Carrier CRECOMZR001A02 Instructions and recipes

Cancels: IIK 548-36-17 IIK 548-36-26
9/15/95
Installation and Start-Up Instructions
Part Numbers CRECOMZR001A02 and CRECOMZR002A02
PACKAGE USAGE AND CONTENTS
UNIT PACKAGE
NO. CONTENTS
3to6
Tons CRECOMZR 001A02
1 — Barometric Relief Damper Hood
2 — Hood Sides
1 — Hood Top
1 — Outdoor-Air Inlet Screen
1 — Screen Retainer Cap
2 — Spacers
1 — Horizontal Block-Off Plate
30 —
5
⁄ 8 -in. no. 10 Screws
2—
3
⁄ 4 -in. no. 10 Screws
1 — Economizer with Control Board
Attached
1 — Outdoor-Air Thermostat (OAT)
1 — Knob
1 — Supply-Air Thermostat (SAT)
2 — Wirenuts
1 — Wire Tie
3 — Seal Strips
1 — Outdoor-Air Opening Panel
7
1
⁄ 2 to
12
1
⁄ 2 Tons CRECOMZR 002A02
1 — Barometric Relief Damper Hood
2 — Hood Sides
1 — Hood Top
2 — Outdoor-Air Inlet Screens
1 — Screen Retainer Cap
3 — Spacers
1 — Horizontal Block-Off Plate
1 — Vertical Discharge Block-Off
Plate
40 —
5
⁄ 8 -in. no. 10 Screws
3—
3
⁄ 4 -in. no. 10 Screws
1 — Economizer with Control Board
Attached
1 — Outdoor-Air Thermostat (OAT)
1 — Knob
1 — Supply-Air Thermostat (SAT)
2 — Wirenuts
1 — Wire Tie
1 — Screen Clasp
1 — Bottom Stop
3 — Seal Strips
1 — Outdoor-Air Opening Panel
GENERAL
Accessory economizer package utilizes cool outdoor air
to satisfy cooling load and minimize energy consumption.
Economizer cooling can be used alone or in conjunction with
mechanical cooling.
Astandard economizer uses a dry bulb thermostat to sense
outdoor-air temperature. For a more efficient system, an ac-
cessory solid-state enthalpy control can be substituted for
the dry bulb thermostat.
Also available as an economizer accessory is the differ-
ential enthalpy control. This system compares the tempera-
ture and humidity of outdoor air and return air and then ad-
justs the economizer position to ensure the lowest enthalpy
air is used for cooling.
IMPORTANT: Read these instructions completely
before attempting to install the accessory economizer.
INSTALLATION
Turn off unit power! Electrical shock and personal in-
jury could result.
1. Determine quantity of ventilation air required. Record
amount of air for use in Step 10.
2. Remove filter access panel by raising panel and swing-
ing panel outward. Panel is now disengaged from track
and can be removed. No tools are required to remove
filter access panel. Remove indoor coil access panel. Dis-
card panel and save screws. See Fig. 1.
3. Assemble outdoor-air hood top and side plates as shown
in Fig. 2. Install seal strips on hood top and sides. Put
aside screen retainer and screws for later assembly. Do
not attach hood to unit at this time.
4. On all 10 and 12
1
⁄ 2 ton units, install vertical discharge
block-off plate over duct openings. See Fig. 3.
5. Slide economizer into unit and secure with screws. See
Fig. 4.
6. If barometric pressure relief is required, remove the hold-
down screw from the barometric relief damper and mount
the barometric relief damper hood around the damper
with the 4 screws supplied. The longest part of the hood
should be above the top of the damper.
7. To install the economizer for a horizontal discharge
application:
a. Install the economizer so that the motor faces the
outdoor-air section and secure with screws. See
Fig. 5.
b. If barometric pressure relief is required, rotate baro-
metric relief damper 90 degrees so that it opens and
closes vertically. Mount the barometric damper hood
around the damper with the supplied screws. The long-
est part of the hood should be above the top of the
damper.
c. Install horizontal discharge block-off plate over open-
ing on the access panel. Block-off plate MUST be
installed before installing hood assembly. See Fig. 6.
