Ontario Electrical Usage for Waterfurnace Premier Seems Way Too High

Hey Mark!
I could use your locating skills.
I'm looking for a back up motor for my Trane 4 Ton GSUJ Fan. With the motor being one of the few moving parts, I'm figuring it will go out first, so having a back up would save money by preventing an Emergency visit from a local HVAC Company and pay $300 for a $75 motor. Throw in a few hundred since its a Geothermal Heat Source.

The motor label has the following information:
GE 5KCP39JG S595
208/230 vac
1/2 hp
1080 RPM
2.9 FLA

I might need to measure the motor and shaft length and go with a motor that's close, since GE may have stopped making the motor.
They're into making money by having money, running the GE Financing company.
Today everyone has a gig to make money off of US Citizens without much effort. My Cell Phone company is bringing in as much money each month as the Electric Company who gives me so much more for the dollar, when the grid isn't down due to a tree or beaver dam knocking out power.

Thanks Mark.

 

I don't know where this 30 F /ton number comes from - I see nothing like this in my unit's manual.

There is another table in my manual which I don't quite understand. It os under the heading "Unit Operating Pressures" and has a number of columns with units in PSIG (e.g., suction pressure, etc.). Also under the section identified as Heating - no desuperheater (and I ran my test with desuperheater off) there are a couple of columns titled Super-heat and sub-cooling, again no clue on this end what those mean. However, there are two columns that are titeld Water Temp Drop Deg. F DB and, Air Temp Rise. (What does DB stand for?)

Under the data listed for Entering Water Temp at 30 F, there are 3 flow rates. I will try to manually enter the the data which will hopefully come out looking readable

Water Flow____Water Temp Drop____Air Temp Rise
__GPM________Deg. F DB __________Deg. F
___1.5__________7.6 - 8.4___________14 - 20
___2.3__________4.8 - 5.6 __________16 - 22
___3.0__________3.4 - 4.2__________16 - 22

A note to the table indicates these values are based on 400 CFM per ton Air Flow and 70 F EAT Heating

My unit has 750 CFM airflow at Stage 1, and 1400 CFM airflow at Stage 2. Again, I don't know what this other table is supposed to be telling me.

As for the flow rates? I have 2 of those 26-116 pumps in my flow centre and both seem to be running. Loop fluid is not slushy from what I saw each time I removed the pressure gauge from the P/T ports. Lines are silent too so that does not suggest to me any air in the loop

 

Andrew,
You are looking at the Freon Side "Unit Operating Pressures" Tables. You don't deal in that area unless you own a Freon Recycling device and have passed the Freon Certification Test, Thanks for keeping us safe & protecting the Ozone Uncle Sam.

Degrees Subcooling, when dealing with water is how many degrees below phase change, Water to steam, or flashing to steam, given the pressure the water is at. The reason your vehicles antifreeze doesn't flash to steam is the design set point pressure relief of the cap keeping the contents at 15 lbs for instance. That's why you never remove the Radiator cap while the engine is hot, you'll get a face full of steam and scalding water as so many people have learned the hard way. Drop the pressure in the radiator and the water flashes to steam.

Degrees Superheat is how many degrees above the phase change temperature is the steam given the pressure in the environment/tank....

These terms are referring to the Freon in the Geothermal Freon side loop, which is the same concept only using water as the example.

DB - Dry Bulb air Temp Measurement, method the device uses to measure air temperature.
WB- Wet Bulb air Temp Measurement

My Operating Pressures Table includes Air Temperature Rise as the last item on the table . This is where you will find the expected Air Temperature Rise Band across your Unit. My Trane Table shows that for a typical 6 Ton Unit the Air Temperature Rise across the duct work of your Geothermal should be 21 to 27 degrees, given 35 degree Loop Inlet Water Temp, so you aren't far off, but on the low end at 21 degrees.

The table you included gives examples of Air Temperature Rise across your Unit for 30 degree Loop Temperature with a given loop flow rate per Ton. Notice as the Loop flow increases the Geothermal Air Temperature Rise increases to improve heating your home.

