Utah Looking for some advice

Discussion in 'Quotes and Proposals' started by Palace GeoThermal, Sep 14, 2015.

  1. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    That is a big pump for only 9 gpm max flow needed. Make sure it is throttled back to the flow you need max, so you don't waste all the pumping power.
    The zone valves are good, have their end switch connected to the GV zone manager out of John Manning's store, so the pump shuts off when no zones are calling. Then you should have the most efficient set up I can think off.

    Check the control logic of the unit, the dip switches can usually set to minimize the blower run time prior to compressor start.
  2. geoxne

    geoxne Active Member Forum Leader

    Some Magna pump models have Start/Stop terminals that require an isolated end switch to control. I do not believe your model has it standard. Check to see if the expansion relay start/stop module is available for your specific model. Do not confuse with their other fancy -read $$$ "Geni" expansion modules that communicate to BAS systems also.

    If you are NOT using the end switch on the Zone Sentry for anything else you can wire each end switch in parallel to the Grundfos Start/Stop module.

    If you ARE USING the Zone Sentry end switch with 24v power than you will need the GVZM to isolated the 24v signal from each HP transformer and it will provide an isolated end switch to signal the Magna pump to start.

    The fan blows before the compressor starts because the thermostat told it to. The thermostat doesn't know the compressor is delayed. This is more noticeable with PSC fan motors as it blows full speed no matter what. You could wire in a time delay relay if it is particularly bothersome.
  3. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    Indeed, the manufacturers used to sell the "external on/off" for big $$$, at least now Wilo came to its senses and includes it as standard, don't know about Grundfos.
    At least with Waterfurnace, the thermostat does not turn on the fan, the unit does that when getting a Y1 signal. Your milage may vary.
  4. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    It was easier when red was red.


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