burned out pressure switch

Discussion in 'Pumps and Tanks Well Forum & Blog' started by john c, Jul 20, 2014.

  1. john c

    john c New Member

    Messages:
    25
    Location:
    SC
    The pressure switch to a 10 year old 1 hp goulds jet pump wired for 240 (230) volts quit working and I could smell burnt plastic. I replaced the switch and the same thing happened within two days. I looked closer at both of the failed pressure switches and both have melted plastic where one of the wires #2 from the pump contacts at the switch, where 2 and 3 go to the pump and 1 and 4 are to the power supply. I have a multi meter but haven't checked anything yet. My only guess would be a capacitor. I've only used the pump for irrigation, washing the car, in the summer, so hoping it still has more life, and the pump still works. Any suggestions would be appreciated. Is this a common sign that the pump is going bad? Thanks!
  2. craigpump

    craigpump Well-Known Member

    Messages:
    1,038
    Location:
    ct
    A lot of the time a short cycling pump will do the same thing
  3. john c

    john c New Member

    Messages:
    25
    Location:
    SC
    It has a stop cycle valve and runs for over 20 minutes when in use for the irrigation. I tested it on the lower water flow applications and never heard any kind of problems with it, but wasn't there when it happened. Is there anything else you might suggest? I suppose I'll get another pressure switch today and start testing it out again. Any other suggestions would be greatly appreciated as I'd like to keep using the pump and not burn up the pressure switch.
  4. Reach4

    Reach4 Well-Known Member

    Messages:
    2,655
    Location:
    IL
    You can do a qualitative test of the capacitor of the capacitor by touching the isolated terminals with your ohmmeter. If the meter is analog, the needle should kick to low resistance initially, and then rise to high resistance. If you short out the capacitor terminals to discharge the capacitor, you can then repeat the test. If you reverse the test leads without discharging the capacitor from the last test, you would get an even-bigger kick.

    The amount of kick will vary with the capacitor and the ohmmeter. With a digital meter, you would get corresponding readings, but it would be trickier to get a meaningful test.

    How many starts would you estimate are on your capacitor. I am not implying that I know if a failing capacitor could cause your symptoms. But replacing the capacitor after 10 years may be a good idea, even if it was not needed.

    With about a 1/2 GPM flow from a hose, does the pump take about the amount of time that you expect for the pump to turn off? With a failed pressure tank, the pump would short-cycle.

    I am not a pro.
  5. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    4,149
    Location:
    NW Ontario, Canada
    It's the amps that burn up the contacts so measuring the amps drawn would be a good place to start. You can also measure the ohms resistance on the motor to see if it is in spec.
  6. john c

    john c New Member

    Messages:
    25
    Location:
    SC
    Appreciate the tips. This time I moved the pressure switch to the other side of the stop cycle valve closer to the tank. It is wired for 120 volts, not 240. It is drawing 119 volts and I couldn't figure out how to get a reading on the amps. I have a digital Greenlee. Also not sure how to get any other readings and would need more specific instructions. I did get a reading of 174 when touching the two copper plates under the cover. I'm hoping that just by moving it the switch it will help. The last time it was running at 2:30 pm and its very hot and humid so maybe just moving it away from the hot pump will help. Any other suggestions?

    It has a stop cycle valve but when there is just a trickle discharge or no discharge it builds pressure very fast as it draws about 18 GPM with a small tank.

    I hope it keeps working this time but burning up two switches isn't encouraging.
  7. Reach4

    Reach4 Well-Known Member

    Messages:
    2,655
    Location:
    IL
    The pressure switch needs to be at the pressure tank with no valve or anything in between except a fairly short pipe. Moving the pressure switch should help prevent short cycling. When you use water for the irrigation and then stop using water, how long does it take for the pump to turn off?