Your Unit would need 2400 scfm of air movement per those specifications. That's a lot of air.

My Closed Ground Loop appears to be free of air and quiet, but if you put your ear on the pipe at the 90 degree return near the ceiling as the water make the sharp turn, you can hear noises. Probably small air bubbles impinging on the elbow, and gas bubble collapsing due to the pressure increase in the elbow.

Make sure both Loop Grundfos pumps are in the same speed and listen for noise on one that is different than the other, could be some air binding, or wear on the impeller of one, so your flow is not meeting the required flow rate per ton. If one pump stopped pumping it could be hard to detect depending on how much of a pressure drop your Loop has inside. If the flow dropped too much the compressor would trip on one of it's lock out protective features. In Cooling mode the the compressor trips on high pressure on loss of loop heat sink. In heating mode its more than likely low pressure on the Freon side.

 

The table indicates that with an increase of water flow the temp drop (delta T) is reduced, and that the air temp raise (delta T) as in indicator of capacity is only influenced slightly, and only if your water flow is on very low end of the flow. Thus adding to the fact that running lesser water flow does not necessarily mean a significant drop in performance unless it affect the average water temperature in the coil significantly.

Keep in mind that the performance tables are measured with water, and that with methanol you must apply a correction factor since you pressure drop will be slightly off (not just the x485 instead of the x500 for the heat transfer capability).

Lets also step back a bit here. I cannot find a P070 model in the Waterfurnace literature, and the installation manual posted here by MrRXtech was incorrect, since it showed only single stage premier whereas the P066 was the largest one.
Water furnace made a dual stage Premier, but I only found a 4 and 5 ton install manual (attached).
Given the table you have posted here, and your model number, I do not question that WF made a P070 dual stage, but I just cannot find an installation manual online.

Your 7 psi in 1st versus 8 psi in 2nd stage does not much sense. The pressure drop through the heat exchanger does not change just because the compressor goes into 2nd stage. Your flow rate does not change. Nor does your EWT. PSI delta P means around 12.1 gpm according to the table you posted.

Check your measurements in steady stage.

DB means Dry Bulb, in heating it is meant to be at 70F DB of entering air temp per the rating standard.

The other issue wether your compressor amps include the blower already, and if the two loop pumps are wired through the unit, and the comp amps already includes their power usage. Also, the power for the pumps is not delivered to the space, while the comp watts and the fan watts are.
BTW, if you have (2) 26-116 pumps, you are using about 800 watts in pumping power. 26-116 are energy hogs and should not be used in geo systems.

 

You are misleading people again.
While the 12 gpm flow is on the low side for a 6 ton unit, it does not affect the heat extraction very much, and therefore does not significantly affect the delta T over the air coil, which WF recommends to be between 16-22 degrees F as indicated by the above table Andrew posted, not 30F, which would indicate not enough air flow over the coil.
If you measure a delta T of 20.5 and 21.2 over the air coil that is exactly the delta T WF recommends.

 

So Doc, are my COP's too low, did I calculate those correctly? I thought COP is supposed to be 3 or higher?

 

Ferguson for OEM. Refrigeration Sale for generic match.

 

You numbers don't fully add up. Getting good measurement s is tricky. Sure, heat pump COP is supposed to be 3 or higher. But your whole system is not reaching your specified numbers due the the high energy of inefficient 26-116 pumps. I would also check if both are running, since your flow is too low.

 

So when you say the numbers don't add up, is that because I did some of the math wrong, or because of the energy used by the pumps? (which BTW are the pumps that waterfurnace supplied as they are specified in the geoflow centre manual that I also have).

And how do I go about checking if both pumps are working? When we were up last weekend I had placed my hand on both units and felt vibration, but perhaps that is only vibration from one pump being picked up at the other since they are pretty close together?

And if only one pump is running, and that is contributing to the low flow, then I guess that would not mean that my system should not or could not be converted to a single 26-99 pump system such as those that you say you only install now? Or would an inoperative pump impede flows and cause the slowdown?