NOTE: Install spacers at the same time as the hori-
zontal block-off plate using same screws. The spac-
ers are used to cover gaps between the economizer
assembly and the unit.
Small Rooftop Units
Gas Heating/Electric Cooling, Electric Cooling, and
Heat Pump Units
3to12
1
⁄ 2 Tons (50/60 Hz)
Accessory Economizer Package
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 111444
Tab 1a1b5a5a6a6b PC 111 Catalog No. 534-892 Printed in U.S.A. Form 48/50-39SI Pg 1 9-95 Replaces: 48/50-31SI

8. Plug the male plug of the unit economizer wiring har-
ness into the economizer control board. See Fig. 7.
9. As shown in Fig. 8, remove the indoor fan motor access
panel. Save all screws.
10. Determine damper position setting; see Fig. 9 or 10. Ad-
just damper setting by adjusting screws on the position
setting bracket. See Fig. 4 and 11. Slide position setting
bracket until the top screw is in the position determined
by Fig. 9 or 10. Tighten screws.
11. Install outdoor-air opening panel with screws from
Step 2.
12. Fasten hood top and side plate assembly and bottom stop
(on 7
1
⁄ 2 to 12
1
⁄ 2 ton units) to unit with screws
provided. See Fig. 2.
FILTER ACCESS PANEL
INDOOR COIL ACCESS PANEL
Fig.1—Typical Access Panel Locations
Fig. 2 — Outdoor-Air Hood Details
Fig.3—Vertical Block-Off Plate Installation
(10 and 12
1
⁄ 2 Ton Units Only)
Fig. 4 — Economizer Installation
Fig. 5 — Horizontal Discharge Economizer
Installation
2

13. Remove tape from outdoor-air thermostat (OAT). Fas-
ten OAT to inside of hood using screws and speed clips
provided. See Fig. 12. Make sure OAT terminals are up.
14. Place knob supplied with economizer on OAT. Set for
3 F below indoor room thermostat setting. If accessory
solid-state enthalpy control (EC) is used instead of the
OAT, see instructions shipped with EC for installation
and adjustment.
15. Connect OAT per Fig. 13.
16. Slide outdoor-air inlet screen(s) into screen track of hood
side plates. On 7
1
⁄ 2 to 12
1
⁄ 2 ton units, clamp screens to-
gether using clasp provided. While holding screen(s) in
place, fasten screen retainer to hood using screws
provided.
NOTE: Only 1 screen is provided with 3 to 6 ton units.
EXAMPLE: Given —
Negative Pressure ........................0.2in.wg
Outdoor Air .............................1100cfm
Determine —
Setting=6in.
Fig. 9 — Economizer Minimum Position Setting
(3 to 6 Ton Units)
EXAMPLE: Given —
Negative Pressure ........................0.1in.wg
Outdoor Air .............................1100cfm
Determine —
Setting=6in.
Fig. 10 — Economizer Minimum Position Setting
(7
1
⁄ 2 to 12
1
⁄ 2 Ton Units)
BLOCK-OFF PLATE
Fig. 6 — Horizontal Discharge Block-Off Plate
WIRING
HARNESS
U-SHAPED
HOLE
(NOT SHOWN)
Fig.7—Typical Economizer and Wiring Harness
WARNING
WARNING
Fig.8—Typical Access Panel Locations
(3 to 6 Ton, Standard Efficiency Unit Shown)
3

17. Mount supply-air thermostat (SAT) to the lower left por-
tion of the indoor blower housing with the screws pro-
vided (see Fig. 14). Attach the loose wires from the
economizer wiring harness to the thermostat as
follows:
a. Connect the violet wire to terminal T1.
b. Connect the pink wire to terminal T2.
c. Connect the white wire to the 24 vac terminal.
d. Connect the brown wire to terminal COM.
