American Dream Ultra Performance Geothermal Copper Series, Инструкция по установке и обслуживанию

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Page 28 000744MAN-02 25 MAY 2009
Heating TXV Adjustment
If it is determined during the start up procedure that one or more of the heating TXV’s need to be adjusted, the following proce-
dure and record sheet should be used to ensure that adjustments are recorded and performed in a systematic way. TABLE 17
describes what each of the columns in the Heating TXV record sheet table represents.
The heating TXV’s are set to four turns in from all the way out at the factory. This should be sufficient for most installa-
tions, however it is sometimes necessary to make adjustments if the ground conditions vary or if the loop lengths vary. The procedure
below explains how to properly adjust the TXV’s so that the task can be completed in the minimum amount of time.

The goal is to obtain a superheat value of 8-14°F (4-8°C) on each evaporator loop. It is good practice to average out the last
few readings as the TXV’s tend to cycle, causing the superheat to vary.

Adjusting a TXV in (clockwise) increases the superheat of its evaporator loop. Adjusting a TXV out (counter-clockwise)
decreases the superheat of its evaporator loop.

Adjusting one TXV affects the remaining evaporator loops, adjustments must be small and done to only one TXV at a time.

Adjustments are done every other time interval (ie every 10 minutes). The next two intervals should be averaged together for
the next adjustment.

Always adjust the TXV that is the furthest out.
ADJUSTMENT PROCEDURE
1. Fill in the information section at the top of the adjustment record sheet. Circle
° F or ° C at the top right.
2. Record all data for the initial readings (elapsed time 0). Adjust the TXV for the loop that is the furthest out. Record the num-
ber of the TXV, how much it was adjusted in turns (ie 1/4, 1/2, 1), and in which direction it was adjusted. Record the new
position of the adjusted TXV in the appropriate P column of the next row. Record the remaining TXV positions in their indi-
vidual P columns in the next row.
3. At the next time interval, record the data in the current row. Verify that the superheat of the adjusted TXV has changed in the
desired direction. Do not adjust the TXV. Mark —- in the TXV #, Turns, and In/Out columns.
4. At the next time interval, record all data. Adjust the TXV that is the furthest out. Record the TXV #, Turns and In/Out values.
Record the new position of the adjusted TXV in the appropriate P column of the next row. Record the remaining TXV posi-
tions in their individual P columns in the next row.
5. Repeat Steps 2 and 3 until all superheat values are within
8-14°F (4-8°C) .
TABLE 17 - TXV Adjustment Record Column Descriptions
Colunm Description
Time Actual Actual time of the reading
Time EL Elapsed time since the first reading
Common S Suction pressure
Common ET Evaporating temperature (from suction gauge or P/T chart)
Common D Discharge pressure
Loop P Loop TXV position. (Number of turns in from all the way out)
Loop V Loop Vapour Line temperature
Loop S Loop Superheat (Vapour Line temperature - Evaporating temperature
TXV # The TXV that is being adjusted
Turns The number of turns the TXV is being adjusted
In/Out The direction the TXV is being adjusted (In=clockwise, OUT=counter-clockwise)