Units with no ductwork have air volumes predetermined at
the factory by supply grille size and normally do not require
air balancing other than selecting the desired fan speed.
Units furnished with optional dampers on supply grilles may
require some small adjustments to “fine tune” the air delivery
to each grille. Opposed blade balancing dampers are not
available for all grilles on a unit with electric heat.
After proper system operation is established, the actual unit
air delivery and the actual fan motor amperage draw for
each unit should be recorded in a convenient place for future
reference.
Control Board Adjustment.
Adjusting the Low, Medium and High potentiometer
requires the use of Multi-meter capable of measuring
0~10 VDC.
CAUTION: Only trained and qualified
individuals should attempt to adjust or service
components on any energized electrical equipment.
Failure to follow established safety rules and guidelines
could result in serious injury or death.
When unit is shipped from the factory with motor control
board (which has Hi, Med and Low airflow settings), it is pre-
programmed at the factory to “High” speed and delivers the
airflow and cooling/heating capacity specified at the time
of order, while Medium and Low Speeds are set to defaults
based on High speed. Should airflow require adjustment
after installation, the control board settings for Low, Medium
and High could be adjusted by turning screws(as shown in
the picture) using a small Phillips Screwdriver. It will adjust
the control voltage to the motor. A clockwise rotation
increases the voltage to the motor, while counter clockwise
rotation reduces it.
CAUTION: Both of the procedures described
below require the control box to be powered
while adjustments are made. Line voltage
components are concealed behind a
secondary cover. However, installer should still take all
reasonable precautions.
Unit must be powered to perform the following procedure.
Set the electrical multimeter to VDC (Volts Direct Current).
Attach black negative (-) lead of meter to the terminal
labeled “L2” (shown above the potentiometers).
Attach the RED positive (+) lead of the meter to the terminal
labeled “L1” and confirm that there is approximately 5~10
VDC present.
Attach the RED positive (+) lead of the meter to the DC OUT-
PUTS. LOW, MED & HIGH are typically connected together.
1. Close either the LOW, MED & HIGH speed relay contacts
by applying 24 VAC to the corresponding LOW, MED or
HIGH 24 VAC INPUT and COM.
2. Measure voltage at the DC OUTPUTS and adjust the
potentiometer for that speed. (VR1 LOW, VR2 MED, VR3
HIGH)
3. In order to achieve higher CFM, turn the potentiometer
Clock-Wise .
NOTE: For specific voltages adjustment please contact IEC
factory representative.
Potentiometer
Low, Med, High CFM adjust
20
20
Modular Hi-Rise Series Fan Coils
INSTALLATION, OPERATION, & MAINTENANCE MANUAL
