Johnson Controls 20 J ZJ Series - Enthalpy Set Point Chart; Honeywell Economizer Control W7212

689670-BIM-A-0311
32 Johnson Controls Unitary Products
Figure 24: Enthalpy Set Point Chart
Figure 25: Honeywell Economizer Control W7212
Phasing
ZU 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.)
HIGH LIMIT CURVE W7212
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