Manual 2100-449A
Page
3 of 13
GENERAL
GENERAL INFORMATION
The economizer should only be installed by a trained
heating and air conditioning technician. These
instructions serve as a guide to the technician installing
the economizer package. They are not intended as a
step by step procedure with which the mechanically
inclined owner can install the package.
The economizer housing is shipped in one carton which
contains the electrical harness, miscellaneous hardware
and installation instructions.
The economizer installation requires an additional two
stage cooling thermostat in place of the normal single
stage cooling thermostat. Also additional low voltage
wire will be required to transmit the second call (Y2)
for cool. (I.E. use 6 conductor thermostat wire for an
air conditioning unit and 9 conductor thermostat wire
for heat pumps.) See Page 12 for required thermostats.
If using a Bard master controller, the MC3000 Master
Controller is designed specifically to control two (2)
redundant Bard wall mount units equipped with
economizers.
Any wall mount unit equipped with an economizer
must also have a low ambient control installed. This
control can be factory installed or field installed. If
field installed, use kit CMA-6 (air conditioner models)
or CMH-7 (heat pump models).
UNPACKING
Upon receipt of the equipment be sure to compare the
model number found on the shipping label with the
accessory identification information on the ordering
and shipping document to verify that the correct
accessory has been shipped.
Inspect the carton housing of each economizer as it is
received, and before signing the freight bill, verify that
all items have been received and that there is no visible
damage. Note any shortages or damage on all copies of
the freight bill. The receiving party must contact the last
carrier immediately, preferably in writing, requesting
inspection by the carrier’s agent. Concealed damage not
discovered until after loading must be reported to the
carrier within 15 days of its receipt.
DESCRIPTION
The EIFM-3C economizer is designed to be used with
Bard 2-1/2 through 3 ton wall mount series air
conditioners and heat pumps with low ambient fan
cycling controls. They are electromechanical
economizer systems designed to provide “free” cooling
where the outdoor air temperature is cool enough to
provide the needed cooling without running the
compressor. When cooling is needed, the system
automatically takes advantage of the could outdoor air
when available and uses it for first stage cooling. This
then reduces the need to run the air conditioning
compressor providing lower operating costs and
increasing the service life of the equipment. If the
outdoor air gets too warm or humid to be helpful, the
enthalpy control detects the condition and automatically
closes the outdoor air and exhaust damper, opens the
return air damper and switches to the compressor
operation. This is all done automatically to achieve
maximum savings without attention for the user. See
Figure 6 & 7, Pages 10 & 11, for a block diagram of the
economizer operation logic flow. The unit is equipped
with a full modulating type damper motor which controls
the damper position to a factory set minimum supply air
temperature.
EIFM models not suitable for use with hot gas bypass
models.
TABLE 1
EIFM USED ON THIS MODEL
(1) Low ambient is required with Economizer for low pressure compressor operation.
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