York YCAL0019, Installation Operation & Maintenance, Page: 174 / 200

JOHNSON CONTROLS
174
FORM 150.67-NM2 (209)
Unit Operation
TB3
TB1
TB2
TO PANEL 10 M TO FAN #2 (EXIS TING HARNESS) TO MICROBOARD (P7)
251 250 252 250A
251A 252A
WHT BLK
TB3
TB1
TB2
TO PANEL 10 M TO FAN #2 (EXIS TING HARNESS) TO MICROBOARD (P7)
251
250 252 250A
251A 252A
WHT BLK
TB3
TB1
TB2
TO PANEL 7 M TO FAN #1 (EXIS TING HARNESS)
TO MICROBOARD (P4)
151 150
152 150A
151A
152A
WHT
BLK
TB3
TB1
TB2
TB3
TB1
TB2
TO PANEL 7 M TO FAN #1 (EXIS TING HARNESS)
TO MICROBOARD (P4)
151 150
152 150A
151A
152A
WHT
BLK
FIG. 35 – INVERTER WIRING
LD11302
FAN STAGE ON OFF
CONTACTOR MICROBOARD FAN #
SYS 1 SYS 2 SYS 1 SYS 2 SYS 1 SYS 2
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
Off or Turn Very
Slowly When
Pressure Drops
Below 260 PSIG.
7M 10M TB7-3 TB10-9 1 2
2:
1 Fan VFD
Control
2nd Fan
Full Speed
Under Contactor
Control
425 PSIG,
Both Fans
Will Be Running
Full Speed
Discharge
Pressure
< 260 PSIG
(Pressure Is
< Fan Control
ON Pressure of
425 PSIG Minus
Fan Differential
Pressure of
125 PSIG = 300
PSIG)
7M
&
8M
10M
&
11M
TB7-3
and
TB7-10
TB10-9
and
TB10-10
1
&
3
2
&
4
TABLE 25 – YCAL0043-0066 VFD LOW AMBIENT OPTION – CONDENSER FAN CONTROL OPERATION