Intellistart causing an open 'run' circuit (WF NDV049)?

Discussion in 'General Discussions' started by mkutch, Jan 24, 2017.

  1. mkutch

    mkutch New Member

    Some history:

    Waterfurnace NDV049 4-ton system, installed and running problem-free for 8 years. I am located in Michigan. Geo-unit is in a conditioned, unfinished basement. Avg temps around 60-65* in basement. Avg temps outside for Jan are 10’s lows and 20s/30s highs (although the last 2 weeks we’ve seen unusually warm 40s….no complaints here.).

    Back in October I had an Intellistart soft-start module installed to enable my portable Generac to run the Geo if/when we have a winter power-outage.

    System continued to run problem-free 1.5 months until late-November when I first encountered a Comfort Alert fault which shut-down the compressor and ran the system on fan+auxheat until I ‘caught’ the issue. (My t-stats do not alert me when a fault occurs…. I have to physically ‘see’ the red-blinking light on the geo-unit’s status-panel.)

    I didn’t think much of it initially and reset the system (cycled the breakers off/on) before realizing I should have pulled the code(s). Ah well.

    System re-set just fine and operated normally for another month, when over the December holidays I caught it fault-out again. Comfort-Alert Yellow Code 7, ‘open run circuit’ Current only in start-circuit. At the time I had no ability to mess with it given holiday obligations, so re-set the system and again it operated normally. I fully expected it to fault again, just didn’t know when.

    Then again on Friday 20-Jan (and lastly now on Sunday 22-Jan), I caught it fault-out. Both again the CA Yellow Code 7 of course. Consistency is good.

    The troubleshooting information for Code-7 are as follows:
    1. Open circuit in compressor run wiring or connections.
    >>Check Wiring and connectors between supply and the compressor “R” terminal.
    2. Compressor run winding is damaged.
    >>Check compressor motor winding resistance.

    On Saturday (before Sunday’s ‘fault’), I had the opportunity to perform some checks. I first started with all of the wiring that I added to/from the Intellistart, double-checking everything to the schematic. Which, all of these checked-ok / fully engaged, tightened, etc. I even swapped an end-spade thinking maybe there was a bad crimp on the terminal. I then checked all the wiring to/from the “R” terminal. And, for grins, also looked at the run capacitor to verify no ‘jiffy pop’ ballooning had started… (Capacitor looked good.) So with my connections verified, I then turned to looking at the compressor windings.

    Checking the compressor winding resistance:

    Start Winding Terminal “S” to Common “C” = 1.1 ohm
    Run Winding Terminal “R” to Common “C” = 0.3 ohm
    Run “R” to Start “S” = 1.4 ohm
    C-to-ground, R-to-ground, and S-to-ground = infinite / open circuit

    My understanding is that the sum of the start and run winding resistance should equal the resistance across R-to-S. If it is, then the compressor winding is OK. If not, then the compressor winding is damaged. In my case, they are equal, so I have some confidence the compressor windings are ok.

    At that point on Saturday I had to stop, and after re-affixing the various connections I re-set the system to see if there was any change. By some luck the system faulted again on Sunday, just a day later…. I say ‘luck’ because I had time to investigate further without hassles of doing it during the workweek. Looking again at the setup, recognizing that the ‘run’ circuit is fed through the Intellistart, and recognizing (coincidence or not) that my ‘fault-code 7s’ all started AFTER I installed the Intellistart…. I removed the Intellistart module and reverted everything to my conventional start/run wiring configuration. It is also important to note that I did NOT even think to check the LED on the Intellistart before turning-off the power and removing it... I actually completely forgot about the LED on the Intellistart until after I removed it and saw the LED-location... So no history on if/what was displayed on the Intellistart LED on any of the Code-7 'faults' I encountered. DOH. <shrug>

    Its been 24 hours and all is running OK, however, knowing that my ‘faults’ were not immediate (anywhere from 1-day – yesterday – to 1.5 months between faults), its difficult to say that anything is ‘fixed’ until a MUCH longer time-duration has elapsed.

    All of this brings me to the few questions:
    • Has anyone had an Intellistart (or SureStart or SecureStart or any other branded-name) ‘fail’ on them and cause an open run-circuit fault?
    • Is it plausible for the Intellistart to fail intermittently, thereby periodically not sending the current to the ‘run’ circuit?
    • Does the Intellistart have any trouble-shooting checks on it that I can perform (eg, resistances across its various terminals)?
    • Is there any replaceable items on the Intellistart? (I haven’t yet called WF to check on warranty-status, seeing that the Intellistart is barely 90-days used.)
    • What other possibilities can be the cause to the Comfort Alert tripping Yellow-7? And recommendations how/what to check on those other possibilities?

    Thanks much in advance,
    Last edited: Jan 25, 2017
  2. arkie6

    arkie6 Active Member Forum Leader

    The SureStart, SecureStart, and Intellistart soft starters are manufactured by Hyper Engineering ( ) . You might contact them and see if they can provide any input.
  3. geoxne

    geoxne Active Member Forum Leader

    Last edited: Jan 24, 2017
    mkutch likes this.
  4. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    We've had several Intellistart fails and so have stopped specifying them on systems below 4 tons. That includes nonIntellistart-branded variants such as Emerson SecureStart.
  5. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    Yes, but they run/start so nicely when they are working...o_O
    WF had 2 version, a smaller for the 2-3 tons, and the larger version for the 4-5 tons. The smaller version had the issue, I believe that they are now only putting the larger version in all models. Still not available for the 4 and 5 ton Optiheat, only the 3 ton.
  6. mkutch

    mkutch New Member

    How very familiar! This is a great description of my intermittent/random triggering of the CA Code-7. Interesting that WF Tech Support didn't mention this when I contacted them yesterday; the Tech Rep quickly (and only) pointed to a faulty Intellistart.

    Thank you to all for the feedback. I have some things to pursue....
  7. jk96

    jk96 Member

    MKutch do you know what your electric draw is when starting up with your intellistart? I also have thought about adding one for the same reason as you, in order to run from a generator in a power outage.
  8. mkutch

    mkutch New Member

    I do not; however I have tested my system with my generator -- Envision NDV049 4-ton unit paired to my Generac GP6500 (6500w continuous, 8000w peak) with the Intellistart -- and much to my giddy-like-a-schoolchild excitement, it successfully started and ran multiple times without even a hiccup. With my setup I calculated (estimated) that I was going to need 7700-7900w for startup, assuming the Intellistart's claims of course. So I knew it was going to be close with my existing generator; but, before purchasing a slightly larger genny I gave it a try and like I said, the Geo fired and ran on both stages just fine (no aux-electric heat, of course).
    jk96 likes this.
  9. ChrisJ

    ChrisJ Active Member Forum Leader

    I purchased the SureStart for my 3 ton W to A unit but have not installed it. My RLA is right at 16 which is on the cusp of the range for the 2 sizes of units.

    I called and they said to get the smaller one. Hopefully I'll be fine, I don't think my unit has a Comfort Alert fault system.

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