Reliatel Control; Return Air Smoke Detector - Trane TC*150-301 Installation Operation & Maintenance

Pre Start
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
terminals on LTB1 one time to start the Minimum Ventilation Test.
Once the supply fan has started, check for proper rotation. The direction of rotation is indicated by
an arrow on the fan housing.
With the fan operating properly, determine the total system airflow (CFM) by;
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•
Motor Nameplate Amps X Motor HP
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Return Air Smoke Detector

The return air smoke detector is designed to shut off the unit if smoke is sensed in the return air
stream. Sampling the airflow entering the unit at the return air opening performs this function.
In order for the smoke detector to properly sense smoke in the return air stream, the air velocity
entering the unit must be between 500 and 4000 feet per minute.
Equipment covered in this manual will develop an airflow velocity that falls within these limits over
the entire airflow range specified in the evaporator fan performance tables.
There are certain models however, if operated at low airflow, will not develop an airflow velocity
that falls within the required 500 to 4000 feet per minute range.
For these models, the design airflow shall be greater than or equal to the minimum CFM specified
in the table provided below. Failure to follow these instructions will prevent the smoke detector
from performing its design function.
38
Measuring the actual RPM,
Measure the amperage at the supply fan contactor and compare it with the full load amp (FLA)
rating stamped on the motor nameplate.
• Calculate the theoretical BHP
Actual Motor Amps
• Using the fan performance tables in the unit Service Facts, plot the actual RPM (step 1) and
theBHP (step 2a) to obtain the operating CFM.
If the required CFM is too low, (external static pressure is high causing motor HP output to be
below table value),
– Relieve supply and/or return duct static.
– 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. Remove electro mechanical test mode
connections (if applicable).
Table 6, p. 37, momentarily jump across the Test 1 & Test 2
RT-SVX25C-EN