Unit Startup
11 6 RT-SVX24J-EN
HIGH VOLTAGE IS PRESENT AT TERMINAL BLOCK OR
UNIT DISCONNECT SWITCH.
3. Turn the 115 volt control circuit switch and the 24 volt
control circuit switch 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 appropriate Programming Manual for
VAV applications for the SERVICETEST screens and
programming instructions.
Use T
able 37, p. 110 to program the following
system
components for operation by scrolling through the
displays:
Supply Fan,
Variable Frequency Drive (100% Output, if applicable),
RTM Occ/Unocc Output (Unoccupied)
5. Once the configuration for the components is
complete,
press the NEXT k
ey 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 theTEST START key
is pressed and the delay designated in this step has
elapsed. Press the ENTER key to confirm this choice.
6. Press theTEST START key to start the test. Remember
that the delay designated in step 6 must elapse before
the fan will begin to operate.
7. With the VFD at 100% and the supply fan operating at
full airflow capability, measure
the amperage at the
supply fan contactors. If the amperage exceeds the
motor nameplate value, the static pressure is less than
design and the airflow is too high. If the amperage is
below the motor nameplate value, static pressure may
be too high and CFM may be too low.To determine the
actual CFM (± 5%);
a. Measure the actual fan RPM
b.
Calculate theTheoretical BHP
Actual
Motor Amps X Motor HP
Motor Nameplate Amps
c. Plot this data onto the appropriate Fan Performance
Curve beginning with Figure 62, p. 98. Where the
two points intersect, read straight down to the CFM
line.
Use this data to assist in calculating a new fan drive if the
CFM is not at design specifications.
An alternate method with less accuracy is to measure the
static pressure drop across the evaporator coil.This can be
accomplished by:
a. drilling a small hole through the unit casing on each
side of the coil.
Note: Coil damage can occur if care is not taken when
drilling holes in this area.
b. Measure the difference between the pressures at
both locations.
c. Plot this value onto the appropriate pressure drop
curve beginning with Figure 71, p. 118. Use the data
in Table 40, p. 125 (Component Static Pressure
Drops) to assist in calculating a new fan drive if the
CFM is not at design specifications.
d. Plug the holes after the proper CFM has been
established. Press the STOP key at the Human
Interface Module in the unit control panel to stop
the fan operation.
8. Press the STOP key at the Human Interface Module
in the unit control panel
to stop the fan operation.
Exhaust Airflow Measurement (Optional)
1. Close the disconnect switch or circuit protector
switch that provides the supply power to the unit's
terminal block or the unit mounted disconnect
switch.
HIGH VOLTAGE IS PRESENT AT TERMINAL BLOCK OR
UNIT DISCONNECT SWITCH.
2. Turn the 115 volt control circuit switch and the 24 volt
control circuit switch to the “On” position.
3. Open the Human Interface access door, located in
the unit control panel, and
press the SERVICE MODE
WARNING
Hazardous Voltage!
Disconnect all electric power, including remote
disconnects 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.
WARNING
Live Electrical Components!
During installation, testing, servicing and
troubleshooting of this product, it may be necessary to
work with live electrical components. Have a qualified
licensed electrician or other individual who has been
properly trained in handling live electrical components
perform these tasks. Failure to follow all electrical
safety precautions when exposed to live electrical
components could result in death or serious injury.
WARNING
Hazardous Voltage!
Disconnect all electric power, including remote
disconnects 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.
To Next Page
Loading...
