Unit Startup
RT-SVX24J-EN
115
System Airflow Measurements
Constant Volume Systems
1.
Ensure that the “System” selection switch at the
remote panel is in the “Off” position and the “Fan”
selection switch for constant volume units is in the
“Auto” position.
2. Close the disconnect switch or circuit protector switch
that provides the supply power to the unit terminal
block or the unit mounted disconnect switch.
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 CV
applications for the SERVICE TEST screens and
programming instructions.
5. Use
Table 37, p. 110
to program the Supply Fan for
operation by scrolling through the displays.
6. Once the configuration for the Fan 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 theTEST START key is pressed
and the delay
designated in this step has elapsed. Press the ENTER
key to confirm this choice.
7.
Press theTEST START key to start the test. Remember
that the delay designated in step 6 must elapse before
the fans will begin to operate.
8. With the system in the SERVICE MODE and the supply
fan rotating in the proper direction, 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 the Theoretical 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.
9. Press the STOP key at the Human Interface Module in
the unit control panel to stop the fan operation.
Variable Air Volume Systems
1.
Ensure that the “System” selection switch at the
remote panel is in the “Off” position.
2. Close the disconnect switch or circuit protector switch
that provides the supply power to the unit terminal
block or the unit mounted disconnect switch.
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.
Содержание SEHJ090-162
Страница 40: ...Dimensional Data 40 RT SVX24J EN Figure 13 Evaporative condenser water connection locations RIGHT SIDE VIEW ...
Страница 48: ...Installation 48 RT SVX24J EN Figure 18 Ductwork conversion ...
Страница 58: ...Installation 58 RT SVX24J EN Figure 36 5 Connected tubes 6 install panels Connected tubes 5 6 ...
Страница 75: ...Installation RT SVX24J EN 75 Figure 51 Hot water coil piping Figure 52 Steam coil piping ...
Страница 87: ...Installation RT SVX24J EN 87 Figure 57 Typical field wiring diagram for 90 to 162 ton CV control options ...
Страница 89: ...Installation RT SVX24J EN 89 Figure 59 Typical field wiring diagram for 90 to 162 ton VAV control options ...