Inverter Power Save Mode

LukeN4HisDestNELukeN4HisDestNE Registered Users Posts: 12 ✭✭
Hi folks. I'm looking for a way to use my inverter in power save mode to run my well pump. The problem is that the well pump has a soft start motor and the inverter requires at least 25 watts to kick on and power the load. Soft start motors draw 0 watts at start up and therefore won't signal enough power to the inverter to fully kick on. I need to wire a separate load in between my pressure switch and pump that draws around 25-100 watts. The problem is it's a two wire pump. No neutral wire runs to the pressure switch. I cant think of a load that small that doesnt require neutral. Anybody know of a solution, without having to go through the hassle of diggining up the old 2 wire running from the house and replacing with 3 wire? Any help much appreciated!
«1

Comments

  • westbranchwestbranch Solar Expert Posts: 4,822 ✭✭✭✭
    a 25W incandescent bulb?
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge, Hughes1100 Sat Modem
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • LukeN4HisDestNELukeN4HisDestNE Registered Users Posts: 12 ✭✭
    Thanks for the suggestion! Would it not require a neutral wire?
  • mcgivormcgivor Registered Users Posts: 1,190 ✭✭✭✭
    edited December 2016 #4
    That would work, put the 25W incandescent lamp across the input of the soft srart, when the pressure switch commands  the pump to run, the inverter will see the 25W load and power up, the voltage of the lamp should of course be the same as the pump, no voltage was mentioned.
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • LukeN4HisDestNELukeN4HisDestNE Registered Users Posts: 12 ✭✭
    mcgivor said:
    That would work, put the 25W incandescent lamp across the input of the soft srart, when the pressure switch commands  the pump to run, the inverter will see the 25W load and power up, the voltage of the lamp should of course be the same as the pump, no voltage was mentioned.
    Thank you! I've only had experience wiring light fixtures with cfl bulbs. I didn't know incandescent did not require a neutral. Just to clarify I have two wires going to the pump, both hot, each carrying 120v. So I can wire the incandescent lamp to either leg and close the neutral wire? That seems so strange to me. I thought electricity required a circuit to travel? Thanks again!
  • mcgivormcgivor Registered Users Posts: 1,190 ✭✭✭✭
    An incandescent lamp needs no neutral just the required voltage, if the inverter is pure sine wave, is is common practice to ground one leg to establish a neutral for safty reasons, but will work without, PDF for reference.
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • HorseflyHorsefly Registered Users Posts: 250 ✭✭✭
    @LukeN4HisDestNE - So you have a 240V pump, and I assume the pressure switch is double-pole (both legs of the 230V). If so, then you can take the pump side connection for one of the two legs, and connect that to the 25W incandescent lamp, and hook the other side of the lamp to neutral. Then you have a 120V circuit for the light that turns on whenever the pressure switch turns on.  That should be enough for the inverter to come out of search mode and power the pump.

    Turns out, I've been thinking about this same situation, as I have a pump that I want to put a soft-start on (discussed in another thread). My current pump is 120V, but we are planning on putting a 240V two-wire soft-start pump in, just like you. Is yours a Gandfos SQ pump?

    Steve


    Off-grid cabin: 6 x Canadian Solar CSK-280M PV panels, Schneider XW-MPPT60-150 Charge Controller, Schneider CSW4024 Inverter/Charger, Schneider SCP, 4 x Vmax XTR12-155 12V, 155AH batteries in a 2x2 24V 310AH bank.
  • LukeN4HisDestNELukeN4HisDestNE Registered Users Posts: 12 ✭✭
    @Horsefly Yes Steve, I have the Grundfos SQ pump! Been working great so far. Had it about 6 months I think. 1 hp and pulls around 8 amps maximum. Runs for less than a minute and pumps my 20 gallon pressure tank. Funny thing, half the battle getting it installed was convincing the installer that it did NOT require a control box. Only the SQE does. As I didn't need constant pressure control for my setup I opted out of the SQE.

