Trane INTELLIPAK ™ ™ ™ ™ ™ Commercial Single-Zone Rooftop Air Conditioners with CV or VAV Control - Manual (Page 82)

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Unit Start-Up (Continued)
Economizer Damper Adjustment
Exhaust Air Dampers
Verify that the exhaust dampers (if equipped) close tightly
when the unit is off. Adjust the damper linkage as necessary
to ensure proper closure. An access panel is provided un-
der each damper assembly.
Fresh Air & Return Air Damper Operation
The fresh air and return air damper linkage is accessible
from the filter section of the unit. The damper linkage con-
necting the fresh air dampers to the return air dampers is
preset from the factory in the number 1 position. Refer to
Table 4-5 for the appropriate linkage position for the unit
and operating airflow (CFM).
WARNING
No Step Surface!
Do not walk on the sheet metal drain pan. Walking on
the drain pan could cause the supporting metal to col-
lapse. Failure of the drain pan could result in death or
serious injury.
Note: Bridging between the unit's main supports
may consist of multiple 2 by 12 boards or sheet
metal grating.
Arbitrarily adjusting the fresh air dampers to open fully
when the return air dampers are closed or; failing to main-
tain the return air pressure drop with the fresh air dampers
when the return air dampers are closed, can overload the
supply fan motor and cause building pressurization control
problems due to improper CFM being delivered to the
space.
The fresh air/return air damper linkage is connected to a
crank arm with a series of holes that allows the installer or
operator to modify the amount of fresh air damper travel in
order to match the return static pressure. Refer to
Table 4-5 for the equivalent return air duct losses that corre-
spond to each of the holes illustrated in Figure 4-5.
To Adjust the Fresh Air Damper Travel:
1. Drill a 1/4" hole through the unit casing up stream of the
return air dampers. Use a location that will produce an
accurate reading with the least amount of turbulence.
Several locations may be necessary, and average the
reading.
WARNING
Hazardous Voltage!
Disconnect all electric power, including remote discon-
nects before servicing. Follow proper lockout/tagout
procedures to ensure the power can not be inadvert-
ently energized. Failure to disconnect power before ser-
vicing could result in death or serious injury.
HIGH VOLTAGE IS PRESENT AT TERMINAL BLOCK
1TB1 OR UNIT DISCONNECT SWITCH 1S14.
2. Close the disconnect switch or circuit protector switch
that provides the supply power to the unit's terminal
block 1TB1 or the unit mounted disconnect switch 1S14.
3. Turn the 115 volt control circuit switch 1S1 and the 24
volt control circuit switch 1S70 to the "On" position.
4. Open the Human Interface access door, located in the unit
control panel, and press the SERVICE MODE key to
display the first service screen. Refer to the latest edition
of the applicable SAHF-PTG manual for CV or VAV
applications for the SERVICE TEST screens and
programming instructions.
5. Use Table 4-1 to program the following system
components for operation by scrolling through the
displays;
Supply Fan (On)
Inlet Guide Vanes (100% Open, if applicable)
Variable Frequency Drive (100% Output, if applicable)
RTM Occ/Unocc Output (Unoccupied)
Fresh Air Dampers (Closed)
6. Once the configuration for the components is complete,
press the NEXT key until the LCD displays the “Start test
in __Sec.” screen. Press the + key to designate the delay
before the test is to start. This service test will begin after
the TEST START key is pressed and the delay desig-
nated in this step has elapsed. Press the ENTER key to
confirm this choice.
WARNING
Rotating Components!
Disconnect all electric power, including remote discon-
nects before servicing. Follow proper lockout/tagout
procedures to ensure the power can not be inadvert-
ently energized. Failure to disconnect power before ser-
vicing could result in death or serious injury.
7. Press the TEST START key to start the test. Remember
that the delay designated in step 6 must elapse before
the fan will begin to operate.
8. With the fresh air dampers fully closed and the supply fan
operating at 100% airflow requirements, measure the
return static pressure at the location determined in
step 1.
9. Press the STOP key at the Human Interface Module in
the unit control panel to stop the fan operation.
10. Open the field supplied main power disconnect switch
upstream of the rooftop unit. Lock the disconnect switch
in the "Open" position while working on the dampers.
11. Compare the static pressure reading to the static pres-
sure ranges and linkage positions in Table 4-5 for the
unit size and operating CFM.