Danfoss VLT Series Programming Manual page 135

Parameter Description
20-23 Setpoint 3
Range:
0.000
ProcessCtrlUnit
3 3
3.18.3 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 meter group allows the
frequency converter's PID Controller to convert refrigerant
pressure measurements into temperature values.
20-30 Refrigerant
Option:
[0] R22
*
[1] R134a
[2] R404A
[3] R407C
[4] R410A
[5] R502
[6] R744
[7] User
defined
134
Function:
[-999999.999 - Setpoint 3 is used in Closed
999999.999 Loop Mode to enter a
*
ProcessCtrlUnit] setpoint reference that may
be used by the frequency
converter's PID Controller.
See the description of
20-20 Feedback Function.
NOTE
The setpoint reference
entered here is added to
any other references
that are enabled (see
meter group 3-1*).
Function:
Select the refrigerant used in the compressor
application. This meter 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]. Then, use 20-31 User
Defined Refrigerant A1, 20-32 User Defined
Refrigerant A2 and 20-33 User Defined Refrigerant
A3 to provide A1, A2 and A3 for the equation
below:
A 2
Temperature =
−
( ln ( Pe + 1 ) − A 1 )
MG.11.CC.02 - VLT
®
VLT HVAC Drive Programming Guide
20-31 User Defined Refrigerant A1
Range:
10.0000
20-32 User Defined Refrigerant A2
Range:
-2250.00
20-33 User Defined Refrigerant A3
Range:
250.000
20-34 Fan 1 Area [m2]
Range:
0.500
m2
*
20-35 Fan 1 Area [in2]
Range:
A 3
750
in2
*
®
is a registered Danfoss trademark
Function:
[8.0000 - Use this meter to enter the value of
*
12.0000 ] coefficient A1 when
20-30 Refrigerant is set to User
defined [7].
Function:
[-3000.00 - Use this meter to enter the value
*
-1500.00 ] of coefficient A2 when
20-30 Refrigerant is set to User
defined [7].
Function:
[200.000 - Use this meter to enter the value of
*
300.000 ] coefficient A3 when
20-30 Refrigerant is set to User
defined [7].
Function:
[0.000 - Used for setting the area of the air ducts in
10.000 connection with feedback conversion
m2]
pressure/velocity to flow. The unit (m
determined by the setting of 0-03 Regional
Settings. Fan 1 is used with feedback 1. In
case of flow difference control, set
20-20 Feedback Function to [1] Difference, if
flow fan 1 – flow fan 2 is to be controlled.
Function:
Used for setting the area of the air ducts in
connection with feedback conversion
pressure/velocity to flow. The unit (in
determined by the setting of 0-03 Regional
Settings. Fan 1 is used with feedback 1. In
case of flow difference control, set
20-20 Feedback Function to [1] Difference, if
flow fan 1 – flow fan 2 is to be controlled.
[0 -
15000 in2]
2
) is
2
) is