Trane TR200 - Page 200

20-3* Feedback Adv. Conversion
In air conditioning compressor applications it is often useful to control the system based on the temperature of
the refrigerant. However, it is generally more convenient to directly measure its pressure. This parameter group
allows the adjustable frequency drive’s PID controller to convert refrigerant pressure measurements into tem-
perature values.
20-30 Refrigerant
Option: Function:
Select the refrigerant used in the compressor application. This parameter
must be specified correctly for the pressure to temperature conversion
to be accurate. If the refrigerant used is not listed in choices [0] through
[6], select
User defined [7], use par.20-31 User-defined Refrigerant A1,
par.20-32
User-defined Refrigerant A2 and par.20-33 User-defined Re-
frigerant A3 to provide A1, A2 and A3 for the equation below:
Temperature =
A 2
(
ln
(
Pe +1
)
ì A 1
)
ì
A 3
[0] * R22
[1] R134a
[2] R404a
[3] R407c
[4] R410a
[5] R502
[6] R744
[7] User-defined
20-31 User-defined Refrigerant A1
Range: Function:
10.0000
N/A*
[8.0000 - 12.0000 N/A] Use this parameter to enter the value of coefficient A1 when par.
20-30
Refrigerant is set to User-defined [7].
20-32 User-defined Refrigerant A2
Range: Function:
-2250.00
N/A*
[-3000.00 - -1500.00 N/A] Use this parameter to enter the value of coefficient A2 when par.
20-30
Refrigerant is set to User-defined [7].
20-33 User-defined Refrigerant A3
Range: Function:
250.000
N/A*
[200.000 - 300.000 N/A] Use this parameter to enter the value of coefficient A3 when par.
20-30
Refrigerant is set to User-defined [7].
Parameter Description
TR200 Programming Guide 4-163