annoying light flicker when heat pump starts up

Discussion in 'General Discussions' started by eisensms, Oct 13, 2009.

  1. eisensms

    eisensms Member

  2. bob350

    bob350 New Member

    Interesting. This also appears to lessen the required size of a generator during a power outage.
  3. teetech

    teetech Member Forum Leader

    Assuming there is not a problem with EW electrical, this should solve your issue. The Intellistart is a soft start device designed to cut your LRA by 60%. It can be installed any unit with a scroll compressor, 2 stage or single stage. Age should not matter.
  4. Looby

    Looby Member Forum Leader

  5. eisensms

    eisensms Member

    Well, let's order two and split the cost, OK?
  6. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    Looks promising.

    I'd like independent corroboration of reduced amps. If the thing works as advertised it could save thousand$ of standby generator dollars.

    My own Waterfurnace has a nameplate LRA of 82, which contributed to my selection of a 24 KW 1800 RPM standby generator. After that 82 LRA spike my WF settles down to using 6 amps in cooling, 8 amps heating in low stage.

    The 6 amp WF hits the generator harder (judging by ear) than my 5600 Watt clothes dryer...
  7. flynmoose

    flynmoose New Member

    Anyone order one of these yet?

    I'm definitely interested and am curious about cost and results.
  8. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    I keep looking

    For Copeland to mate a Scroll compresor to an ECM drive.
  9. teetech

    teetech Member Forum Leader

    Variable speed compressor will be the next big leap for GEO.

    I have installed intellistart and would recommend it for cutting LRA. Also a relay and capacitor from Copeland (sized for your compressor) would help.
  10. flynmoose

    flynmoose New Member

    Anyone willing to quote ballpark for what retrofitting a Intellistart onto a Synergy3 system would run (parts & labor)?
  11. ciws14

    ciws14 Member

    Good point. Nordyne/ Broan has started with their iQ Drive blowers & compressors on their conventional A/C & Heat Pumps. It is marketed under several names. Looks like it won't be much longer (if it hasn't already) before it's in Geo's. I am anxious to see how well they work and efficiency.
  12. mseifert

    mseifert Member

    Re: Intellistart

    On the current thread: "Aux Furnace Heat vs Aux Electric Heat" this topic is also being discussed. One post by Pine Mountain Energy states
    In that post I am looking for a solution for keeping loads within the range of my generator and not overloading it. gabby recommended an electrical demand controller. A demand controller would limit the maximum amps drawn at one time by prioritizing use and spreading the demand for electricity more evenly over a period of time. Here is an example: I talked with the company and cost would run me approximately $1,500 (not including installation - which would push it probably close to $2,000).

    I would prefer the IntelliStart soft start since I expect it would be way less expensive and simpler. The demand controller is a great solution but it would have all 220 loads running through an additional panel (so a relay can cut off power to the appliance) which means significant re-wiring cost.

    But will the IntelliStart cause a mini brown-out every time it starts? As engineer said:
  13. gabby

    gabby Member Industry Professional Forum Leader

    Go to WF wed ask them to send you the spec sheet on that device, as well as test results on different unit sizes. This should answer your questions...if anything confuses you, post what you need explained and someone here will be able to put it in layman terms.
  14. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    That would probably be handled by an electrician rather than HVAC contractor since it involves high voltage.
  15. teetech

    teetech Member Forum Leader

    Intellestart is a softstart device it does not cause a brown out, it quite simply reduces your start amps (LRA). It has been tested and they claim 70% reduction I always prefer to pad a little and would use a 60% number.

    So figure your LRA would be reduced by 60%.
  16. mseifert

    mseifert Member

    I was equating "volt drop" to a brown out. I was making an assumption that the soft start contributed to this. I guess I don't know how a soft start really works.
  17. gabby

    gabby Member Industry Professional Forum Leader

    The soft starts I have used are for three phase systems, not single phase, but I will assume they operate similar. The full voltage is applied but the phase relationship to capacitor or inductor is altered to simulate a variable resistance on start. I haven't seen the motor circuit for the heat pump so I will make some calculated guesses. There is a run capacitor and a starting capacitor. The starting capacitor produces a large current to start the mass of the motor in motion until a speed is attained that drops out the start winding of the motor and shifts it to the run circuit.

    If you can shift the phase current coming through the capacitor on start, you can essentially lower the current that leads the voltage. This can be achieved in at least two ways. The first is using a saturable reactor (large magnetic coil), or the second a SCR control circuit acting as a current regulator. In both cases you are essentially making the load a variable resistance, rather than an inductive load by the offsetting phase (voltage leads the current), or the current regulator (SCR or Triacs--solid state devices). As you lower resistance you increase the current, so this ramped up current must happen in a relatively short period of time to get out of the start winding circuit and into the run winding. With this process you replace the instantaneous spike in current on start (LRA), with a steady state ramp up in current to achieve the speed to drop from start to run.
    In three phase systems they vary the frequency of the three phases that are offset by 120 degrees between phases, and limit the current to a ramp function through triacs, achieving the desired current restriction and speed....aka variable speed drives.

    In all cases there is a minimum current that must be maintained on start....mass needs a kick in the pants to start moving or it just sits there humming and soon smoking.
  18. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    Single phase compressor only has one capacitor placed across start and run terminals.

    A source of confusion may be that air source heat pump capacitors have a third connection - the same can provides both a small capacitor (~5 uF) for the outside fan motor and a much larger capacitor (~40 uF) for the compressor.

    My understanding is that the object of the capacitor and start winding is to create a temporary imbalance during start in the rotational force applied to the armature so that it starts moving in one direction rather than just vibrating at 60 Hz, and also ensure the correct direction of rotation.

    The very nature of 3 phase, the delay in peak voltage applied to each leg avoids this need.

    Don't quote me on this, especially if it turns out to be wrong
  19. gabby

    gabby Member Industry Professional Forum Leader


    You are correct about direction. The lower resistance start winding is the reason for the large current spike with full voltage applied.
    If you bypass the compressor capacitor, it could turn in either direction. Some motor projects we manually start the motor spinning before applying power, controlling the spinning direction....this also happens when the capacitor fails.....wrong direction.

    One can create a 3 phase generator to power a lathe with a 10 horsepower motor, spinning it with a 1-2hp 220 volt motor....cheaper than buying a transformer, or adding three phase service for 1 or 2 machines at home.
  20. teetech

    teetech Member Forum Leader

    The compressor starting (high amps) causes the voltage drop, the Intellistart reduces the starting amps.

    We used to add a relay and start capacitor recommended by the compressor manufacturer (not the generic hard start kit) to reduce the starting amps.

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