QuietFan Installation Guide

Quiet Fan

Blower Speed Control

A triac is the most commonly used method, in marine HVAC applications, to vary

the speed of a fan or blower. This method generates a low frequency hum in the fan

particularly at low speeds. The Blower Speed Control (BSC) eliminates this hum.

The BSC is suitable for any single phase motor. It has thermal and over current

protection. Reprogramming the HVAC control may be necessary to achieve desirable

blower speed.

The “Status” LED, which is located next to the “FAN” terminal, will stay on

when the power is fully supplied to the blower. The “Status” LED will flash slowly

(approximately once per second) after an over current condition is detected. The “Status”

LED will flash fast (approximately three times per second) after an overheat condition

has been detected. Over current and overheat conditions will reduce the fan output to

33%. To restore normal operation after an over heat or over current fault, remove power

from the “IN” terminal. This can be accomplished by turning the HVAC control off for 5

minutes. “Overload” and “Overheating” conditions are caused by the blower failure and

must be rectified before making an attempt to resume the operation of the BSC.

CONNECTING THE BLOWERSPEEDCONTROL:

Caution: Disconnect the AC power to the HVAC system before connecting the BSC.

CONNECT ONLY the fan motor to the SilentFan output terminals.

Caution: AC L1 and L2 polarity must be observed; wire the BSC directly to the HVAC

system controller as shown on the wiring diagram.

Caution: Short circuit on the “FAN” output will permanently damage the BSC. Make

sure the motor does not exceed 2.4 Amps and is not shorted before connecting to the

BSC.

Caution: This unit creates some heat during operation that will cause the case to become

warm to hot. The unit should be installed as close to the air handler as possible within the

air conditioned space.

Caution: Unit will operate with a single shaded pole motor. Dual shaded pole motors

may not operate no matter the combined current draw. Dual shaded pole fan motor

operation is not recommended.

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Quiet Fan Blower Speed Control A triac is the most commonly used method, in marine HVAC applications, to vary the speed of a fan or blower. This method generates a low frequency hum in the fan particularly at low speeds. The Blower Speed Control (BSC) eliminates this hum. The BSC is suitable for any single phase motor. It has thermal and over current protection. Reprogramming the HVAC control may be necessary to achieve desirable blower speed.
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Specifications: AC Line Voltage: 180-240 VAC AC Line Frequency: 50-60 Hz Maximum blower current: 2 Amps Over current threshold 2.4 Amps Relative Humidity Limits (RH) 10-95% Non-Condensing Ambient operating temperature: 0°F to 130°F (-17.7°C to 54.4°C) Rev 2 12/5/2012 ©2011 Micro Air Corp.