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1. Remove 9 screws holding each damper assembly in
place. See Fig. 37. Each damper assembly is secured with
3 screws on each side and 3 screws along the bottom.
Save screws.
2. Pivot each damper assembly outward until edges of
damper assembly rest against inside wall of unit.
3. Secure each damper assembly to unit with 6 screws
across top (3 screws provided) and bottom (3 screws
from Step 1) of damper.
4. With screws saved from Step 1, install brackets on each
side of damper assembly.
5. Remove tape from damper blades.
Step 9 — Route Static Pressure Sensors
VAV DUCT PRESSURE TRANSDUCER — The VAV duct
pressure transducer (VAV inverter pressure transducer) is locat-
ed behind the filter access door on the lower inner panel. See
Fig. 38. A section of field-supplied
1
/
4
-in. plastic tubing must
be run from the high pressure tap on the differential pressure
switch and connected to a field-supplied tap in the supply-air
duct. The tap is usually located
2
/
3
of the way out on the main
supply duct. Remove plug button in panel to route tubing.
BUILDING PRESSURE TRANSDUCER — The building
pressure transducer (modulating power exhaust pressure trans-
ducer) is located behind the filter access door on the lower
inner panel. See Fig. 38. A section of field-supplied
1
/
4
-in.
plastic tubing must be run from the high pressure tap on the
differential pressure switch to the conditioned space. The pres-
sure tube must be terminated in the conditioned space where a
constant pressure is required. This location is usually in an en-
trance lobby so that the building exterior doors will open and
close properly. Remove plug button in panel to route tubing.
The low pressure tap is factory-routed to the atmosphere.
For a positive-pressure building, route the high tap to building
air and low tap to atmosphere. For a negative-pressure
building, route the high tap to atmosphere and the low tap to
building air.
Step 10 — Install All Accessories —
After all the
factory-installed options have been adjusted, install all field-
installed accessories. Refer to the accessory installation instruc-
tions included with each accessory.
The 50A series units have a large number of factory-
installed options which were previously available only as
accessories. Some of the available options can also be installed
in the field if needed. In most cases the units have been
pre-wired so that the accessories can be easily installed.
Instructions are shipped with each accessory. Configuration of
the controls for these accessories as well as the factory-
installed options can be found in the Controls, Start-up, Opera-
tion, Service and Troubleshooting book. The following is a list
of some of the common accessories:
• Thermostats and Space Temperature Sensors
• Accessory Barometric Relief Damper
• Accessory Power Exhaust
• Non-Modulating to Modulating Power Exhaust
• Condenser Coil Hail Guards
• Motormaster® V Low Ambient Head Pressure Control
Be careful when tilting blower assembly. Hoods and blow-
ers are heavy and can cause injury if dropped.
AUXILIARY
CONTROL PANEL
PRESSURE TRANSDUCERS
(INSIDE OF PANEL)
LEGEND
VAV —
Variable Air Volume
Fig. 38 — Pressure Transducer Locations
(50AJ,AK,AW,AY060)
NOTES:
1. Unless otherwise specified, all dimensions are to outside of part.
2. Dimensions are in inches.
3. On 50AW,AY units, accessory barometric relief or power exhaust must be mounted in the field-supplied return ductwork.
Fig. 37 — Barometric Relief Damper and Power Exhaust Mounting Details
Summary of Contents for 48AJ/AK/AMD020
Page 3: ...3 Fig 1 Roof Curb 50AJ AK020 035 Units...
Page 4: ...4 Fig 2 Roof Curb 50AJ AK040 050 Units...
Page 5: ...5 Fig 3 Roof Curb 50AJ AK060 Units...
Page 6: ...6 Fig 4 Reduced Supply Duct Opening Roof Curb 50AJ AK060 Units...
Page 7: ...7 Fig 5 Base Unit Dimensions 50AJ AK020 035...
Page 8: ...8 Fig 6 Base Unit Dimensions 50AJ AK040 050...
Page 10: ...10 Fig 8 Base Unit Dimensions 50AW AY020 035...
Page 11: ...11 Fig 9 Base Unit Dimensions 50AW AY040 050...
Page 32: ...32 CONTROLS OPTION BOARD Fig 19 Small Chassis Component Location Size 020 035 Units...
Page 33: ...33 CONTROLS OPTION BOARD Fig 20 Large Chassis Component Locations Size 040 060 Units...
Page 34: ...34 Fig 21 Typical Main Control Box Wiring Schematic TO NEXT PAGE TO NEXT PAGE...
Page 35: ...35 FROM PREVIOUS PAGE FROM PREVIOUS PAGE Fig 21 Typical Main Control Box Wiring Schematic cont...
Page 36: ...36 TO NEXT PAGE TO NEXT PAGE Fig 22 Auxiliary Control Box Wiring Schematic...
Page 38: ...38 Fig 23 Typical Power Schematic Size 060 Unit Shown...
Page 39: ...39 Fig 23 Typical Power Schematic Size 060 Unit Shown cont...
Page 40: ...40 Fig 24 Controls Option Wiring Schematic...
Page 41: ...41 Fig 25 Electric Heat Control Circuit Size 060 Unit Shown...
Page 47: ......