JOHNSON CONTROLS
138
FORM 150.66-NM2
ISSUE DATE: 09/25/2020
SECTION 8 - UNIT OPERATION
PROGRAMMING - YCAL 0025 - 0032
Condenser fan control type must be programmed under
both the OPTIONS and PROGRAM keys when a VFD
is installed on the chiller. Under the OPTIONS key, FAN
CONTROL must be programmed for DISCHARGE
PRESSURE CONTROL only. This will ensure the
condenser fan control is solely by discharge pressure
with no ambient control.
Under the PROGRAM key, the FAN CONTROL ON
PRESSURE should be programmed for 240 psig and
the FAN DIFFERENTIAL OFF PRESSURE should
be programmed for 80 psig.
Programming as suggested ensures the chiller control
points for the second fan in the fan staging sequence
and the inverter control points are matched for optimum
control of the fans at reduced ambient temperatures.
When the chiller and VFD fan control points are
programmed properly, the fans will operate as outlined
in Table 22.
FAN STAGE
ON
OFF
CONTACTOR
MICRO
BOARD
FAN #
1:
VFD Control
(1 fan
Variable Speed)
Fan Speed
Is A Function Of
Discharge
Pressure.
When The liquid
line Solenoid Is
Energized. Speed
Increases With
Pressure
FAN Will Turn Very
Slowly or Display
Only Slight Movement
When Pressure Drops
Below 160 psig. Fan
Will Turn Completely
Off When Liquid Line
Solenoid Deenergizes
7M
TB7-3
1
2:
1 Fan VFD
Control
2nd Fan
Full Speed
Under Contactor
Control
280 psig,
Both Fans
Will Be Running Full
Speed
Discharge
Pressure
< 200 psig (Pressure
Is
< Fan Control ON
Pressure of
280 psig Minus Fan
Differential
Pressure of 80 psig =
180 psig)
7M
&
8M
TB7-3
&
TB7-10
1
&
3
TABLE 22 – YCAL0025-0032 VFD LOW AMBIENT OPTION - CONDENSER FAN CONTROL OPERATION
TB3
TB1
TB2
TO PANEL 7M
TO FAN #1 (EXISTING HARNESS)
TO MICROBOARD (P4)
151
150
152
150A
151A
152A
WHT
BLK
TB3
TB1
TB2
TB3
TB1
TB2
TO PANEL 7M
TO FAN #1 (EXISTING HARNESS)
TO MICROBOARD (P4)
151
150
152
150A
151A
152A
WHT
BLK
lD11302a
FIG. 25 – INVERTER WIRING
J7
Summary of Contents for YCAL0012EC
Page 12: ...JOHNSON CONTROLS 12 FORM 150 66 NM2 ISSUE DATE 09 25 2020 THIS PAGE INTENTIONALLY LEFT BLANK...
Page 16: ...JOHNSON CONTROLS 16 FORM 150 66 NM2 ISSUE DATE 09 25 2020 THIS PAGE INTENTIONALLY LEFT BLANK...
Page 98: ...JOHNSON CONTROLS 98 FORM 150 66 NM2 ISSUE DATE 09 25 2020 THIS PAGE INTENTIONALLY LEFT BLANK...
Page 142: ...JOHNSON CONTROLS 142 FORM 150 66 NM2 ISSUE DATE 09 25 2020 THIS PAGE INTENTIONALLY LEFT BLANK...
Page 165: ...FORM 150 66 NM2 ISSUE DATE 09 25 2020 165 JOHNSON CONTROLS NOTES...