26
Table 9 – Economizer Module - Right Hand Terminal
Blocks
Label Type Descr i ption
Top Ri ght Ter mi na l Bloc k
N/A The first terminal is not used
AUX2 I
24
VAC IN
Shut Down (SD) or Heat (W)
Conventional only
and
Heat Pump Changeover (O?B) in
Heat Pump mode
OCC 24
VAC IN
Occupied / Unoccupied Input
E- GND E- GND Earth Ground - System Required
EXH1 24
VAC OUT
Exhaust Fan 1 O utput
AUX1 O 24
VAC OUT
Programmabl e:
Exhaust fan 2 output
or
ERV
or
System alarm output
Bottom Right Terminal Block
Y2- 1 24
VAC IN
Y2 in - Cooling Stage 2 Input from
space thermostat
Y2- O 24
VAC OUT
Y2 out - Cooling Stage 2 Output to
stage 2 mechanical coolin g
Y1- I 24 VAC IN Y1 in - Cooling Stage 2 Input from
space thermostat
Y1- O 24
VAC OUT
Y1 out - Cooling Stage 2 Output to
stage 2 mechanical coolin g
C COM 24 VAC Common
R 24 V AC 24 VAC Power (Hot)
Ti me-out and Screen Saver
When no buttons have been pressed for ten minutes, the
LCD displays a screen save r, which cycles through the
status items. Each status item displays in turn and cycles
to the next item after five seconds.
HH79ZZ007 Dry Bulb Sensor
Economizers are shipped standard with an HH79ZZ007
outside air dry bulb sensor, which looks like an eye let
terminal with two green wires. This sensor is factory
installed on the front of the e conomizer in the outside a ir
stream. System default setting (high temp limit) is 63
°F,
and has a range of 48
°Fto80°F.
NOTE: A 2nd HH79ZZ007 se nsor is provided for mixed
(supply) air temperat ure.
NOTE: California high temperature setting requirements
by region are shown below.
GREEN
GREEN
20k Sensor
1/4 Terminal (2)
Fig. 32 - HH79ZZ007 Sensor
Table 10 – California Title 24 Regional High Limit Dry Bulb Temperature Settings
(Table 140.4- B Air Economizer High Limit Shut Off Control Requirements)
Device Type Climate Zones
Required High Limit (Economizer Off When):
Descriptions
Fixed Dry Bulb
1, 3, 5, 11- 16 Outdoor air temperature exceeds 75° F
2, 4, 10 Outside air temperature exceeds 73° F
6, 8, 9 Outside air temperature exceeds 71° F
7 Outside air temperature exceeds 69° F
Differential Dry Bulb
1, 3, 5, 11- 16 Outdoor air temperature exceeds return air temperature
2, 4, 10 Outdoor air temperature exceeds return air temperature minus 2° F
6, 8, 9 Outdoor air temperature exceeds return air temperature minus 4° F
7 Outdoor air temperature exceeds return air temperature minus 6° F
a Only the high limit control devices listed are allowed to be used and at the setpoints listed. Others such as Dew Point, Fixed Enthalpy, Electronic Enthalpy,
and Differen tial Enthalpy Controls, ma y not be used in any climate zone for compliance with Section 140.4(e) 1 unless a pproval for use is provided by the
Energy Commission Executive Director.
b At altitudes substantially different than sea level, the Fixed Enthalpy limit value shall be set to the enthalpy value at 75° F and 50% relative humidity. As an
example, at appr oximately 6,000 foot elevation , the fixed en th al py limit is approximately 30.7 Btu/lb.
40QQ
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