York YLAA0041 Installation Operation & Maintenance page 125

Form 150.72-ICOM6
Issue date: 12/19/2023
6. Set parameter 22-89 to the Sensorless Flow read-
out taken in the previous step.
7. Set parameter 22-87 to a value that is X% of the
value in 20-21. This percentage needs to be calcu-
lated based on the design flow and the published
minimum flow for the unit. This ensures that the
drive will not allow the pump to operate below the
minimum flow of the chiller. You have now read-
justed the quadratic control curve to match actual
site conditions.
8. Change parameter 0-20 back to default value of
option 1601 – "Reference [Unit]".
9. Change parameter 0-22 back to default value of
option 1610 – "Power [kW]".
10. Put the VFD back into AUTO mode.
Johnson Controls
LD18421
LD18422
LD18423
LD18424
Programming the drive
Instructions to access Service Mode are located on the
chiller control panel.
1. To enable Service Mode, set the unit rocker switch
to OFF.
2. Press the Program key.
3. Press the Up Arrow twice and then the Down Ar-
row twice.
4. Press the Enter/Advance key.
5. Press the Enter/Advance key until the Liquid Line
solenoid option is displayed.
6. Press the Up/Down arrow keys to enable the Liq-
uid Line solenoid output and press Enter/Advance
key.
7. Turn on the System 1 Fan Output 1. This sends
voltage to the drive, enabling you to adjust the
drive parameters.
8. Set up the drive. See Table 14 on page 126.
Setting up the ABB ACS255 VSD for the low
ambient kit
Refer to the ABB ACS255 manual for more detailed
instructions on entering modes and making adjust-
ments to the drive. Ensure that the drive is set for Par L
to see all parameter code settings.
Parameter structure
The parameters within the drive are split into two
groups. Group 1 is titled Short Parameter Mode and
is displayed as PAr S on the drive display. Group 2 is
titled Long Parameter Mode and is displayed as PAr L
on the drive display.
• PAr S group brings together the most commonly
used parameters to aid in a quick setup.
• PAr L group includes all of the drive parameters.
Section 6: Commissioning
6
125