Discussion in 'Quotes and Proposals' started by Popoff, Apr 26, 2010.
I follow you. Just waiting for the WF response. If they make the cake, I'll eat it.
As one alternative plan, I'm considering leaving the wiring as is, and selecting both the compressor, and 10 kW (of the 15kW total) heat strips with the control circuit for the generator.
We can make due without aux. To ensure the generator doesn't get overloaded, I would disable aux through the DIP switch to make sure the heat strips can't engage with the compressor running.
The only potential flaw with this is - would the Envision packaged unit call for emergency heat in the event of a lockout? I was told once by a very helpful person with an English accent at WF that the Envision packaged unit (not the split) would automatically switch over to emergency heat without the need for the thermostat to be switched to Emergency Heat if a lockout occurred. I would like for WF to confirm if this would still be the case if the aux heat is disabled via the DIP switch.
Is it possible to switch the control power to be on the 5kW breaker as an option? It's on the 10kW breaker now.
Anothe solution that shouldn't get your installer in trouble would be an external control circuit.
We used to do them on boilers to avoid electrical permits......when changing an old steamer with pilot generator set-up to a 24v unit, instead of having an electrician pull a permit for a new boiler circuit and run the wires to it, we would simply plug a remote transformer in (wherever we could in the basement) and run thermostat wire to the boiler.
One could have an independant transformer (on a 110 circuit) for a geo as well. I would hesitate to run a third 220 circuit to the geo for the existing transformer simply because it would not be expected by a new technician and un expected means dangerous.
It is possible to do what you are looking for. We have emailed you the information to provide to your contractor.
Thanks Joe and WF.
WF, nothing received yet. I'll PM you my email address to make sure you have the correct address.
Would you please post the most up to date copy of the generator sizing sheet again. I may have an older copy. The Intellistart starting power listed for a ND064 is listed as 1.2 (maybe it should be 5.2?) Just looks like a typo based on other information on the page.
I attached a copy of what I have so you can see what I mean. I just want to make sure that I have the latest copy to give to my electrician.
Anyone - what am I doing wrong? I can't use Watts = Volts x Amps to tie into figures on this sheet (using the figures with or without Intellistart.) Looking at ND026 for example, Intellistart starting Amps is 18.2, and starting power (kW) is 2.4
18.2 amps x 240 volts = 4368 watts? I see the note regarding 1.25 safety factor, but I am still haven't been able to make this work out. I would really like to understand how this works.
Guess it's the 30% voltage dip combined with the 1.25 safety factor (maybe with a bit of rounding?)
Are voltage dips like this common on utility and generator power?
You are correct. We have spoke with our engineering staff and they have informed us that the starting power (kW) for the NDV064 with the IntelliStart® should be 5.2. They are taking the necessary steps to have this changed. At this time, the document you have attached is the most current Generator Sizing Sheet. We will post the new document, as soon as it has been corrected.
Please find the updated Generator Sizing Sheet attached.
Belated thanks for the explanation.
Is it safe to say, at least in layman's terms, that aux heat and emergency heat are the same thing but the term used varies with the circumstance of its' use?
For geothermal yes, the circumstance being whether the compressor is running or not.
It is my understanding that with an air source heat pump, the heat strips in the air handler engage to prevent cold air from blowing when the compressor is going through a defrost cycle. Not sure what this is called other it being part of the defrost cycle.
I'm still pondering aux and emergency heat use with a generator. I have some other thoughts that I'll post later.
As a possible option to avoid overloading a generator with electric heat (while other loads are present or may engage), some of Generac's transfer switches have a built in load shed module.
This module can (among other things) temporarily interrupt up to two 24 volt signals from a thermostat should the load be too great. I was thinking of passing the electric heat signal wire (Aux/E) from the thermostat through one of these connections, and then to the heat pump.
Sounds like a winner! (as long as the aux will instantly shut off)
Per the transfer switch manual:
"Generator overload condition is determined by generator frequency. Loads are shed when the frequency is <58Hz for 3 seconds or <50Hz for ½ Second (For 60Hz)."
Any overload we have will likely be between the generator full load capacity, and the breaker capacity on the generator itself, so I assume the load shedding will work as designed.
I'll manage loads and not solely rely on the load shed to avoid an inadvertent generator overload (where the generator breaker trips.) I'll include the water heater in the load shedding devise too.
I may turn off electric heat at the thermostats when we are home, and re-enable 10kW of heat on the first floor when we are on vacation in case of a lockout (and disable the aux lockout at the thermostat.) I will also turn off the water heater while we are away. The load shedding is just in case I forget to manage the load.
About a week ago in post # 50, welcoming other opinions, geome asked questions about generators. Here is my experience with my 15 K propane fueled Guardian.
