Engineering problem? Hmmmmm

[bernie]

Ive got a condensor that utilizes a discharge bypass valve(a-4-0\55),desuperheating tev(egs 1\6 L1), flood control(lac-4-215)and ranco fan cycling control set at 300psi.
This condensor has 2 fans, a 12# reciever and a suction accumulator.
Compressor superheat is at 70, at -5F box temp.
The discharge bypass line is locted and piped into the suction line in the condenser 2" ahead of the accumulator.
The desuperheating tev is located and piped in the suction line in the condensor about 10" ahead of the accumulator.
The sensing bulb for the desuperheating tev is located in between the DBV piping and desuperheating piping as they
enter into the suction line.
Condenser m#KH201L6HT3A-0790 (-30f SAT SUC TEMP @80FAMBIENT=
7670 BTUS PER HOUR.
EVAPORATOR M# KTW077ED-S2A-0566 (-20F EVAP TEMP @ 10F TD=
7650 BTUS PER HOUR, box design temp is -20F
EXPANSION VALVE (EGSE-1/2-ZP) IS INSTALLED.
SYMPTOMS ARE HIGH SUCTION SUPERHEAT AT COMPRESSOR.
WHATS GOING TO HAPPEN WHEN THE WEATHER TURNS WARM?
EVERYTHING IVE READ indicates I will not get the
proper mixing of the hotgas and liquid as it was piped from the factory. The sensing bulb is also located in the wrong place.
Why with a single evaporator would the even use this type of capacity control?
Ive been on the phone all week, trying to get an explanation from keeprite, Im getting lost in email

Had the box down to -15F and suction superheat at the
compressor was 57F
Looking at the data sheets for each piece of equipment,
and utilizing the expansion valve that they are. I
believe the tev is undersized for an oversized piece of equipment. Huh?
With a superheat that high at the compressor you would expect the box temp to be suffering but this is not the
case. It is my belief that the only time you can satisisfy your box requirements and still overheat your compressor is if the equipment is oversized.In this case the evap is oversized and the expansion valve is too small to flow the required liquid to maintain a reasonable suction superheat at compressor.
Am I making any sense of this, is my thought process flawed?
To top it all off the piping arrangment dosent match
any of sporlans guidelines or the manufactures own design drawing.
Anywho, I brought this to the attention of the keeprite engineering department, sent them a digital pic of the unit.
They in turn sent me a fax with the correct piping arrangement. told me to send a quote to repair. As soon as they got the quote I got an email stating that the piping would work just fine and all I had to do was change the location of the desuperheating tev bulb. What to do?
The darn guy backtracked on me, said he had numerous of these units on the west cost and they worked fine.

R-404a system
48-50F ambient
suction pressure 12-15 psi /suction temp at comp 42F
head pressure 225 psi /liquid line temp at outlet of reciever 92F
Box temp at time of reading -5F