    Anyway going back to your comment, you said "hook the other side of the lamp to neutral" but I have no neutral going to the pressure switch. Just two hot legs and a ground wire. I'm in Virginia so my ground and neutral are isolated.
  • mcgivormcgivor Registered Users Posts: 1,190 ✭✭✭✭
    As no voltage was mentioned, the lamp voltage must be the same as the pump voltage, even 230V systems can have a ground established at the inverter. Isolated 240V on a split phase grid systems use no neutral. 
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • LukeN4HisDestNELukeN4HisDestNE Registered Users Posts: 12 ✭✭
    @mcgivor Thanks so much for the info. Neither of the legs are grounded on the Inverter. Here is the wiring diagram of the inverter, but the netural line does not make its way out to the pressure switch 50 feet away from the house. So it will be safe then to just wire one of the hot legs to the lamp and do nothing with the neutral side of the lamp? Just making sure. I like to triple check things before I wire them.
  • mcgivormcgivor Registered Users Posts: 1,190 ✭✭✭✭
    So your inverter is split phase, no problem either use a 230V lamp or if you can't find one 2 X 120V in series will work, no neutral is required.
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • LukeN4HisDestNELukeN4HisDestNE Registered Users Posts: 12 ✭✭

    @mcgivor Yes it is split phase. So then connect one hot wire from pressure switch to hot of the first lamp. Connect other hot wire from pressure switch to neutral of the first lamp. Then connect the hot of the first lamp to neutral of the second (+240v). Finally connect the hot of the second lamp to one of the hot wires going to the pump, then the neutral of the second lamp to the other hot wire going to the pump. That would seemingly insure a 240v transfer? Just making sure. Thanks again!


  • mcgivormcgivor Registered Users Posts: 1,190 ✭✭✭✭
    A picture is worth a thousand words, connect 2x12V lamps in series in leu of a 240V, I would simply place them over the pump input, or across the pressure switch downstream side, whatever is more convenient same results.
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • LukeN4HisDestNELukeN4HisDestNE Registered Users Posts: 12 ✭✭
    Oh I see, funny I didn't think of that, same results though, true. I just need to make sure and get long lasting bulbs and check periodically. If the bulbs go out the pump would continually try and kick on but wouldn't get enough juice from the inverter. I saw it happening when I first tried power saver mode. The controll panel of the inverter showed an output voltage fluctuating and I fear it would burn up the pump. Anyways, thank you so much, you've helped a million!
  • mcgivormcgivor Registered Users Posts: 1,190 ✭✭✭✭
    The power saving mode sends pulses to check if any loads greater than the setpoint are present, this is normal, when the pressure switch closes the lamps will become visible to the inverter and it will power up. Keep some spare lamps as incandescent is fast becoming extinct, you could use any other load though, the lamp method is one example.
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • HorseflyHorsefly Registered Users Posts: 250 ✭✭✭
    @Horsefly Yes Steve, I have the Grundfos SQ pump! Been working great so far. Had it about 6 months I think. 1 hp and pulls around 8 amps maximum. Runs for less than a minute and pumps my 20 gallon pressure tank. Funny thing, half the battle getting it installed was convincing the installer that it did NOT require a control box. Only the SQE does. As I didn't need constant pressure control for my setup I opted out of the SQE.

    Anyway going back to your comment, you said "hook the other side of the lamp to neutral" but I have no neutral going to the pressure switch. Just two hot legs and a ground wire. I'm in Virginia so my ground and neutral are isolated.
    Good to know how pleased your are with the SQ!  I'm looking at a 1/2 hp model for our future pump. My pump guy seems pretty sharp, so I don't think I'll have to go through the battle you did. At least I hope not!

    It hadn't occurred to me that your pressure switch would be far away. My pressure tank and switch are right next to where the inverter will be. I think @mcgivor has the right solution. If the environment out there is not good for incandescent lamps, maybe there is a different resistive load you could come up with to put out there.