    Did you say the pump is wired for 120 VAC but you read 174 volts? You need to review your electrical connections. If the pump is wired for 120, you should never see 174 volts between anything inside of the pressure switch.
  8. john c

    john c New Member

    Messages:
    25
    Location:
    SC
    Thanks Reach4. It's all wired for 120 volts and the pump is at the right 120 setting. Short cycling hasn't been the problem. While I'm not handy with the mutimeter, I did notice the same two terminals on the switch were hot to the touch after running it 40 minutes but not enough to melt plastic and I could keep touching it, but probably not good that its hot again? I may try to find another capaciter and replace that. I'll do some research on how to use the multi meter. The pump is working fine.
  9. Reach4

    Reach4 Well-Known Member

    Messages:
    2,655
    Location:
    IL
    Normally when you control a 120 VAC pump through a pressure switch, you only use two of the terminals (one pole of the switch). You do not switch the neutral (white) wire. Maybe you can rewire this properly and can use the pole of the switch that has not failed.
  10. john c

    john c New Member

    Messages:
    25
    Location:
    SC
    It's wired properly. The power supply uses #1 and #4 and the two wires to the pump use #2 and #3. There is setting on the inside of the pump that is also set correctly to 120 volts. The pump appears to be drawing too man amps because the two pump terminals are getting hot. I don' think my multi meter can measure amps to AC, so I may get one that can. I'm not sure how hot the two pump terminals should get? I'll test it more tomorrow when its not raining. The stop cycle valve may be causing it to run hotter at low GPM, or it's the capaciter or something I'm not aware of. Thanks for the help! At this point I'm not going to pay to have a 10 year old pump repaired.
  11. john c

    john c New Member

    Messages:
    25
    Location:
    SC
    Ok, you are saying bypass the switch for the white wire, by connecting it straight to one of the motor wires? And the switch would the back and other motor wire? I'm on the third switch now, but the original switch and the way it's wired now worked fine for 10 years.
  12. valveman

    valveman Moderator Staff Member

    Messages:
    4,549
    Location:
    Lubbock, Texas
    The pressure switch always needed to be on the tank side of the CSV. You may have damaged your motor having the pressure switch on the wrong side for so long. With the pressure switch on the pump side of the CSV, the pump may stay running while the irrigation system is on, if the irrigation system uses all the water the pump can produce. But when you were using water in the house or just less than the pump can produce, the pressure switch on the wrong side of the CSV would cause rapid and numerous cycles. As Craigpump said, this is usually what melts down a pressure switch. Moving the Pressure switch to the tank side of the CSV should solve this problem.

    The motor has an internal thermal overload. If the motor were drawing too many amps the overload would shut off the motor. (Same thing if the capacitor is bad) These are auto-reset overloads, so it would have reset in a few minutes and restarted the pump, but you would have seen that happening.

    With the pressure switch located correctly, the CSV will keep the pump running as long as you are using more than 1 GPM. But this will not make the motor run hotter. To the contrary the restricted flow caused by the CSV will actually reduce the amperage of the motor, making it run cooler, not hotter.

    But the rapid cycling that occurred when the pressure switch was on the wrong side of the CSV would certainly cause heat and melt the pressure switch.

    Also a 1HP running on 115 volts is drawing the same amperage (pressure switch heat) as a 2HP pump running on 240 volts. This is the maximum amperage you can run in a FSG2 type pressure switch. It would only have half the amperage or heat on the pressure switch if you switched it to 240 volts. Nearly all jet pumps can be wired 115V or 240V. You would just need a double breaker in the panel for 240V instead of a single breaker as with 115V.
  13. john c

    john c New Member

    Messages:
    25
    Location:
    SC
    Thanks for chiming in Valveman. The pump isn't cycling on and off. It's only used for irrigation. Today I ran it for 40 minutes with the new pressure switch that I relocated, and the two terminals for the wires to the pump got hot again. The same two that melted with the other two pressure switches. Once again it ran continuously for 40 minutes, started one time and shut off one time. So I'm thinking it might be the capacitor. I'd like to simply replace it to see if that helps. After 10 years it can't hurt. The pump is working fine, it's just heating up the two terminals in the pressure switch. Where could I order a new capacitor for a 1 hp Goulds jet pump? Some of the lettering on the side was warn off from the heat, and I'll check it again tomorrow. But would this be it, a 9L114?