It was installed turn-key for $5,200 in April 2003, way before the 3-ton geo came.
It has been maintained on a service contract for $250 per year, since install.
On average, it consumes about 180 gallons of propane each year. Its battery is charged by utility power. I don’t know the amount of electricity it consumes. The battery has been changed once at extra cost to the annual maintenance plan.
The rent on a 500-gallon propane tank is $48 per year.
It starts the geo (heat strips excluded), but lights dim for a moment. Water heater, stove, and clothes dryer are not connected to the generator.
It is noisy when one is outside standing near it. With all windows and doors to outside closed, we can hear it running from inside, but it is not bothersome. The noise is often indistinguishable from neighbor’s yard implements.
It has always worked during power outages.
The enclosure started to rust in about two years, as it is on the north side of the house, shaded, under trees, and generally moist.
Except for replacing the battery, and fixing the rust, no other repair has been needed so far.
Things I Will Do Differently:
I would buy aluminum enclosure to prevent early rusting.
I Would add Securestart (similar to Intllistart) on geo. I expect two benefits from it. First it will lower the dimming effect. Second it would free extra watts, and allow me to get rid of the emergency propane water heater, and connect the main hot water tank to the generator.
Awesome Masoud. Thank you for the information.
Can you tell me what is included in the service contract? I assume the basic items like oil change, oil filter, air filter, and battery check are included? How about diagnostic tests on generator output, etc.? I need to read up on various diagnostic tests that should be run, but if anyone has ideas on this, please tell us about it.
While we would probably only use our 3-ton (1st floor) unit during an outage, we asked our installer to install IntelliStart (on order) on our 3-ton and 2-ton (2nd floor) units. My reasoning is to not take a chance on overloading the generator should we not be home to turn off the 2-ton unit when an outage occurs.
We have a propane range and clothes dryer. I was very surprised when I looked up (out of curiosity) the current needed for an electric range. I also had no idea a steel enclosure could rust so quickly under those conditions.
Our generator should arrive tomorrow if all goes well with the delivery. Maybe 1-2 months to install. I'm trying to get my brother-in-law (electrician) to visit and install the electrical portion.
So, your generator runs about 60 to 90 hours in a typical year?
Our installer didn't foresee a problem using the load shedding to manage aux heat given our circumstances, so that's good.
P.S. Is that one visit per year on the service contract?
You are welcome. I’ll try to adequately answer your questions.
Technician makes 2 visits to the site, one in spring and one in fall.
Each time, pre-start checks include engine oil level, battery charger, battery and spark plug cables, and intake/exhaust vents.
Engine running checks include engine governor, warning lights, output voltage, frequency, electrical connections, transfer switch, and fluid leaks. Little adjustments are done at no extra charge.
During spring visit, synthetic oil, air and oil filters, and spark plugs are changed.
Priority emergency help (response time within 3 hours) is also offered, emergency visit charge applies.
Annual Run Time:
3 to 4 days without utility power each year is about right for my location.
Good Generator Forum:
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It is nice to be able to run both geo units on backup power.
If you don’t mind, geome, please share with us the cost of adding Intillistart.
Great information, including the web site!
Do you know what he checks for on the engine governor and the transfer switch?
I wonder if it would be a good idea to check the battery and crankcase heater (if you have them) current if the tech comes out when it is cold enough outside to engage these units?
So far, the installer told me that the IntelliStart unit cost (I assume this is my cost and not his cost) about $150 to $175 each. I'm guessing about 1 hour of time to install each, hopefully less. Since labor rates vary, posting install time may be more helpful than what I am charged for labor. I'll post more details on this when I have them.
Had I known about the factory IntelliStart option, I would have bought the units with it already installed (and possibly received a 30% tax credit on the incremental difference.)
I'll bring your soft start kit on the way to the turkey farm.
Need gas money$ plus the cashews you sent for Christmas. Christie says thanx.
BTW distributor and CM paid me end of FEB.
I have a limited understanding of the engine governor! I think output voltage and frequency are checked. If they both are over or both are under certain limits (both in one direction), a governor adjustment is indicated. Older generators, mine included, have mechanical governors. New machines generally come with electronic governors, perhaps they do not require adjustments.
The transfer switch is checked, simply, by turning off the utility power, using the main circuit breaker to the house. Then, it is good to see light.
The company that maintains my generator does not include battery and crankcase warmers on its maintenance checklist. If they are part of a system, their proper operation should be verified in the fall. Without them, I haven’t had any starting problems during winters. 5W-30 synthetic oil appears thin during cold weather, in Michigan.
Thank you for the info on Intellistart unit cost.
That is great! Good to get paid! Tell Christie she is welcome, for me.
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