Instruction Manual

MAC 10 ORIGINAL VE5 SERVICE MANUAL
PAGE 16
8 ON/OFF Switch - Speed/Airflow Adjustment
All MAC 10 units are equipped with a three-position rotary switch, which is located on
the side of the electrical box. (See Figure 8)
Recommended fan speed during initial start-up and operation is the “LOW” speed. As
airflow eventually decreases due to filter loading, fan speed may be increased by
moving the rocker switch to the top or “MEDIUM” position, and finally to the “HIGH”
position. Periodic airflow velocity readings (Per I.E.S. Specifications) should be
conducted to determine the filter condition and appropriate fan speed setting.
Figure 8 – 3 Speed Switch Adjustment
Optional Speed Control
Units furnished with the optional speed control (the speed control is standard with 2x2
and 2x3 units) enable adjustment of airflow at any setting within the recommended
performance range. The speed control knob is located on the side of the electrical box,
adjacent to the on/off switch.
Figure 9 - Speed Control Adjustment
Airflow/speed is adjusted by rotating the knob (See Figure 9):
Clockwise à Lowers the speed
Counter-Clockwise à Increases the speed
Fully rotating the speed control knob to the left or counter-clockwise will turn the unit off.
Note : When turning the unit “ON” from the “OFF” position of the speed control, the fan
is at the highest speed. Turning the speed control knob clockwise will lower the airflow.
ON/OFF Switch Electrical Entrance Speed Control
ON/OFF Switch Electrical Entrance 3-Speed Switch