I'm back, sorry about the delay. Here is some more data for your consideration. Let's start with the five ton unit.
Suction pressure at the compressor 40 PSIG Line temp 23.6 F
Discharge pressure at the compressor 170 PSIG Line temp 109.7 F
Earthloop liquid pressure 120 PSIG Line temp 59.8 F Vapor pressure 190 PSIG Line temp 119.2 F
Air coil Liquid 70 PSIG Line temp 48.3 F Vapor 40 PSIG Line temp 36.8 F
Amp draw 28.49 at 247.8 Volts
Air coil entering temps 68.3 db 57.4 wb
Air coil Leaving temps 49.2 db 45.6 wb
Line temps at the air coil 42.9 F liquid and 33.7 F vapor Line set length is 45'
Total BTUH delivered 4.5X 1875 (measured cfm at the airhandler) X 6.77 (enthalpy change) = 57,121.8 BTUH
Sensible BTUH 1.08 X 19.1(db delta T) X 1875 = 38,677.5
Latent BTUH = 20,444 All readings taken at steady state minimum 15 minutes of run time
Blower draw 6.92 Amps 115 Volts G E ECM Motor ! HP

To help keep things clear I will post each unit seperate. Here is the four ton unit.
Compressor pressure suction 60 PSIG line temp 47.4 F discharge 220 PSIG line temp 138.3 F
Earth loop Vapor pressure 250 PSIG line temp 130.2 F Liquid pressure 190 PSIG line temp 61.4 F
Air coil vapor pressure 55 PSIG line temp 48.3 F liquid pressure 98 PSIG line temp 83.9 F
Air coil temps entering 68.1 db 57.4 wb Leaving 51.3 db 47.8 wb
Air coil line temps vapor 46.5 F liquid 51.0 F (line set lenght=45')
Compressor amp draw 15.48 Blower amps 6.79 (G E ECM 1 HP)
Total BTUH= 42,993 Sensible= 30,845 Latent=12,148

Last but not least the two ton unit,
Compressor pressure suction 65 PSIG line temp 46.5 F discharge pressure 205 PSIG line temp 96.7 F
Earth loop liquid pressure 85 PSIG line temp 57.3 F vapor pressure 205 PSIG line temp 91.7 F
Air coil liquid pressure 75 PSIG line temp 56.4 F vapor pressure 65 PSIG line temp 51.5 F
Air coil entering temps 67.2 db 58.1 wb Air coil leaving 46.8 db 44.4 wb
Compressor amps 6.95 Blower amps .49 Both are 240 volt
I did not take air coil line temps because the line set is only 7' long.
I hope this answers every one's questions. Any thing else you want to know please ask, I am grateful for the constructive input.
Brian
Sorry forgot the BTU's
Total BTUH= 30,341 Sensible BTUH=18,948 Latent BTUH=11,394

Posted By airhead1164 on 08/31/2009 4:25 PM
... Amp draw 28.49 at 247.8 Volts
... Total BTUH delivered 4.5X 1875 (measured cfm at the airhandler) X 6.77 (enthalpy change) = 57,121.8 BTUH
... Latent BTUH = 20,444
... Blower draw 6.92 Amps 115 Volts G E ECM Motor ! HP

The numbers highlighted here certainly match up to what the owner is experiencing:

Comfort - no problem: cooling's being delivered (57 KBTU/hr, with plenty of Latent for RH removal)

Electricity consumption: wow!

7.1 KW to produce the 57 KBTU/hr capacity.  My WaterFurnace 5 ton unit produces two-thirds capacity in 1st stage for about 3.2 KW (including pumps - see http://welserver.com/cgi-bin/plot/WEL0043/InstantaneousPowerUsage.gif ), and is spec'd at 4.2 KW in 2nd stage (full 5 tons).

This DX unit is operating at almost one-half the efficiency of my WF 5 ton unit.

Even the ECM blower fan motor power draw is high.  At 1500 CFM mine draws 210 watts (1 amp at 230 volts).  The DX unit's ECM motor, at 1875 CFM, is drawing 720 watts.  Perhaps the ductwork is much more restrictive.

Best regards,

Bill 

Bill brings up a good question, how much return air do all the units have?

