Figure 56 - Inverter Power Wiring Sc; Figure 57 - Potentiometer Settings; Programming - York YCAL0019 Installation, Operation And Maintenance Manual

SECTION 8 – UNIT OPERATION
quirements are needed to run the VFD. Figure's 56 and
57 show the power and control wiring schematically
as well as the actual connections. The VFD controlled
fan will operate whenever the liquid line solenoid on
the respective system is energized.

PROGRAMMING

Condenser fan control type must be programmed un-
der both the OPTIONS and PROGRAM keys when a
VFD is installed on the chiller. Under the OPTIONS
key, FAN CONTROL must be programmed for DIS-
CHARGE PRESSURE CONTROL only. This will as-
sure condenser fan control of the chiller is solely by
discharge pressure, with no ambient control.
Under the PROGRAM key, the FAN
CONTROL ON PRESSURE should
be programmed for 425 PSIG and the
FAN DIFFERENTIAL OFF PRES-
SURE must be programmed for 125
PSIG.
Programming as suggested assures the chiller control
points for the second fan in the fan staging sequence
and the inverter control points are matched for opti-

FIGURE 56 - INVERTER POWER WIRING SC

198
7M
150A L1
151A L2
SPEED
CONTR.
152A L3
10M
250A L1
251A L2
SPEED
CONTR.
252A L3
mum control of the fans at reduced ambient tempera-
tures. When the chiller and VFD fan control points are
programmed properly, the fans will operate as outlined
in Table 28.
POTENTIOMETER SETTINGS
P1
292 PSI
P1 P1

FIGURE 57 - POTENTIOMETER SETTINGS

T1 150
T2 151
T3 152
T1 250
T2 251
CONDENSER
T3 252
FORM 150.67-NM1
ISSUE DATE: 4/28/2017
P2
32 PSI
P2 P2
CONDENSER
FAN NO. 1
FAN NO. 2
LD11301
JOHNSON CONTROLS
LD11300a