 

You loop might not be designed to have enough flow with a single 26-99. If indeed both 26-116 running in series, and you have only 12.1 gpm, your loop has a very high pressure drop and is very inefficient to pump through.
Yes, water furnace, as all the manufacturers, are not very evolved in designing efficient geo system. The build good heat pump though. See if either one of the pumps draws power. Or some supply shops have little magnets which rotate when the pump is running.
Yes, an inop pump is an additional flow restrictor, but not as much as one might think.
Have you considered the power factor in the calculations? The fact that your circulation pumps do not contribute to the BTUs delivered but use energy? Fan and compressor add to the capacity/ BTUs delivered. The differential in power usage between 1st and second stage is too high. Is the fan included in the compressor power? Where did you measure the power?

 

Thanks Mark. I'll take a look.

 

Andrew,
If you can borrow or rent a clamp on amp meter you could check the power to the two Grundfos pumps to see if they are both doing the same amount of work. I assumed your pumps were multi speed, like mine, since I haven't seen the photos for a while.

 

Hi. I missed this post. I have attached a scan of my Waterfurnace manual if you would like a copy of this for your own files. Also attached my Geolink manual for good measure. These are the only two that came with the cottage.

I take it then that what you are saying is that the pressure should not change at all regardless of stage. I had measured 33 psi leaving pressure on both stages and 40 and 41 psi on the entering pressures for the 2 stages. I have a semi-compressed disc or something like that in my lower back and the P/T ports are almost down at the floor level, so I am not all that bendable and may have misread the gauge due to looking at it on an angle. I'll pay closer attention next time. With respect to EWT, my impressions are that it gets lower over time while the system is running (based on my observations of my system). The coils are in the lake, but I bet the main supply and return lines between the house and the lake are very shallow, almost at ground surface because bedrock is so shallow. So maybe this is due to not enough coil in the lake, or cooling of the fluid between the house and the lake due to the shallow depth of the line and cold air temperatures?

The way my system is set up:

• Breaker Panel - 2 breakers:
  • 60A - labelled Furnace Compressor
  • 100A - labeled Furnace Elements. Furnace Blower Fan is also controlled by this breaker
• My lines between the furnace and the lake are black plastic(?) and are 1.75-inch outer diameter so I presume 1.5 inch I.D. Cannot speak to the coils on the lake bottom

• The two Grundfos Pumps look to be powered through the furnace. There is electrical cable to the pumps that originates from the furnace through a cutout located just above the bank of system fault lights and desuperheater switch. The electrical diagram on page 12 of my manual also suggests to me that these pumps are powered through the furnace - I think, but do not know for sure, it is on the furnace compressor circuit. And so what I take from this then is that I should subtract out those 800 Watts from my heating/COP calculations.

• The blower is on the Furnace Elements circuit. When running on stage 1, with flow at 750 cfm, it draws only 0.8A. At stage 2, the draw is about 3.7A. This must only be the blower as Aux. Heat is not on.
• Auxiliary Heat is provided by an EAL15 which has 3 stages (14.4 kW/49,100 BTU/hr) which each draws 20A (so 60A max), which confirms what I have seen before when monitoring current when testing Aux. Heat out

So:

• When I calculated my Electrical Demand I added up both the compressor amps and the blower amps and multiplied by voltage and a factor of 0.85 to get Watts.
• What I understand from you is that I need to remove the 800 Watts for the Grundfos pumps from the total. Should that be 800 Watts minused out or 800 Watts x 0.85? to get the right number?

 

Would it even be worthwhile to replace the two 26-116's with a pair of 26-99's at this stage in the life of the system (furnace system is 12-13 years old now) with electricity costs up here currently at $0.25/kWh?

I multiplied by 0.85 to get the total Watts, so is that what you mean by power factor?

