York ZF078-150 - Supply Air Limitations; Honeywell Economizer Control W7212; Belt Adjustment

518674-YIM-C-0610
38 Johnson Controls Unitary Products
Figure 28: Honeywell Economizer Control W7212
Phasing
Predator
®
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 29.
Figure 29: 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.
Table 13: Supply Air Limitations
Unit Size (Ton) Minimum Maximum
078 (6.5) 1950 3250
090 (7.5) 2250 3750
102 (8.5) 2550 4250
120 (10) 3000 5000
150 (12.5) 3750 6250
A
A
A
B
SPAN LENGTH
DEFL. FORCE
C*
* NEVER LOOSEN