18. Replace indoor fan motor access panel using screws saved
in Step 9.
19. Replace filter access panel.
20. Turn on base unit power.
21. Barometric relief damper characteristics are shown in
Fig. 15 and 16.
43210
5
6
7
8
9
POSITION SETTING
BRACKET
TOP SCREW
Fig. 11 — Minimum Position Setting Bracket
MINIMUM
POSITION
OPEN
3
1
T
P
P1
T1
4
2
5
S
S
O
D
C
TR
B
REV. B
198818A
%
H
U
M
I
D
I
T
Y
90
70
60
30
10
DCBA
60 65 70
75
55
50 85
80
DAMPER
DAMPER
CLOSED
OPEN
OUTDOOR TEMP. °F
REV.
97-3672
CW–SETPOINTS–CCW
CONTACTSSHOWN IN HIGH ENTHALPY
RUSH AT 24VAC
3 mA MIN. AT 11 VDC
CONTACT RATINGS: 1.5A RUN, 3.5A IN
OR UNPOWERED STATE
1
2
3
TR
TR1
24VAC
ENTHALPY CONTROL
Fig. 12 — Outdoor-Air Thermostat/Enthalpy
Control Installation
4

START-UP
Operating Sequence
COOLING
3 to 6 Ton Units — When the outdoor-air temperature is above
the OAT setting and the room thermostat calls for cooling,
the compressor contactor is energized to start the compres-
sor and outdoor-fan motor. The indoor-fan motor (IFM) is
energized and the economizer damper moves to the mini-
mum position. After the thermostat is satisfied, the damper
moves to the fully closed position when indoor-fan motor is
deenergized.
When the outdoor-air temperature is below the OAT set-
ting and the thermostat calls for Y1 and G, the economizer
damper moves to the minimum position when the indoor fan
starts. The first stage of cooling is provided by the econo-
mizer. If the supply-air temperature is above 57 F, a switch
on the supply-air thermostat is closed between the T2 ter-
minal and the 24 vac terminal. This causes the damper to
continue to modulate open until the supply-air temperature
falls below 55 F or the damper reaches the fully open
position.
When the supply-air temperature is between 55 F and
52 F, the supply-air thermostat has open switches between
the T2 and 24 vac terminals and between the T1 and 24 vac
terminals. This causes the economizer damper to remain in
an intermediate open position.
If the supply-air temperature falls below 52 F, a switch on
the supply-air thermostat is closed between the T1 terminal
and the 24 vac terminal. This causes the damper to modulate
closed until the supply-air temperature rises above 55 F or
the damper reaches the minimum position.
When the supply-air temperature is between 55 F and
57 F, the supply-air thermostat has open switches between
the T2 and 24 vac terminals.This causes the economizer damper
to remain in an intermediate open position.
If the outdoor air alone cannot satisfy the cooling require-
ments of the conditioned space, economizer cooling is in-
tegrated with mechanical cooling, providing second stage
cooling. The compressor and outdoor fan will be energized
and the position of the economizer damper will be deter-
mined by the supply-air temperature.
When the second stage of cooling is satisfied, the com-
pressor and outdoor-fan motor will be deenergized. The damper
position will be determined by the supply-air temperature.
When the first stage of cooling is satisfied, and the IFM
is deenergized, the damper will move to fully closed
position.
Fig. 14 — Typical Economizer Supply-Air
Thermostat
Fig. 15 — Barometric Relief Damper
Characteristics—3to6TonUnits
Fig. 13 — Wiring Connections for Outdoor-Air
Thermostat
Fig. 16 — Barometric Relief Damper
Characteristics — 7
1
⁄ 2 to 12
1
⁄ 2 Ton Units
5

7
1
⁄ 2 to 12
1
⁄ 2 Ton Units — When the outdoor-air temperature
is above the OAT setting and the room thermostat calls for
cooling, the compressor contactor no. 1 is energized to start
compressor no. 1 and outdoor-fan motor. The indoor-fan mo-
tor (IFM) is energized and the economizer damper moves to
the minimum position. Upon a further call for cooling, com-
pressor contactor no. 2 will be energized, starting compres-
sor no. 2. After the thermostat is satisifed and the IFM is
deenergized, the damper moves to the fully closed position.