    The stop cycle valve has worked great. I'm not seeing a difference moving the pressure switch but wanted to rule that out so did it. It takes over 3 GPM for it to not cycle but that's fine because everything I use is over 3 GPM.

    I also don't have any more room in my control panel for another 240 so I'll need to use the 120 that has been working fine for 10 years. It's a 10 gage wire running a short distance.

    Appreciate the help.

    http://www.pumpagents.com/GouldsPumps/9L114.html
  14. Reach4

    Reach4 Well-Known Member

    Messages:
    2,655
    Location:
    IL
    What about switching the neutral? I am confident that is not necessary or advantageous.
    Last edited: Jul 20, 2014
  15. john c

    john c New Member

    Messages:
    25
    Location:
    SC
    Sorry for any confusion it's a 1 hp shallow well pump.. The model # is C48A95A06 .. that is printed on the pump.
    http://www.wwpp.com/products/goulds/jetpumps.htm

    That was the only capacitor that came up with a Google search and I didn't know if it was the right one. I can't seem to find the right part to order. I was going to call a local pluming supply place tomorrow but don't know how much help that would be.

    But yes its a two wire set up. On the inside of the pump, under the cover, it has instructions for wiring for 120 or 240. It's very straightforward and is properly wired for 120. It may have even shut off when it overheated.

    If I can find the right capacitor to order I'll just do that and switch it out.
  16. john c

    john c New Member

    Messages:
    25
    Location:
    SC
    Once again, appreciate all the help! I'll probably just start a new thread tomorrow and try to find the right capacitor to order. If that doesn't work, and keeps overheating, might be time for a new pump, and will start a new thread for that one. :)
  17. valveman

    valveman Moderator Staff Member

    Messages:
    4,549
    Location:
    Lubbock, Texas
    A starting capacitor is not going to help. The capacitor is only in the circuit for a fraction of a second on start up. As soon as the motor gets up to speed the centrifugal switch in the back of the motor opens up and takes the capacitor out of the circuit completely. If the pump is starting, the starting capacitor is good.

    If it is not cycling, maybe you have a loose wire connection somewhere. Although a 1HP on 115V is maxing out the amperage on a FSG2 pressure switch, so it will get warm.

    Another thing is those little plastic clips on the pressure switch points can't take heat like the old fiber board style that you can't get anymore.
  18. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    4,149
    Location:
    NW Ontario, Canada
    I agree with valveman. The starting cap has nothing to do with the contacts getting hot.

    What you could do is to wire both sets of contacts in parallel.
  19. valveman

    valveman Moderator Staff Member

    Messages:
    4,549
    Location:
    Lubbock, Texas
    Now that's a good idea. Don't run the common through the pressure switch and split the other wire between both sets of points. That would cut the amperage through each set of points in half.
  20. john c

    john c New Member

    Messages:
    25
    Location:
    SC
    Cool! Ok, I'll try that! When I get a new dryer I'll probably switch that over to gas to free up a 240 breaker for the pump. I'll post an update. Thanks!
Similar Threads: burned pressure
Forum Title Date
Pumps and Tanks Well Forum & Blog Burned out pressure switch on shallow well jet pump Nov 12, 2012
Pumps and Tanks Well Forum & Blog Burned by pump co? Desperately need advice on what to do next Apr 15, 2012
Pumps and Tanks Well Forum & Blog Power went out for about 24 hours and now I have no water and no pressure. 10 minutes ago
Pumps and Tanks Well Forum & Blog Bouncing pressure switch Sunday at 3:51 AM
Pumps and Tanks Well Forum & Blog Dielectric union at pressure tank or not ? Nov 17, 2014

Share This Page