Freezer - Refrigeration Appliance User Manual

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C06053
Fig. 56 -- EconoMi$e r IV Functional View
EconoMi$er IV
Table 11 provides a summary of Economizer IV.
Troubleshooting instruc tions are enclosed.
A functional view of the EconoMi$er is shown in 56.
Typical settings, sensor ranges, and jumper positions are
also shown. An EconoMi$er IV simulator program is
available from Carrier to help with EconoMi$er IV
training and troubleshooting.
EconoMi$e r IV Standard
Sensors
Outdoor Air Temperature (OAT) Sensor
The outdoor air temperature sensor (HH57AC074) is a 10
to 20 mA devi ce used to measure the out door-air
temperature. The outdoor-air temperature is used to
determine when the EconoMi$er IV can be used for free
cooling. The sensor is factory-installed on the
EconoMi$er IV in the outdoor airstream. (See Fig. 55.)
The operating range of temperature measurement is 40_ to
100_F(4_ to 38_C). See Fig. 55.
Supply Air Temperature (SAT) Sensor
The supply air temperature sensor is a 3 K thermistor
located at the inlet of the indoor fan. (See Fig. 57.) This
sensor is factory installed. The operating range of
temperature measurement is 0° to 158_F(--18_ to 70_C).
See Table 5 for sensor temperature/resistance values.
SUPPLY AIR
TEMPERATURE
SENSOR
MOUNTING
LOCATION
SUPPLY AIR
TEMPERATURE
SENSOR
C06033
Fig. 57 -- Supply Air Sensor Location
The temperature sensor looks like an eyelet terminal with
wires running to i t. The sensor is located in the “crimp
end” and is sealed from moisture.
Outdoor Air Lockout Sensor
The E conoMi$er IV is equipped with an ambient
temperature l ockout switch located in the outdoor
airstream which is used t o lock out the compressors below
a42_F(6_C) ambient temperature. (See Fig. 52.)
EconoMi$e r IV Control
Modes
IMPORTANT: The optional EconoMi$er2 does not include
a cont roller. The EconoMi$er2 is operated by a 4 to 20
mA signal from an existing field-supplied controller (such
as PremierLink™ control). See Fig. 54 for wiring
information.
Determine the EconoMi$er IV control mode before set up
of the control. Some modes of operation may require
different sensors. (See Table 12.) The EconoMi$er IV i s
supplied from the fac tory with a supply--air temperature
sensor and an outdoor-- air temperature sensor. This allows
for operation of the EconoMi$er IV with outdoor air dry
bulb changeover control. Additional accessories can be
added to allow for differe nt type s of changeover control
and opera tion of the EconoMi$er IV a nd unit.
Outdoor Dry Bulb Changeover
The standard controller is shipped from the factory
configure d for outdoor dry bulb changeover control. The
outdoor air and supply air temperat ure se nsors are
included as standard. For this control mode, the outdoor
temperature is compared to an adjustable setpoint se lected
on the control. If the outdoor-air temperature is above the
setpoint, the EconoMi$er IV will adjust the outside air
dampers to minimum position. If the outdoor-air
temperature is below the setpoint, the position of the
outside air dampers will be controlled t o provided free
cooling using outdoor air. When in this mode, the LED
next to the free cooling setpoint potentiometer will be on.
The changeover temperature setpoint is controlle d by the
free c ooling setpoint potentiomet er located on the control.
(See Fig. 58.) The scale on the potentiometer is A, B, C,
50TC