When the outdoor-air temperature is below the OAT setting
and the thermostat calls forY1 and G, the economizer damper
moves to the minimum position when the indoor fan starts.
The first stage of cooling is provided by the economizer. If
the supply-air temperature is above 57 F, a switch on the
supply-air thermostat is closed between the T2 terminal and
the 24 vac terminal. This causes the damper to continue to
modulate open until the supply-air temperature falls below
55 F or the damper reaches the fully open position.
When the supply-air temperature is between 55 F and
52 F, the supply-air thermostat has open switches between
the T2 and 24 vac terminals and between the T1 and 24 vac
terminals. This causes the economizer damper to remain in
an intermediate open position.
If the supply-air temperature falls below 52 F, a switch on
the supply-air thermostat is closed between the T1 terminal
and the 24 vac terminal. This causes the damper to modulate
closed until the supply-air temperature rises above 55 F or
the damper reaches the minimum position.
When the supply-air temperature is between 55 F and
57 F, the supply-air thermostat has open switches between
the T2 and 24 vac terminals.This causes the economizer damper
to remain in an intermediate open position.
If the outdoor air alone cannot satisfy the cooling require-
ments of the conditioned space, economizer cooling is in-
tegrated with mechanical cooling, providing second stage
cooling. Compressor no. 1 and outdoor fan will be ener-
gized, and the position of the economizer damper will be
determined by the supply-air temperature. Compressor no. 2
is locked out.
When the second stage of cooling is satisfied, the compres-
sor and outdoor-fan motor will be deenergized. The damper
position will be determined by the supply-air temperature.
When the first stage of cooling is satisfied, the damper will
move to fully closed position.
HEATING — When the room thermostat calls for heat, the
heating controls are energized as described in the base unit
Installation, Start-Up and Service Instructions. The indoor-
fan motor (IFM) is energized and the economizer damper
moves to the minimum position. When the thermostat is sat-
isfied, the damper moves to the fully closed position.
VENTILATION (CONTINUOUS FAN) — When the room
thermostat is set for continuous fan, the economizer damper
remains at minimum position for as long as the indoor fan
is energized.When the indoor fan cycles off, the damper moves
to the fully closed position.
6

TROUBLESHOOTING
PROBLEM CAUSE REMEDY
Damper does not
open. Indoor (evaporator) fan is off. 1. Check to ensure that 24 vac is present at terminal C1 on the IFC or that 24 vac is present at the IFO terminal. Check whether 24 vac is present at
PL6-1 (red wire) and/or PL6-3 (black wire). If 24 vac is not present, check
wiring (see unit label diagram).
2. Check proper thermostat connection to G on the connection board.
No power to economizer
motor. 1. Check that SW3 is properly making contact with the damper blade. Check that SW1 is in the NC (normally closed) position.
2. Check diode D18. If diode is not functioning properly, replace D18.
3. Confirm that the economizer control board is grounded properly at PL6-4
(brown wire) and at brown terminal of the economizer control board (brown
wire). The economizer motor must also be grounded properly at the negative
motor terminal (brown wire).
4. Verify SW1 and SW3 are working and wired properly (see unit label
diagram).
5. Check for 24 vac input at both PL6-1 (red wire) and PL6-3 (black wire). If
24 vac not present, check unit wiring (see unit label diagram). If 24 vac is
found in both places, check for 24 vac at the yellow terminal of the econo-
mizer control board (yellow wire). If 24 vac power is not present, replace
the economizer control board.
Economizer motor failure. If the indoor (evaporator) fan and economizer motor are energized, verify that
there is a minimum of 18 vdc at the positive motor terminal. If the motor is not
operating, replace the motor.
