Inverter for my split level heat pump

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Comments

  • VicVic Solar Expert Posts: 2,976 ✭✭✭✭
    vince said:
    The input voltage on the inverter was good as indicated by the green led and measuring the voltage directly. As my load on the inverter is known and only involves the heat pump, mostly staying in the 500-800 watt range, the wiring size and breaker is ok. I got the 3000w inverter upon the advice of a cotek technician who didn't belief that the load could be that low for a heat pump and thought that I overloaded the 1500w inverter.


    OK vince,

    You are using a WBjr,  with a shunt in the negative lead of the battery,  IIRC.

    There should be a display on the KID,  that shows the battey current.  Have you watched the battery current shown on the KID,  at the moment that the Heat Pump starts?   

    These Inverter Heat Pumps should have little or no surge,  but it might be good to look at the current from the battery.

    Your comment,   "   ...   The cotek 3000 gives me an orange fault stating that the start up process is abnormal and does not proceed from there   ...   "

    Am not sure what the start up process is,  but,  if it is the start up when you switch the inverter DC input breaker to on,  it is possible that the inrush current into the inverter's input capacitors might cause the DC voltage into the inverter to sag so much that the inverter gives up,   and Faults,  or something  ...

    Do not know exactly.   Will try to download the manuals for the Cotek 1500 & 3000,  and try to see more about the recommended cable sizes,  etc.

    FWIW,   Vic

    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH [email protected], 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • vincevince Registered Users Posts: 79 ✭✭
    edited May 2016 #33
    I monitored the output on the Kid and during the startup of the heatpump, the output increased from a few amps to 13-14 amps or up to 850W as reflected on the input LED of the inverter. I don't belief the problem is the heatpump, as I replicated the same behavior when I hooked up a travel iron, a nice resistive load of 650 W. I'll try tomorrow to make a direct connection to the battery bank, bypassing the rest of the system, and double the wire size and see if the results remain the same. BB left a link to these inverters manuals in post above.
    The startup process involves a couple of beeps, a checking process and this does not happen.
    Sunpower 3 x 435 watt panels, 48 v 215 AH battery bank (Sam's club), Midnite Kid and WBjr, Fujitsu 9RLS3 split duct AC, Outback FX 3048T + transformer 2000W 120/220V, GrapeSolar Fridge.
  • VicVic Solar Expert Posts: 2,976 ✭✭✭✭

    Hi vince,

    Thanks for the reply.

    It is not exactly clear when you are getting that Orange LED indication.  Is that when the Inverter is powered-on with the On/Off switch on the inverter?   Does it always do this?

    Have you tried disconnecting all AC loads on the output of the inverter,  to see if the Orange LED still lights?

    I DO agree that in the Table of wire sizes and Inline Fuses for the 1500 & 3000 W -248 inverter it does read as you stated.   The Fuse ratings are really too high to protect the stated cable size ...     for the 1500  (#10 AWG and 90 A fuse IIRC),  and  #6 AWG and 175 A fuse for the 3000 inverter.    IMO,  the Fuse sizes are too large to protect these cable sizes in a Fault condition.   But this is probably not the issue that you seeing,  with the Orange LED.

    You did mention a 50 Amp breaker,   is this breaker in the DC cable connected to the input of the inverter? 

    The steady Orange LED may  indicate that there is something wrong with the inverter,  itself.

    Has the Orange LED always illuminated when you power-up the inverter?

    Thanks,   Good Luck,   Vic

    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH [email protected], 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • vincevince Registered Users Posts: 79 ✭✭
    Yes, the self diagnosis step never completes regardless of whether there is a load connected, and results in the orange light. Today I hooked up each converter directly too the battery bank, no connection to the rest of the system and used 4 gauge cables, 4 ft long plus a ground wire. As a load I used a nice resistive load, e.g. a travel iron. Replicated the same malfunctioning I have been experiencing with each inverter. My conclusion is that it is a problem with each inverter. Now I have to deal with the attitude that this is an highly unlikely occurrence and that it must be my system.
    Sunpower 3 x 435 watt panels, 48 v 215 AH battery bank (Sam's club), Midnite Kid and WBjr, Fujitsu 9RLS3 split duct AC, Outback FX 3048T + transformer 2000W 120/220V, GrapeSolar Fridge.
  • vincevince Registered Users Posts: 79 ✭✭
    Update. Was able to hook up an Outback FX 3048T inverter and everything performed as dreamed after configuring the Mate (an unexpected extra expense). AC on all afternoon (temps above 90) and with fridge and fans running, battery still topped off at end of day, hurray. Inverter is able to run the heat pump at 400-500 W at low fan and conservation settings (low noise outdoor unit and energy conservation mode) until desired temp is reached and total load was supported by the panels. The CC Kid was warm but not excessive. Both Cotek inverters were send of to their repair facility in TN (makes me understand why I got so little tech support from the people in WA), hopefully resulting in a refund. I like the fact that the outback is very quiet and with the low noise of the indoor and outdoor units, the experience of running the AC is remarkably pleasant.
    Sunpower 3 x 435 watt panels, 48 v 215 AH battery bank (Sam's club), Midnite Kid and WBjr, Fujitsu 9RLS3 split duct AC, Outback FX 3048T + transformer 2000W 120/220V, GrapeSolar Fridge.
  • Dave AngeliniDave Angelini Solar Expert Posts: 4,844 ✭✭✭✭✭
    Pleasant is an understatement! Good luck!
     Use the best equipment offgrid, always!  Cheap financial advice!
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

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