I agree that blower amps for 4 and 5 ton seem way high. Compressor amps for the 5 ton seem way way high.

The high blower amps supports questioning ductwork / return air. Airside drybulb delta Ts look OK, though.

Blower power returns to air as heat, a substantial amount in the case of the 4 and 5 ton machines (~4000-5000 btuh, except that I don't know PF)

5 ton compressor suction seems low, others OK

How is earth loop pressure 30 psi above compressor discharge pressure on the 4 ton (typo, perhaps?)

The two ton's numbers seem quite good, except I'm curious about large delta P between earthloop vapor pressure and earthloop liquid pressure

Pressures / temperatures suggest the 5 ton might be undercharged, except that compressor amps are crazy high. Could there be a restriction in its lines?

DISCLAIMER - as I mentioned before, I don't know DX beyond the theory of its operation

Just to be sure, the 5 ton's run capacitor's amp draw is:?

Also, I agree completely that the blower amps on the 4 and 5 seem VERY high.

The 5 ton compressor is running way too high of amps, too. What's the status of the filter/drier in the 5 ton's refrigerant lines?

As far as it being "undercharged", the few things that would cause that situation do not include undercharged. It would more likely be restricted air flow, restricted refrigerant flow, faulty compressor/run capacitor, or plugged/malfunctioning liquid flow control (assembly)...

This is a long thread...took a long time to read it all and catch up...maybe I should visit the site a little more often.

I'm surprised ESP wasn't measured for the units, noting the high ECM blower fan motor power draws.  It would quickly indicate possible ductwork restriction.  It doesn't require expensive instruments to measure, and it's not terribly time consuming.  And if separate static pressure measurements are made at the supply and return points, then further diagnosis may be possible on the return ducts alone.

I recommend the HVAC professional return to get ESP measurements.  Should help a lot to eliminate/confirm ductwork problem(s).  These measurements don't require the units to be in cooling or heating mode.

Can do the measurements in fan only mode, first getting the fan RPMs to match the fan's current draw to what was previously measured.  Then do ESP measurements.

Best regards,

Bill

Just to clear up somethings?

Those GE ECM motor are retrofits to the existing gas furnaces on the 4 and 5 ton?

 Duct design could have been designed at restrictive ESP.

The 2 ton is a factory variable speed air handler?  Installed separate from the original house?

Earthlinked systems are a split systems. As the air portion of the system, is not self contained in the unit, as most of the water source systems are.

Now there has been same concern about wrong capacitors installed on Copeland Compressor, as well. Causing higher then normal amp draws.

Oh yeah, Thanks for showing up again Clark.....it's been awhile


Edit
( Oops Bill, you beat me to the punch, I waited to long to hit the submit button))

I agree the ECM motors are working hard. The PSC motors I took out were begging for mercy. They were pulling max amps. I have modified the filter configuration and added what little I can for return air. The TESP is .75"wc for the four ton unit and .80"wc on the five ton. With the basement being finished with drywall I am hamstrung to do more right now. I will have to find my notes on the seperate static pressure readings. I noted TESP on the set I am working from right now. I still feel the elephant in the room is the high compressor amp draw. RE tuffluckdriller I am not sure what you mean on the capacitor amp draw.
Thanks,
Brian

If you assume 4.2 KW is spec for the compressor and associated electronics (simply looked up what a WaterFurnace Envision 5 ton spec is at 2nd stage, and assumed the DX technology performs at the same efficiency), then the unit is requiring 69% more power than it should be to produce the 57 KBTU/hr that was affirmed the unit is.

If you further assume that with better airflow the ECM should be drawing about 300 watts instead of 720, that's an excess of 420 watts.

Put the two specs together (4.2 + 0.3 KW), you get 4.5 KW total.

Comparing the 300 watts additional power for the ECM to operate with the high TESP, to the total 'spec,' it's only 7% of the problem.

Or, to agree with the above quote, the compressor's power draw is 93% of the total power draw problem.

This would say to focus on the compressor, refrigeration and earth heat exchange areas before anything else.