Economizer operation
limited to minimum
position.
OAT or EC set too high. 1. Set at correct temperature (3 F below indoor space temperature).
2. Check OAT or EC by setting above outdoor temperature or humidity level.
If the OAT or EC switches do not close, replace OAT or EC.
Economizer control board
incorrectly wired or not
functioning.
1. Perform the following tests when OAT or EC is closed, Y1 is called for, and
damper is at minimum position. Confirm 24 vac on gray terminal of the
economizer control board (gray wire). If 24 vac is not present, check wiring
(see unit label diagram).
2. Verify that SW1 and SW3 are wired correctly and working properly (see unit
label diagram).
3. Check to ensure that 24 vac exists at PL6-2 (blue wire). If 24 vac is not
present, check wiring (see unit wiring label diagram).
4. Check 24 vac output at PL6-10 (white wire). If 24 vac is not present, replace
economizer control board.
Incorrect SAT wiring or in-
operative SAT. 1. After verifying that the OAT and EC settings and the economizer control board wiring are correct, check to ensure that the 24 vac terminal of the SAT
has 24 vac (white wire). If OAT, EC, and control board are functioning and
wired properly and no 24 vac exists, check wiring (see unit label diagram).
2. If supply-air temperature is greater than 57 F, 24 vac should be found at ter-
minal T2 on the SAT (pink wire). If 24 vac is not present, replace SAT.
Damper does not
close. Incorrect economizer wiring. 1. Verify that SW2 and SW4 are wired and working properly (see unit label diagram).
2. Check diode D19. If diode is not functioning properly, replace D19.
Incorrect damper actuator
wiring or inoperative econo-
mizer circuit board.
1. After verifying that the wiring is correct, modulate the damper to the mini-
mum position. Remove the calls for G.
2. If the damper does not move, check for 24 vac at PL6-1 (red wire). If 24 vac
is not present, check wiring (see unit label diagram).
3. If damper still does not move, check for 24 vac at blue terminal of econo-
mizer control board (blue wire). If 24 vac is not present, replace the econo-
mizer circuit board.
Incorrect SAT wiring or in-
operative SAT. 1. After verifying that the wiring is correct and the economizer control board is functioning properly, place the OAT or EC switch in the closed position.
Place a call for Y1 and open the damper to the fully open position. Confirm
that the 24 vac terminal of the SAT has 24 vac (white wire). If 24 vac is not
present, check wiring (see unit label diagram).
2. If supply-air temperature is less than 52 F, 24 vac should be found at termi-
nal T1 on the SAT (violet wire). If 24 vac not found, replace SAT.
Economizer motor failure. If economizer control board and SAT are functioning properly, verify that there is
a minimum of 18 vdc at the positive motor terminal. If a minimum of 18 vdc is
present and the motor is still not operating, replace the motor.
Economizer damper
does not close on
power loss.
Insufficient battery power, in-
operative economizer control
board.
1. Check voltage potential across batteries. If lower than 14 vdc, replace close-
on-power-loss power supply (9-v alkaline batteries). Check this emergency
power supply on a regular basis or whenever the filters are changed.
2. If the close-on-power-loss and economizer control board are functioning
properly, check for 14 vdc or higher at the blue terminal of the economizer
control board (blue wire) when power is disconnected from unit. If 14 vdc is
not present, replace the control board.
LEGEND
C1 — Common Power
EC — Enthalpy Control
IFC — Indoor (Evaporator) Fan Contactor
IFO — Indoor (Evaporator) Fan On
OAT — Outdoor-Air Thermostat
PL — Plug
SAT — Supply-Air Thermostat
SW — Economizer Position Switch
7

Copyright 1995 Carrier Corporation
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 111444
Tab 1a1b5a5a6a6b PC 111 Catalog No. 534-892 Printed in U.S.A. Form 48/50-39SI Pg 8 9-95 Replaces: 48/50-31SI