Verifying Proper Air Flow (Cfm) (Cv, Igv's Or Vfd's); Exhaust Fan Operation - Trane Voyager RT-SVX17C-EN Installation Operation & Maintenance

Verifying Proper Fan Rotation
Using the Service Test guide in Figure 13, momentarily jump
across the test terminals one time for constant volume appli-
cations, or three consecutive times for a variable air volume
application, to start the Minimum Ventilation Test.
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 inadvertently
energized. Failure to disconnect power before servicing
could result in death or serious injury.
The Exhaust Fan will start anytime the economizer
damper position is equal to or greater than the exhaust
fan setpoint.
The economizer will drive to the minimum position setpoint,
exhaust fans may start at random, IGV's will be controlled by
discharge pressure (if applicable), and the supply fan will
start.
Once the supply fan has started, check for proper rotation.
The direction of rotation is indicated by an arrow on the fan
housing.
If the fan is rotating backwards, open the main power discon-
nect switch upstream of the unit terminal block or the unit
factory mounted disconnect switch.
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 inadvertently
energized. Failure to disconnect power before servicing
could result in death or serious injury.
Interchange any two of the field connected power wires at
the unit terminal block or factory mounted disconnect switch.
Note: Interchanging "Load" side power wires at the
supply fan contactor will only affect the Fan
Rotation. Ensure that the voltage phase sequence at
the main unit terminal block or the unit mounted
disconnect switch is ABC as outlined in the
"Electrical Phasing" section.
Verifying Proper Air Flow (CFM)
(CV, IGV's or VFD's)
1. All systems - Set the minimum position setting for the
o
economizer to 0 degrees using the setpoint potentiom-
eter located on the Economizer Actuator in the return
section with the supply fan "On" and rotating in the
proper direction:
CV applications - Measure the amperage at the supply
fan contactor and compare it with the full load amp
(FLA) rating stamped on the motor nameplate.
Unit Start-Up (Continued)
IGV's - With the O/A dampers fully closed, measure the
amperage at the supply fan contactor and compare it
with the full load amp (FLA) rating stamped on the motor
nameplate.
VFD's - With the O/A dampers fully closed, read the
amperage displayed on the VFD screen and compare it
to the motor nameplate.
Note: On VAV applications, IGV's will be under
control of the Discharge Static Pressure setpoint for
the first six minutes of this test mode. Verify that the
IGV's have been driven to the full open position or
the VFD output is at 60 Hz before measuring the fan
motor amps.
If the actual amperage exceeds the nameplate value, static
pressure is less than design and air flow is too high. If the
actual amperage is below the nameplate value, static pres-
sure is greater than design and air flow is too low.
2. To determine the actual CFM (within + 5%), plot the fan's
operating RPM and the Theoretical BHP onto the appro-
priate Fan Performance Curve in Figure 14.
Theoretical BHP Formula:
Actual Motor Amps
Motor Nameplate Amps
Where the two points intersect, read straight down to the
CFM line. Use Tables 17 through 20 to select a new fan
drive if the CFM is not within specifications.

Exhaust Fan Operation

To start the optional power exhaust fans, use the econo-
mizer test procedures in Figure 13 to drive the economizer
dampers to the open position. The exhaust fans will start
when the damper position is equal to or greater than the ex-
haust fan setpoint. If optional power exhaust is selected, an
access door must be field-installed on the horizontal return
ductwork to provide access to exhaust fan motors.
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 inadvertently
energized. Failure to disconnect power before servicing
could result in death or serious injury.
The Exhaust Fan will start anytime the economizer
damper position is equal to or greater than the exhaust
fan setpoint.
Verify that the fans are operating properly and the CFM is
within the job specifications. Refer to Table 21 for the ex-
haust fan performance characteristics.
If the fan speed needs to be changed from its current operat-
ing speed, refer to the unit wiring diagram and the XTB1 and
XTB2 terminal strip located in the economizer section.
40
X Motor HP = Theoretical BHP