Maybe though, the "7% problem" is a tell-tale sign that a lot or most of the 57KBTU/hr cooling is not reaching rooms.  If this was the case, though, you would think the owner would be complaining of not being able to get rooms cool enough, and/or excessive run time.  I believe the owner has stated that getting rooms to tstat setting is not a problem.  But I haven't seen any measurement on run time (may be hard to do without a tstat that records it, or, some amount of instrumentation).

Still, you would think the compressor would just run longer, and not almost twice as hot as it should be, if air exchange was the primary problem.  Since the evap coil deltaT numbers don't look unusual, maybe there really is 'a big hole' somewhere, and it's in the ductwork.

Interesting.

Best regards,

Bill

Has anyone considered the fact that whatever" HOLE" exists presently has existed since my house was constructed four years ago? 

  If that was such an issue,how come my bills with  the so called inefficient gas furnace were a lot less to keep my house comfortable?


From reading previous threads, problems with Earthlinked Systems are not uncommon in combination with dismal customer service. 

Where now is the claim for 40% -60% savings over conventional systems, when all I have seen is 150% increase over the conventional system?

Yes the G E ECM motors are retrofitted to the existing furnaces. The two ton is a Nordyne variable speed air handler. The duct system is marginal at best, however the homeowner has several years of experiance running 13 seer AC on the existing duct system. So logic would dictate increasing the ac effiency should result in lower bills. Or am I missing something? The duct system and building envelope have actually been improved and yet the bills are out of sight. Thanks to everyone for your input,
Brian

I'm in strong agreement with Bill - focus on the lion's share of the problem.
However, there's clearly a restriction problem to have such a high pressure in the air handler/ductwork. I believe these are all interrelated and are complicating finding a solution.
If the air flow is restricted, then we would be getting an increased delta-T across the coil. Yes, ECM motors try to push the rated air through, but there's no guarantee that they actually are. What if they're working at their max capacity and still not moving enough air? If the delta-T's "looked normal, but the airflow was only, say, half what we think, then the BTUs delivered would also be half what we think, meaning the compressor situation is even worse than expected.
Also, if the air flow were that restricted, then you wouldn't be evaporating as much refrigerant as you should in the summer, throwing off pressures throughout the system.

Again, we need to isolate issues, one-by-one and rule them as definitely good or bad. Right now, we know that the duct system is "bad" at the air flow that the ECM systems are trying to push. How about flipping the switches on the ECM to reduce the CFM and see at what rated CFM you reach a reasonable pressure? You need to be working within the rated pressure range in order for the air handlers to actually move as much air as you think they are.

The CFM amounts I used were actual measurements. I traversed the return air duct. I agree the duct is not helping matters. That is why I am concetrating on the BTU delivery at the airhandlers. If we get the high energy consumption beat then I can address the delivery system. The ECM motors are actually rated for 1
1"wc TESP
Thanks,
Brian

I was recently asked to debug a 6 ton running with 1.4" ESP. The far upstairs zone just wasn't getting enough cooling - go figure!

0.75 - 0.80" is a bit high but not too bad.

That makes me wonder even more at the 6-7 amp blower power - still seems way way high for that ESP

I agree that the elephant in the room is the 5 ton compressor drawing 30 amps. Fix that and you've nailed much if not most of the problem.

How confident are you of the current reading instrument's accuracy?

I don't mean to question your competence or tools, but I recently found my own clamp meter to be a bit off.

What I mean by the amps of the capacitor is... when the compressor is running, what is the current measured on the wire from the run capacitor to the compressor? If it is 0 Amps, it's a bad capacitor...compressor still may run, but capacity and efficiency will be dramatically lower than normal. Also, current on the compressor will be high.

I'd assume Russ would have already checked that, though...

I did not check the amp draw there. I learned something new. Regarding my instruments there are dead on balls accurate. My tools go in for yearly calibration. I am also a certified air and water balancer.
Brian

I must correct myself...if it's a bad/weak capacitor, the compressor may still run, but efficiency will be dramatically lower than normal. Capacity should stay about the same. Current also will be high. I'm almost certain it's got a bad capacitor, based on your high current draw on the 5 ton, but obviously I'm just some internet guy located far away, and just offering up my little opinion...

I appreciate your opinion. I have checked the caps and have also changed them several times. Next wednesday we are going to change the four and five ton compressors. I hope this helps. Thanks to everyone for your input.
Brian