General Information, Unpacking, Description

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 9 for required thermostats.

If using a Bard master controller, the MC91AE 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 orders 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-5 economizer is designed to be used with Bard 3-1/2 through 5 ton wall mount series air conditioners and heat pumps equipped 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 cold 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 from the user. See Figure 6 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.

TABLE 1

(1)		FOR USE WITH
MODEL		FOLLOWING UNITS

	WA38		WL42	WH42

	WA42		WL48	WH48

	WA48		WL60	WH60

EIFM-5C	WA49		WL70	SH38

	WA60			SH43
	WA60			SH43

	WA61			SH49

	WA70			SH61

	WA72

(1)Low ambient control is required with economizer for low temperature compressor operation.

EIFM models not suitable for use with hot gas bypass models.

Manual 2100-447 Page 1

GENERAL