    Steve

    Off-grid cabin: 6 x Canadian Solar CSK-280M PV panels, Schneider XW-MPPT60-150 Charge Controller, Schneider CSW4024 Inverter/Charger, Schneider SCP, 4 x Vmax XTR12-155 12V, 155AH batteries in a 2x2 24V 310AH bank.
  • LukeN4HisDestNELukeN4HisDestNE Registered Users Posts: 12 ✭✭
    @mcgivor @Horsefly I was planning on just wiring two receptacles so I can use standard plugs. This should work, right?
  • mcgivormcgivor Registered Users Posts: 1,190 ✭✭✭✭
    Yes, correct plug one 120V lamp into each receptical. NOTE I don't use the term bulb, that is for tulips and such, old school teachings and hot refers to temperature, the correct term is live, we were sent home with no pay if we used the wrong terminology ......yeah the old days.
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • LukeN4HisDestNELukeN4HisDestNE Registered Users Posts: 12 ✭✭
    @mcgivor LOL I understand the distinction. Speaking of the old days I was at my aunts house last year up in Kokomo, Indiana. One of her light switches had gone out. We went and got her a new one and took the old one out. It was the old turn knob type. I pulled it out and examined it. It was dated 1908. Both wires were black, frayed and charred. No visual distinction between the line and load.
  • LukeN4HisDestNELukeN4HisDestNE Registered Users Posts: 12 ✭✭
    @mcgivor LOL yes I totally understand the distinction. I could use two LED lamps, correct? I won't have to worry about replacing them as often.
  • BB.BB. Super Moderators Posts: 26,758 admin
    You can try it--But it is possible that any of the LED lamps will be too low of power to reliably pull enough energy to kick the inverter out of search mode.

    You could try a small heating element instead--Or heavy duty/long life bulbs.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • LukeN4HisDestNELukeN4HisDestNE Registered Users Posts: 12 ✭✭
    @BB. Thanks Bill!
  • mcgivormcgivor Registered Users Posts: 1,190 ✭✭✭✭
    @BB. Mentioned Led lamp probably won't work and this is true, they mostly have a switching transformer to bring down and rectify the voltage to drive the LED, I was thinking an appliance lamp, the one's used in ovens, should be robust and long lasting.
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • littleharbor2littleharbor2 Solar Expert Posts: 635 ✭✭✭✭
    There are 50 and 100 watt LED's if you need a larger load. Just saying, not recommending.

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric, 700 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

  • mcgivormcgivor Registered Users Posts: 1,190 ✭✭✭✭
    How about 2 cheap 30W soldering irons, mounted so they would not burn anything of course,  just simple resistive  loads without  vulnerable flimsy filaments.. 
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • mike95490mike95490 Solar Expert Posts: 7,249 ✭✭✭✭
    Wire 3 sockets in series (as if you had 360Vac) and use 3, 75w or 100w bulbs. They will run ~2/3 voltage and should last forever.
    Beware the halogen bulbs unless they claim to be dimmable, some have a diode in them.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • mcgivormcgivor Registered Users Posts: 1,190 ✭✭✭✭
    Good idea mike!
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • e12doe12do Registered Users Posts: 7 ✭✭

    You are going about the problem in the wrong way. Get a second pressure switch and install it in the water system. hook up a 120 volt water heating element up to the switch.  When the pressure drops the the element comes on. Put the element in a bucket of water or use the lower one in your hot water heater if you have one. The element will come on when the switch activates., there are two pressure switches (1) is 30 to 50 psi (2) is 40 to 60.

  • LukeN4HisDestNELukeN4HisDestNE Registered Users Posts: 12 ✭✭
    @mcgivor Update: Two 14.5 Watt LED bulbs (lamps) did the trick! Wired the receptacle in series and split the tabs. Didn't think of it before hand but the bulbs blinked in sync with the split phases. Here's a pic
  • mcgivormcgivor Registered Users Posts: 1,190 ✭✭✭✭
    Good to hear it works, keep an eye on the LED's if they fail you could always replace with incandescent.
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • BB.BB. Super Moderators Posts: 26,758 admin
    LED bulbs are "non-linear" devices... They may not respond to voltage and current in a simple manner. I would suggest using filament bulbs.. But if these LED bulbs work for you--That is great.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
«1
Sign In or Register to comment.