Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
PC 111
Catalog No. 534-80034
Printed in U.S.A.
Form 48/50HG-5SI
Pg 1
6-01
Replaces: New
Book 1
1
4
4
Tab
1a 1b 6a 6b
Installation Instructions
Part Number CRECOMZR009A00 and CRECOMZR011A00
GENERAL
The accessory Economizer package uses microprocessor-
based controls to sequence mechanical cooling with cool out-
door air (free cooling) to satisfy the cooling load and minimize
energy consumption. Free cooling can be used alone or in
conjunction with mechanical cooling.
The standard economizer uses an outdoor-air temperature
sensor to sense outdoor-air temperature. When the outdoor-air
temperature is between two configurable ambient temperatures,
the economizer is allowed to cool. These temperature configura-
tions are the Economizer High Temperature Lockout (ECL.H)
and the Economizer Low Temperature Lockout (ECL.L). The
economizer will provide cooling when the outdoor temperature
is suitable as defined above by the lockout settings and if either
a thermostat or a space temperature probe has signaled a cooling
demand. In addition, if an outdoor enthalpy sensor accessory
has been installed, then the enthalpy reading must also be “low”
before economizer cooling can occur.
When free cooling is available, the Economizer sequences
free cooling with up to three stages of mechanical cooling to
maintain comfort in the space. When free cooling is not avail-
able, the Economizer modulates to an adjustable minimum
position to maintain a supply of fresh air entering the building.
Optional barometric relief dampers provide natural building
pressurization control. An optional power exhaust system is
available for jobs requiring greater relief.
PACKAGE USAGE AND CONTENTS
SAFETY CONSIDERATIONS
Installation and servicing of air-conditioning equipment can
be hazardous due to system pressure and electrical compo-
nents. Only trained and qualified service personnel should
install, repair, or service air-conditioning equipment.
Untrained personnel can perform basic maintenance func-
tions of cleaning coils and filters and replacing filters. All other
operations should be performed by trained service personnel.
When working on air-conditioning equipment, observe precau-
tions in the literature, tags and labels attached to the unit, and
other safety precautions that may apply.
Follow all safety codes. Wear safety glasses and work
gloves. Use quenching cloth for unbrazing operations. Have
fire extinguishers available for all brazing operations
INSTALLATION
1. Remove two manual dampers and one mist eliminating
filter from the outdoor air hood in the return end of unit.
(See Fig. 1.) Save the screws to use later.
2. Remove the side panel on the return end of the unit to ex-
pose the return section of the unit. Save the screws for use
later when replacing the panel. The inside of the unit will
contain a frame for installing the economizer as shown in
Fig. 2.
3. Remove the frame support brackets from both sides of
the frame inside the unit. Save the screws for use later.
4. Uncrate the economizer assembly. Position the damper
assembly so that it will rest on the angle bracket support
at the bottom of the economizer frame inside the unit.
Slide the economizer into the unit. (See Fig. 3.) Secure
the damper assembly to the frame using the
1
/
4
-in. screws
provided.
5. Install one of the plastic bushings, supplied with the ac-
cessory, into the wire hole in the damper frame at the ac-
tuator side of the unit. (See Fig. 4.)
IMPORTANT: Read these instructions completely
before attempting to install the accessory Economizer.
48/50HG UNIT SIZE
PACKAGE NO.
QTY
CONTENTS
014-024
(CRECOMZR009A00)
50TG500288
1
Economizer Assembly
50TG400612
1
Wire Harness
50TG400620
1
Wire Harness
50TG500596
1
Control Board
50TG400517
1
Block-Off Panel
KH03DU350
3
Filters
—
1
Plastic Bushing
—
10
1
/
4
-14
5
/
8
-in. Screw
—
4
#14-10
7
/
8
-in. Washer Head
Screw
—
5
#6-20
3
/
4
-in. Pan Head Screw
—
4
8-in. Wire Tie
—
6
15-in. Wire Tie
028
(CRECOMZR011A00)
50TG5000720
1
Economizer Assembly
50TG4000612
1
Wire Harness
50TG4000620
1
Wire Harness
50TG5000596
1
Control Board
50TG4001186
1
Block-Off Panel
KH03DU350
3
Filters
—
1
Plastic Bushing
—
10
1
/
4
-14
5
/
8
-in. Screw
—
4
#14-10
7
/
8
-in. Washer Head
Screw
—
5
#6-20
3
/
4
-in. Pan Head Screw
—
4
8-in. Wire Tie
—
6
15-in. Wire Tie
IMPORTANT: Do not adjust the damper assembly.
the motor and damper have been pre-set and adjusted
for proper operation.
Turn off unit power and lock out. Electrical shock and per-
sonal injury could result.
Cover the duct opening as a precaution so objects cannot
fall into the return duct opening.
48/50HG014-028
Large Rooftop Units
Accessory Economizer Package
