Envision - Aux Heat Supply

Discussion in 'General Discussions' started by JRBGEO, Jan 16, 2011.


    JRBGEO Member Forum Leader

    I have a quick question on the WaterFurnace Envision series (NDV049) Aux Heat Supply.

    I am in the process of installing a WEL (Web Energy Logger) for my system. The system diagram can be viewed below:

    Energy and Thermal data for Bethencourt Residence - WEL0444

    I have 3 Clip On Run Monitors from CR Magnetics to track ON/OFF status for the circulator pump, the GSHP and the conductor wire on the Aux Heat Supply.

    My question is : I have noticed that the GSHP and the ciruclator pump run monitor flips from 1 to 0 (ON/OFF) however the Aux Heat Supply is always 1 (ON).

    My system is running always on Stage1 - sometimes Stage 2. Never Stage 3.

    Could there be another device drawing power on the Aux Heat Supply besides the Electric Heaters?

    I wonder if there is a way to wire this differently so I can track ONLY when the Electric Heaters come on?

    We plan on monitoring the system staging at a later date but for know I would like to identify what else could be drawing power - all the time - on this conductor.

    Any insight would be appreciated.

    WEL works like a charm. I am finding a lot of good stuff about my setup.

  2. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    The only thing that comes to mind is whether the control voltage transformer is supplied from that circuit - it doesn't draw much, though
  3. geome

    geome Member Forum Leader

    The blower on our packaged unit is on the heat strip breaker. Are you running continuous fan?

    JRBGEO Member Forum Leader

    Aux Heat Supply....

    I am not sure. I do remember sometime ago talking with my WaterFurnace installer and he stated there were other things in the Aux Heat side....not just the electric heaters...

    Is there a way to determine this easily? That is if I am running "continuous fan"?

    Now that I have the WEL installed I am discovering these things. The other issue is that when the Envision shuts off altogether - that is Stage 1 or 2 - the unit is totally quiet and I cannot even hear anything else running.

    I would imagine I would hear a fan running right?
  5. Looby

    Looby Member Forum Leader

    As geome said, the standard WF-recommended installation
    (with WF electric heat strips) puts the blower on the same
    circuit breaker as the heat strips. That way, you'll still have
    emergency heat if the compressor breaker trips.

    JRBGEO Member Forum Leader

    Makes sense now

    Thanks Looby and others for your posts. That makes perfect sense now.
  7. geome

    geome Member Forum Leader

    The fan (blower) selection is done at the thermostat. We have the following options:

    "On" runs the fan for continuous air circulation even if the thermostat isn't calling for heating or cooling.

    "Automatic" runs the fan when the thermostat calls for heating or cooling.

    "Circulate" may run the fan periodically for a portion of the hour in addition to when the thermostat calls for heating or cooling.

    Keep asking questions:)

    JRBGEO Member Forum Leader


    Thanks geome...I checked my WF thermostats. The FAN is on AUTO - both zones.

    So based on this it should only be drawing power when a call for heat / or cool is done right?

    This brings me back to my original question then ....should there be power flowing through the Aux Heat supply conductor when STG 1 or 2 are OFF??? I understand the fact that the fan / blower is on the same circuit where Aux Heat supply is but if the thermostats have the FAN set to Auto then the blower should go off when STG 1 or 2 is off...right?

    Now I am confused...:confused:

    Last edited: Jan 16, 2011
  9. moondawg

    moondawg Member

    Is your unit zoned? Is the zone controller powered off the aux circuit?

    My guess is that if #1 is YES then #2 is YES as well.
  10. JRBGEO

    JRBGEO Member Forum Leader

    Moondawg wrote:

    Yes I have a Zone control panel from Honeywell. I am guessing this is probably what is drawing power when STG 1 or STG 2 shuts off.

    I can't imagine the power draw coming from the fan/blower as I cannot hear anything running once the system shuts down...

    Can the zone controller panel be powered in a separate circuit - independent of Aux Heat supply?
    Last edited: Jan 17, 2011
  11. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    Zone controller likely uses control power - the 24 Vac transformer I discussed earlier

    Is there a way you could mount your use sensor (I assume it is a current clamp) downstream of the control xfrmr load. Is there a way to calibrate the sensor so it doesn't consider a very small current, perhaps 0.1 amps or less, as an active load?
  12. JRBGEO

    JRBGEO Member Forum Leader


    I am using a CR Magnetics clip on current switch (from Phil's website welserver.com).

    I spoke with my WF rep and it does look like it is some low voltage transformer that is on that circuit. He is going to swing by next tuesday and change the way it was wired originally so only the Aux Heat supply is on that circuit. He stated it was an easy change.

    I don't think I have too much wiggle room as far as what I can do with the current switch. If there is power going through the conductor the WEL will show a 1 otherwise it goes to zero. I thought about tinkering as well with the scale and offset settings on the WEL itself but what if the unit goes into Aux heat...? Very unlikely...it is probably cleaner for the WF rep to change the wiring so only Aux heat supply is on this conductor and nothing else...


    Last edited: Jan 17, 2011
  13. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    The trouble with doing that is that he'll move the transformer to the compressor branch circuit. If by some chance the compressor fails so as to trip the breaker you'll have no heat.

    This doesn't happen often, but it is a concern in cold climates
  14. Looby

    Looby Member Forum Leader

    From the schematic, it appears that it should be possible
    to hook a clamp probe onto the wires directly powering
    the heating element -- inside the Envision upper cabinet.

    Caution: Lethal voltages inside. Leave this to a pro if
    you're not 1000% certain of what you're doing.

  15. JRBGEO

    JRBGEO Member Forum Leader

    Not to worry I'll leave this to the WF installer. I'll touch base with him again next week on what he plans to do. I know...the last thing I need is have the compressor fail and have no Aux heat either.

    Looby wrote:

    I believe this is what the electrician did when he installed the CR Magnetics clip on current switch. He installed the clip on switch right on the conductor for the heating element. When you open the top panel in the unit (front panel) there is a cabinet at the top where the wiring for the Aux heat element is. It may be a matter of moving this clamp to another wire...we'll see....


    Last edited: Jan 17, 2011

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