As noted in my previous response, the blower fan is on a separate circuit. So in terms of the power differential between 1st and 2nd stage (28.3A - 16.3A = 12.0A) would it be correct to assume that the compressor in 2nd stage (24.0A) uses double the power of the compressor in 1st stage (12.0A). Which would then mean that 16.3A-12.0A = 4.3A is the power consumption of the 2 grundfos pumps plus other stuff consuming electricity in the furnace? (the pumps supposedly draw 1.75A each for a total of 3.5A, so there is an extra 0.7A to account for)

I measured amperage at the electrical panel, voltage on a pair of contacts inside the furnace

 

I have a clamp amp meter, but how would would I measure the current with this set-up? (see attached photo). You can see the BX Cable leading to the pump on the left from above, and the second short length of BX cable between the two pumps. I don't feel comfortable taking any of that apart to measure current.

 

Andrew,
Just read your post about how the Pumps are powered.
How about a stethoscope to listen closely to each pump at the motor area and inlet & outlet lines.

 

Andrew,
it is interesting that the literature does not seem to exist in the U.S., at least not on the water furnace website, or any other database, so I wonder if this is Canada specific. Also the manual for the flow center again shows a P066 as the largest heat pump.

No, usually 2nd stage is not twice the power draw. Usually 66%-75% is stage 1, and stage 2 is 100%. It seems that both your fan and pumping power is routed through your heat pump. The electricity running the blower is ending up as heat in the space, so that is like heating the space with a COP of 1. The pumping energy of the pumps end up in the loop. While they increase the EWT, they are only to be used in the denominator of the efficiency calculations.

Hive me a couple days and I will see what I can come up with in term of numbers.

 

Hi Doc.

Looking at my manuals, top of page 7 of the furnace manual says that Stage 1 runs at half the total tons. But you were saying that that would not use 1/2 the electricity, but more like 2/3, which my measured amperages are not showing. Did you ever get a chance to look at the numbers like you said you'd try to do?

Also Page 5 of the flow center manual says only one pump runs during stage 1, and both in stage 2 so I should expect more flow in stage 2, correct? But my measurements of pressure did not reslly show much improvement in flow between 1st and 2nd stage.

We are up at the cottage this week and I am going to get some more measurements tomorrow. Is it possible to measure current to the various components directly inside the furnace using a clamp meter? Rather than at the breaker panel which gives a total current for everything on the breaker - e.g., compressor, +1 or 2 grundfoss pumps, etc.

 

Andrew, no I did not have a chance to run those numbers. Sorry, but it is awfully busy since everybody is trying to get there system commissioned due to the tax credits sunsetting.
Again, you seem to have a unit not available in the U.S., or at least no documentation is available here. It could be that it is 50% in stage 1, although all the manufacturers now have a higher percentage in 1st stage, usually between 65-75%.

If indeed your pump comes on in stages, you should see more flow in 2nd stage. How much depends on the pressure drop of your whole system, it usually is around 30% more flow. Just some round numbers. It could be that only one is running all the time, or both are running all the time.

Be careful when you open the unit, 240 volts....

 

Andrew,
You have a Reciprocating Compressor that has 2 speeds.

From the numbers I saw in the past your 2nd stage loop pump isn't running in the 2nd stage.

I saw that your Unit does defeat the Desuperheater water heating system when Heat Stage 3 kicks in to energize the Heater Bank. The Compressor will continue to Run in Stage 2.

To find the Pump Block, follow the shielded cable from the Pump Flow Center back to the Geothermal Unit, Open the 220 power breaker to the Geothermal Unit and look inside for Pump Block 1. The center wire is the shared 120 lead, while the two outer wires supply the other 120 volt power to each pump. If wired per the drawing, the bolt that holds PB1 onto the sheet metal is located between the power leads for the Pump that runs in Stage 1. The other outside lead is for the Stage 2 Pump which is suspect as not operating. Check to see if there is slack wire on the inlet or outlet side of PB1 to get your amp meter sensor clamped around. Check the Stage 2 Pump first by hooking up the clamp on amp meter, then put the unit in service in Stage 2 after re-closing the 220 vac power breaker, by raising the thermostat set point to energize.