Thermolec Plenum Heater - Manual (Page 3)

FIELD TESTS:
A. BEFORE Installation of the Add-on Heater:
1. Ensure that the burner does not cycle due to repeated operation of the furnaces high limit control.
2. Determine whether stabilized outlet air temperature during burner operation is below 66°C (150°F) in the main
outlet duct. If it does exceed 66°C (150°F) make the following adjustments to the Ventilation System in
progressive steps:
Note: In most cases, only steps A & B will be necessary.
a) Check if filters are clogged.
b) Check if fan blades are clean. If not, remove the blower from its compartment and clean with a brush.
c) Adjust the motor pulley to increase its diameter.
d) Change the fan pulley for a smaller size.
e) Change the motor pulley for a larger size.
f)
Change the motor and make sure that the fan control and wiring are adequate.
Note: If steps c), d) & e) are necessary, make sure that the existing motor is adequate. The current drawn must not
exceed the nameplate specifications.
Important: The blower must not be changed. If the system cannot provide sufficient airflow after changing the motor,
do not install the add-on heater in that furnace.
B. AFTER installation of the Add-on Heater:
1. Ensure that the burner does not cycle due to repeating operation of the furnace's high limit control.
2. Ensure that stabilized outlet air temperature during burner operation does not exceed 72°C (160°F) in the main
outlet duct.
3. Run burner to ensure that the blower starts soon enough to prevent the manually resettable temperature limiting
control on the Add-on Heater from tripping.
4. Operate the Add-on Heater to ensure satisfactory operation without overheating.
Note: Where a cooling coil is present, additional checks should be made to ensure adequate airflow exists for cooling
system operation.
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