19, 2013
2,769
Sacramento, CA
Just so I am clear you are saying that the pump relay switch is melted and the circuit breaker for the circuit which is a GFCI breaker with a test button has tripped with the button stuck down correct? And this has happened twice when you left it alone for a week so you don't know when in that week it occurred?

Is all that correct?

When you replace the relay everything operates fine? How is the relay wired to the motor? Any junctions splices? Have you inspected the connections to the motor? How do they look?
 

satpoolguy

Active member
Sep 16, 2014
26
San Antonio, TX
Just so I am clear you are saying that the pump relay switch is melted and the circuit breaker for the circuit which is a GFCI breaker with a test button has tripped with the button stuck down correct? And this has happened twice when you left it alone for a week so you don't know when in that week it occurred?
Right idea, but let me clarify some details. The contacts in the first relay I had the issue with appear to be melted together. I haven't removed the second relay yet but I strongly suspect I will find the same thing. I say that because my relays have a little test button sticking out of the bottom, which is connected to the plate with the contacts that moves inside the relay. On both the original and replacement relay, that test button is stuck in the up position...on the relay I removed, that's because the contacts are melted together, and I presume it is the same reason that the test button on the second relay is stuck, too. The pump is on a pair of regular circuit breakers, and there is no GFCI involved there. The test button I referred to in my original post is the test button on the relay itself. It is correct that this happened twice during a week when I was gone, so I don't know when it happened. When I installed the second relay, it turned on and off correctly several times, and then ran for a couple of hours and was still able to turn off.
When you replace the relay everything operates fine? How is the relay wired to the motor? Any junctions splices? Have you inspected the connections to the motor? How do they look?
Yes, it worked fine, at least for a while. The relay has 3 lines (2 + ground) that run through conduit from the relay to the pump. There are no splices or anything. The connections on the pump look fine, just like when I replaced the pump.
 

JamesW

TFP Expert
Mar 2, 2011
14,973
9.6 - 8.8 amps is a 208 or 230 volt motor. Are you measuring line to line or line to ground? What color are the power wires?
 

satpoolguy

Active member
Sep 16, 2014
26
San Antonio, TX
9.6 - 8.8 amps is a 208 or 230 volt motor. Are you measuring line to line or line to ground? What color are the power wires?
Yeah, my bad...that was a line to ground measurement. Line to line is 245.6 volts. (probably OBE now, but wires are 2 black and 1 green). Is 245V within range?
 

JamesW

TFP Expert
Mar 2, 2011
14,973
245 volts is ok. I suspect that the contacts are arcing due to high amps at startup. Does the pump seem to start ok?

Does the shaft turn easily?
 

satpoolguy

Active member
Sep 16, 2014
26
San Antonio, TX
245 volts is ok. I suspect that the contacts are arcing due to high amps at startup. Does the pump seem to start ok?

Does the shaft turn easily?
It does seem to start just fine, and i think the shaft turns easily. I've also checked the temperature with an IR thermometer, hottest spot is ~85F, which I'd imagine is fine. (ambient temp is ~65F)
 

JamesW

TFP Expert
Mar 2, 2011
14,973
Not sure what else to check. Maybe a transient power issue. Have you had power quality issues recently? Maybe power outages, brownouts, surges or spikes? Any other equipment having problems?

Do you have anything that could cause power quality issues like big equipment or anything that would pull power in a non linear way?

Possibly a surge protector would help.

Maybe a power quality monitor would provide some insight?
 

satpoolguy

Active member
Sep 16, 2014
26
San Antonio, TX
Not sure what else to check. Maybe a transient power issue. Have you had power quality issues recently? Maybe power outages, brownouts, surges or spikes? Any other equipment having problems?

Do you have anything that could cause power quality issues like big equipment or anything that would pull power in a non linear way?

Possibly a surge protector would help.

Maybe a power quality monitor would provide some insight?
I haven't had any issues with other equipment, pool related or otherwise. The electric company did replace my electric meter a few weeks ago. I suppose that could be related, but it seems unlikely. No big equipment, and nothing at all changed in the environment for many months, other than the new meter. The equipment box already has a surge protector, which isn't blown.

- - - Updated - - -

Have you manually turned the shaft?
Yes, and it feels fine to me (to the extent that I even know what "fine" is)
 

Charlie_R

TFP Expert
May 8, 2013
2,156
Mexico, MO
Have there been any changes in your neighborhood, like a new shop opening that would use heavy electrical draw for short periods of time?

I ask, because I've had essentially the same thing happen when a local shop "upgraded" their equipment to higher hp motors. My neighbors also experienced issues from this, until the electric company stepped in and made a few changes to the high lines feeding our area.
 

satpoolguy

Active member
Sep 16, 2014
26
San Antonio, TX
Have there been any changes in your neighborhood, like a new shop opening that would use heavy electrical draw for short periods of time?

I ask, because I've had essentially the same thing happen when a local shop "upgraded" their equipment to higher hp motors. My neighbors also experienced issues from this, until the electric company stepped in and made a few changes to the high lines feeding our area.
Nothing that I can identify. I live in a very residential neighborhood, but I suppose anything is possible.

- - - Updated - - -

fwiw, I ran the pump about 15 hours straight with no problems, and then it shut off fine. I turned it back on a few minutes later, and I'm hoping for the best, but I'm not tremendously optimistic, given that 2 relay failures in about a week is very unlikely to have been a coincidence.
 

Charlie_R

TFP Expert
May 8, 2013
2,156
Mexico, MO
How close is your neighborhood to the nearest industrial/commercial area?

If your electric utility feeds are above ground, see if you can follow the wires back to your neighborhood's substation. If there is a feed on the same set of wires going to an industrial area, talk to your power company about putting a recorder on your meter for a week, and see how much the incoming power fluctuates.
 

JohnT

Admin
Mod Squad
TFP Expert
Apr 4, 2007
9,536
SW Indiana
A guess would be that your input voltage is dropping during startup or at other times and that causes excess current draw. What happens is that as the relay engages or disengages it arcs and welds a bit of the contacts together. When it's bad, they stick together and you are done.

First thing would be to check connections everywhere.

Anything new in the house like a heat pump etc. or construction nearby?

Maybe measure the pump input voltage while the pump is starting looking for drops.
 

satpoolguy

Active member
Sep 16, 2014
26
San Antonio, TX
I have traced everything back to the main panel as best as I can without removing wires from the tubing. All appears well. Nothing new in the house, and no known construction nearby. I'm not even sure where the nearest industrial area is...at least 10 miles away, I'd say. Relay is rates at 25A.

The good news is that the latest relay survived all week. I'm cautiously optimistic that there was a short lived anomaly that killed the 2 relays in quick succession, and that now I'm all set. I'll post again after I see if it survives another week.