1061903-XIM-A-0713
24 Johnson Controls Unitary Products
Figure 20: Honeywell Economizer Control W7212
Phasing
York
®
Model ZF units are properly phased at the factory. Check
for proper compressor rotation. If the blower or compressors
rotate in the wrong direction at start-up, the electrical
connection to the unit is misphased. Change the phasing of the
Field Line Connection at the factory or field supplied
disconnect to obtain proper rotation. (Scroll compressors
operate in only one direction. If the scroll is drawing low
amperage, has similar suction and discharge pressures, or
producing a high noise level, the scroll is misphased.)
Blower Rotation
Check for proper supply air blower rotation. If the blower is
rotating backwards, the line voltage at the unit point of power
connection is misphased (See ‘PHASING’).
Belt Tension
The tension on the belt should be adjusted as shown in Figure 21.
Figure 21: Belt Adjustment
N1
N
P1
P
EXH
Set
EXH
Min
Pos
IAQ
Max
IAQ
IAQ
Min
Free
Cool
T
T1
AQ1 AQ
SO+ SO
SR+
SR
A
BC
D
TR TR1
24
Vac
HOT
24
Vac
COM
EF EF1
2
3
4
5
1
+
Exhaust Air
Adjustment
Screw
Exhaust Air LED
Damper Min.
Position
Screw
Indoor Air Quality
Max. Adjustment
Screw
Indoor Air Quality
LED
Indoor Air Quality
Min. Adjustment
Screw
Free Cooling LED
Economizer Enthalpy
Set Point Adjustment
Screw
Scroll compressors require proper rotation to operate
correctly. Units are properly phased at the factory. Do
not change the internal wiring to make the blower
condenser fans, or compressor rotate correctly.
*Never Loosen
(A)
(C)*
(B)
Span Length
Defl Force
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