Bard EIFM-5 User manual

INSTALLATION INSTRUCTIONS
ECONOMIZERS WITH EXHAUST
MODEL
EIFM-5
For Use with Bard 3-1/2 through 5 Ton
Wall Mount Air Conditioners
and Heat Pumps
Manual : 2100-220G
Supersedes: 2100-220F
File: Volume III Tab 19
Date: 09-18-00
Bard Manufacturing Company
Bryan, Ohio 43506
Since 1914...Moving ahead, just
as planned. © Copyright 2000

Manufactured under U.S. patent number 5,301,744.
Other patents pending.
COPYRIGHT SEPTEMBER 2000
BARD MANUFACTURING COMPANY
BRYAN, OHIO USA 43506
CONTENTS
GENERAL
General Information ................................................. 1
Unpacking ................................................................ 1
Description ............................................................... 1
INSTALLATION
Basic Installation ..................................................... 2
Economizer – WA, WL & WH Series ..................... 7
FIGURES
Figure 1 ................................................................ 2
Figure 2 ................................................................ 3
Figure 2A ................................................................ 4
Figure 3 ................................................................ 5
Figure 4 ................................................................ 7
Figure 5 ................................................................ 8
Figure 6 ................................................................ 9
TABLES
Table 1 ................................................................ 1
Table 2 ................................................................ 6
Table 3 ................................................................ 9

Manual 2100-220
Page 1
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 thru 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
EIFM models not suitable for use with
hot gas bypass models.
LEDOM EHTHTIWESUROF STINUGNIWOLLOF
5-MFIE 124AW 184AW 106AW
124LW 184LW 106LW 124HW 184HW 106HW

Manual 2100-220
Page 2
INSTALLATION
BASIC INSTALLATION
1. Unpack the economizer assembly which includes
the integral economizer with attached electrical
harness, mixed air thermistor, miscellaneous
hardware and installation instructions.
WARNING
Open and lock unit disconnect switch before
installing this accessory to prevent injury or
death due to electrical shock or contact with
moving parts. Turn thermostat to off.
2. Remove and save the existing exterior blower
access and service access panels on the Bard wall
mount unit. (See Figure 1.)
3. Remove and save existing unit return air filter and
center screw in front grille. (See Figure 1.)
4. Remove and discard the exhaust cover plate.
(See Figure 1.)
5. Install economizer by inserting the economizer
into the unit to the far left side clearing the right
filter
FIGURE 1
MIS-425
SERVICE ACCESS PANEL
SCREW
EXHAUST COVER PLATE
THERMISTOR
LOCATION
BLOWER ACCESS PANEL

Manual 2100-220
Page 3
bracket. Once the economizer is fully inserted,
slide the economizer to the right until it is tight
against the back of the control panel. (See Figure
2.)
IMPORTANT: Position front lip of economizer
on top of front grille and condenser partition (See
Figure 2 inset.) This is important to ensure
proper drainage of any water entering damper
assembly.
LEFT HAND UNITS – Slide the economizer to
the left until it is tight against the back of the
corner panel.
6. Mount mixed air thermistor to blower partition
with screws provided. Bracket with sensor
installs on top of blower partition and screws are
installed from the underside. Route wires as
shown and secure with wire tie. Connect wires to
thermistor. (See Figure 2.)
7. Open unit control panel to gain access to unit low
voltage terminal block.
8. FOR LEFT HAND UNITS – Reroute
economizer wiring harness to the left side of the
economizer.
(See Figure 2A.)
9. Route electrical harness leads through the 7/8”
bushing in control panel (Figure 2) into low
voltage box.
FIGURE 2
MIS-423
SIDE SECTION
RIGHT SIDE OF ECONOMIZER
SERVICE DOOR
LIP OF ECONOMIZER IS TO BE
BETWEEN THE CONDENSER
GRILLE AND SERVICE DOOR
FRONT GRILLE
CONDENSER PARTITION
THERMISTOR WIRES
TOP VIEW OF
BLOWER PARTITION
THERMISTOR
PART #8602-043
THERMISTOR BRACKET
PART #113-264
INSTALL THERMISTOR TO
BLOWER PARTITION. ROUTE
WIRES FROM ECONOMIZER
BEHIND FILTER BRACKET FILL
& THROUGH WIRE TIE.
WIRE TIE TO SUCTION LINE
LOW VOLTAGE WIRES TO
TERMINAL STRIP
WHEN INSTALLING ECONOMIZER, POSITION SO THAT HOLE
IN FRONT LIP IS CENTERED OVER HOLE IN CONDENSER
GRILLE TO INSERT A SELF DRILLING SCREW
MIST ELIMINATOR

