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RT-SVX38B-EN
Unit Start-Up
Verifying Proper Air Flow
Units with Belt Drive Indoor Fan
Much of the systems performance and reliability is closely
associated with, and dependent upon having the proper
airflow supplied both to the space that is being
conditioned and across the evaporator coil.
The indoor fan speed is changed by opening or closing the
adjustable motor sheave.
Before starting the SERVICE TEST, set the minimum
position setpoint for the economizer to 0 percent using the
setpoint potentiometer located on the Economizer Control
(ECA), if applicable.
ReliaTel Control:
Using the Service Test Guide in
Table 6, p. 30
, momentarily jump across the Test 1 & Test
2 terminals on LTB1 one time to start the Minimum
Ventilation Test.
With the fan operating properly, determine the total
system airflow (CFM) by:
1.
Measuring the actual RPM,
2. Measure the amperage at the supply fan contactor and
compare it with the full load amp (FLA) rating stamped
on the motor nameplate.
a. Calculate the theoretical BHP using (Actual Motor
Amps/ Motor Nameplate Amps) X Motor HP.
b. Using the fan performance tables in the unit Service
Facts, plot the actual RPM (step 1) and the BHP (step
2a) to obtain the operating CFM.
3. If the required CFM is too low, (external static pressure
is high causing motor HP output to be below table
value),
a. Relieve supply and/or return duct static.
b. Change indoor fan speed and repeat steps 1 and 2.
•
To Increase Fan RPM; Loosen the pulley adjustment set
screw and turn sheave clockwise.
•
To Decrease Fan RPM; Loosen the pulley adjustment
set screw and turn sheave counterclockwise.
•
If the required CFM is too high, (external static
pressure is low causing motor HP output to be above
table value), change indoor fan speed and repeat steps
1 and 2.
•
To stop the SERVICE TEST, turn the main power
disconnect switch to the "Off" position or proceed to
the next component start-up procedure.
Economizer Start-Up
ReliaTel Control:
Using the Service Test Guide in
Table 6, p. 30
, momentarily jump across the Test 1 & Test
2 terminals on LTB1 one time to start the Minimum
Ventilation Test.
1.
Set the minimum position setpoint for the economizer
to the required percentage of minimum ventilation
using the setpoint potentiometer located on the
Economizer Control (ECA).
The economizer will drive to its minimum position
setpoint, exhaust fans (if applicable) may start at
random, and the supply fan will start when the
SERVICE TEST is initiated.
The Exhaust Fan will start anytime the economizer
damper position is equal to or greater than the exhaust
fan setpoint.
2. Verify that the dampers stroked to the minimum
position.
ReliaTel Control:
Momentarily jump across theTest 1 &Test 2 terminals
on LTB1 one additional time if continuing from
previous component start-up or until the desired start-
up component Test is started.
3. Verify that the dampers stroked to the full open
position.
4. To stop the SERVICE TEST, turn the main power
disconnect switch to the “Off” position or proceed to
the next component start-up procedure. Remove
electro mechanical test mode connections (if
applicable).
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
Rotating Components!
During installation, testing, servicing and
troubleshooting of this product it may be necessary to
measure the speed of rotating components. Have a
qualified or licensed service individual who has been
properly trained in handling exposed rotating
components, perform these tasks. Failure to follow all
safety precautions when exposed to rotating
components could result in death or serious injury.
