Need some thoughts on a relay

inthejungle
inthejungle Solar Expert Posts: 91 ✭✭
in Off Grid Solar & Battery Systems #1
I need a bit of help coming up with a relay to sort out a problem.


I currently have a shurflo 2088 pump hooked up with a float switch and wired in via relay to my breaker box. Reason for a relay is that the float switch is meant for 110 so I wanted to make clean breaks and put it on a relay to extend the life.

I have a battery bank of 350Ah Rolls, currently my absorption voltage is set to 15v. There has been several times that I have heard the pump kick on while the charger is absorbing. Well lets just say that you can tell that the pump does not like that.

I am wondering if anyone can point me in the direction, I would like to setup a relay or something to only allow the pump to run at a certain voltage. I am not always around and don't want that pumped to get messed up.

I found something like this, but relay does not open until 18v

http://www.factorymation.com/Products/Voltage-Monitoring-Relays/HRN-34.html


Any thoughts?

ITJ
In Niger, trying to keep a LG FMA 102NAMA fridge(This has the inverter compressor) backed up with solar using a Victron Multi-Plus Inverter/Charger Compact 12v 1600w with a 70a charger built in.I want to back it up for 4-8 hours. I am also running a few O2 cool fans and a few Thin Lite LED's of my batteries for when the grid is down so my kids can sleep.
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  • jcheil
    jcheil Solar Expert Posts: 722 ✭✭✭
    #2
    Re: Need some thoughts on a relay

    What charge controller are you using? Most of the better ones have AUX contacts that can drive a standard or solid state relay based on battery voltages and charging states.
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
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  • inthejungle
    inthejungle Solar Expert Posts: 91 ✭✭
    #3
    Re: Need some thoughts on a relay

    Thanks for the quick response

    Currently I am using the OutBack FM 80, with the FM80 can you have two Aux settings running at one time?

    I already have the vent fan setup, if I used the aux setting on the FM80 only problem with that is what happens when the system is sleeping or not currently charging?

    Do you think it would be better to have the water pump and relay independent of the charge controller?

    If I used the FM80 what do you think would be the best way to set it up?

    Thanks
    ITJ
    In Niger, trying to keep a LG FMA 102NAMA fridge(This has the inverter compressor) backed up with solar using a Victron Multi-Plus Inverter/Charger Compact 12v 1600w with a 70a charger built in.I want to back it up for 4-8 hours. I am also running a few O2 cool fans and a few Thin Lite LED's of my batteries for when the grid is down so my kids can sleep.
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  • jcheil
    jcheil Solar Expert Posts: 722 ✭✭✭
    #4
    Re: Need some thoughts on a relay

    I am gonna have to pass this on to one of the more experienced people here but I am pretty sure there is a way to control AUX based on charge state but I think it only has one.
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
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  • PhilS
    PhilS Solar Expert Posts: 370 ✭✭✭
    #5
    Re: Need some thoughts on a relay

    Maybe I'm misunderstanding something, which is not unusual.

    You are using a 12V Shurflo water pump hooked to your battery bank? I have the same setup for my 'backup' water pressure, should my 115V jet pump fail (which seems to only happen when we have housesitters minding the homestead).

    What do you mean by '... the pump doesn't like...' the higher 15V? I can't remember any 12V things that complained about 15V. Does it seem to run too fast? Or make an odd noise?

    Phil
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  • waynefromnscanada
    waynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    #6
    Re: Need some thoughts on a relay
    PhilS wrote: »
    Maybe I'm misunderstanding something.

    What do you mean by '... the pump doesn't like...' the higher 15V? I can't remember any 12V things that complained about 15V. Does it seem to run too fast? Or make an odd noise?

    Phil
    My thoughts as well. Something, or a lot, not making sense to me or I'm not understanding, including the requirement of a relay to provide for a "clean break". I can see using a relay to take the load off the float switch contacts, but if that switch doesn't already make a "clean" break, it will cause the relay to chatter on make and / or break.
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  • inthejungle
    inthejungle Solar Expert Posts: 91 ✭✭
    #7
    Re: Need some thoughts on a relay

    Thanks everyone for your thoughts,

    The pump when run at 15v, sounds very bad and seems to be over working. I can not seem to get my hands on a spec sheet to see what the operating range is. I thought that 15v would be OK.

    The purpose of the relay is that 110v float switch is meant for 110 and the 12v relay is meant for 12v. In my mind 110 is easier to quench and 12v takes a bit more to quench it. With that being said I didn't want the 110 float switch to have problems so I put the relay on it to do most the work quenching the power.

    ITJ
    In Niger, trying to keep a LG FMA 102NAMA fridge(This has the inverter compressor) backed up with solar using a Victron Multi-Plus Inverter/Charger Compact 12v 1600w with a 70a charger built in.I want to back it up for 4-8 hours. I am also running a few O2 cool fans and a few Thin Lite LED's of my batteries for when the grid is down so my kids can sleep.
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  • stillchillin
    stillchillin Registered Users Posts: 59 ✭✭✭
    #8
    Re: Need some thoughts on a relay

    i'll try I have the same controller and there is only one aux contact. Most motors are rated nameplate voltage plus or minus 10% so 15v is more than 20%. maybe you could wire the fan and relay so when charging the fan comes on and the circuit to the pump is open (disabled) this can be done with one relay with a SPDT relay or better yet a DPDT relay using one set of contacts to power the fan and one set to power the pump the normally closed contact in the pump circuit the normally open contact in the fan circuit. Try a RIB relay they come in every voltage and contact configuration you can come up with. Hope that helps. Stillchillin
    18- 235 W Kyocera panel, 12- 4-KS-25PS Rolls 1350 Ah, Magnum MS4448PAE, ME RC50, ME AGS, Outback FM 80, Generac 8KW LP generator, 6.5 Honda Portable generator
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