Manual 2100-220
Page 4
MIS-1356
FIGURE 2A

Manual 2100-220
Page 5
FIGURE 3
MIS-350

Manual 2100-220
Page 6
10. Connect leads with fork terminal to corresponding
points on terminal strip. Re.: C.Y.G. (See wiring
diagram.)
11. Wire nut leads with 5/8” stripped ends to Y1 and
Y2 leads from thermostat. See wiring diagram in
this manual.
NOTE: Wires referenced in note one on wiring diagram
are for special control application only and are
not normally used in conjunction with other
circuitry to open the damper regardless of
outside temperature and humidity. Consult
factory for details.
12. Close control panel cover
13. Reinstall the blower access panel at top of unit
and secure with sheet metal screws.
14. Replace filter and screws in front condenser
grille.
15. ECONOMIZER CHECK OUT
A. Remove mist eliminator (Figure 2). Locate the
minimum position potentiometer. (See
Figure 3.)
B. Energize the evaporator blower by switching
thermostat to the manual fan position with
heat/cool in the OFF position.
C. Cycle the minimum position potentiometer
(factory set for 0% fresh air) 0 to full open.
(See Figure 3.) Throughout checkout
procedure observe operation of damper to
insure there is free, unobstructed operation
through the entire angle of damper travel.
Then adjust the damper minimum open
position to meet local codes or application
requirements. See example below.
EXAMPLE:
1. Measure return air temperature (RAT)
(assume 75° F for example).
2. Measure outdoor air temperature (OAT)
(assume 60° F for example).
3. Calculate the mixed air temperature (MAT)
which will result from the desired
combination of OAT (10 percent) and RAT
(90 percent).
.1 OAT + .9 RAT = MAT
or substituting example values
.1(60° F) + .9 (75° F) = 73.75° F
4. Adjust the minimum position potentiometer
knob until proper mixed air temperature as
calculated above is reached. Care should
be taken to insure thermometer is sensing
air that is well mixed.
5. Mark correct setting on dial of minimum
position potentiometer for future reference.
D. Adjust the enthalpy control to position A, B,
C and D to achieve the maximum combination
of temperature and humidity acceptable for the
installation as per Table 2 below. The
suggested setting is between A & B 70° DB
@ 55 percent RH. It is further recommended
to always set the control at C or above.) (See
Figure 3.)
E. Switch the thermostat fan control to automatic
and position the heat/cool switch to cool.
Adjust the thermostat temperature to engage
the first stage of cooling only (Y). This will
cause the dampers to modulate to achieve
mixed air temperature of 55° provided outside
air enthalpy is sufficiently low. If enthalpy is
too high for economizing, low enthalpy can be
simulated by temporarily removing and
jumping leads on terminal 2 and 3 of enthalpy
control together. This will also cause the
economizer damper to modulate away from
minimum position. (Be sure to properly
reconnect leads at end of checkout
procedure).
F. Readjust temperature on the thermostat to
engage the second stage of cooling (Y2).
The damper motor should return to previously
set minimum position. Compressor motor
should start.
G. Switch thermostat to OFF fan and OFF heat/
cool positions to de-energize unit.
Economizer damper should return to full
closed (100 percent return air) position.
Checkout is complete.
16. Replace control access panel and mist eliminator.
17. Remove blank off plate or barometric fresh air
damper if installed on the service access panel.
Plug the four (4) holes used to mount the BOP or
BFAD with the plastic plugs supplied with the
economizer.
18. Replace service access panel.
19. Economizer is now ready for operation.
TABLE 2
laiD gnitteS %02 HR %05 HR %08 HR
yplahtnE lortnoC gnitteS
AF.ged87 )C.ged62( F.ged37 )C.ged32( F.ged86 )C.ged02(
BF.ged37 )C.ged32( F.ged86 )C.ged02( F.ged36 )C.ged71(
CF.ged86 )C.ged02( F.ged36 )C.ged71( F.ged95 )C.ged51(
DF.ged26 )C.ged71( F.ged85 )C.ged41( F.ged35 )C.ged21(

Manual 2100-220
Page 7
FIGURE 4
ECONOMIZER OPERATION
ECONOMIZER – WA, WL & WH SERIES
FEATURES
•
One piece construction – easy to install with no
mechanical linkage adjustment required.
•Exhaust air damper – built in with positive closed
position. Provides exhaust air capability to prevent
pressurization of tight buildings.
•Actuator motor – 24 volt, power open, spring
return with built in torque limiting switch.
•Proportioning type control – for maximum “Free
Cooling” economy and comfort with up to 100%
outside air.
•Enthalpy control to monitor outdoor temperature
and humidity – adjustable.
•Minimum position potentiometer – adjustable to
control minimum damper blade position.
•Mixed air sensor to monitor outdoor and return air
to automatically modulate damper position.
ECONOMIZER SEQUENCE OF OPERATION
Condition A – Cool Outdoors
First stage cooling closes and powers the economizer
dampers to economizer mode and the indoor blower
starts. Mixed Air Sensor senses a mixture of return
air and outdoor air and modulates the dampers
accordingly. Compressor operation is inhibited. (See
Figure 4.)
If second stage closes on the thermostat, the dampers
return to the closed or minimum position setting and
the compressor starts for mechanical cooling.
MIS-347

Manual 2100-220
Page 8
CONDITION B – WARM OUTDOORS
First stage cooling cycles the compressor and dampers
remain in mechanical cooling mode.
FIGURE 5
MECHANICAL COOLING OPERATION
MIS-348

Manual 2100-220
Page 9
FIGURE 6
ECONOMIZER OPERATION
FOR SINGLE COMPRESSOR UNIT
WALL THERMOSTATS
FOR HEAT PUMPS WITH ECONOMIZER
Thermostat Part 8403-027 (White Rodgers IF92-71)
Electronic Heat Pump Thermostat
2 Stage Cool / 3 Stage Heat
FOR AIR CONDITIONING WITH ECONOMIZER
Thermostat Part No. 8403-021 (Honeywell T874D1934)
Subbase part no. 8404-012 (Honeywell Q674A1001)
2 Stage Cool / 2 Stage Heat
TABLE 3
(1) Low ambient control is required with economizer
for low temperature compressor operation.
)1(
ledoMrezimonocE renoitidnoCriAcisaB pmuPtaeHro
5-MFIE 124LW/AW 184LW/AW 106LW/AW
124HW 184HW 106HW
MIS-1351

Manual 2100-220
Page 10

Manual 2100-220
Page 11