York YCAL0019, Installation, Operation And Maintenance Manual

Page: 199 / 230

199
JOHNSON CONTROLS
SECTION 8 – UNIT OPERATION
FORM 150.67-NM1
ISSUE DATE: 4/28/2017
8
TB3
TB1
TB2
TO PANEL 10M TO FAN #2 (EXIS TING HARNESS) TO MICROBOARD (P7)
251 250 252 250A
251A 252A
WHT
BLK
TB3 TB1
TB2
TO PANEL 10M TO FAN #2 (EXIS TING HARNESS) TO MICROBOARD (P7)
251
250 252 250A
251A 252A
WHT
BLK
TB3
TB1
TB2
TO PANEL 7M 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 7M TO FAN #1 (EXIS TING HARNESS)
TO MICROBOARD (P4)
151 150 152 150A
151A 152A
WHT
BLK
FIGURE 58 - INVERTER WIRING
LD11302
TABLE 28 - YCAL0043-0066 VFD LOW AMBIENT OPTION – CONDENSER FAN CONTROL OPERATION
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