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How does a PEARL control a Variable Speed Fan (VFD)?

The Pelican PEARL:

A Pelican PEARL can set up to five (5) fan speeds. The speed the fan will be at changes based on the configurations set in the PEARL and how many stages of heating or cooling are active or if just the fan is running.

PEARL configuration options and meanings:

The PEARL will only adjust the fan speed if its configuration called Variable Speed Fan is set to On. Under this configuration you can set in the PEARL what the fan speed will be at for the different HVAC stages (heating, cooling and fan only).

The fan speed configurations for each HVAC stage is set as a percentages from 0% to 100%.

Note: You will want to enable Variable Speed Fan and set the fan speeds even if the PEARL is NOT controlling the fan speed directly. These configurations tell the PEARL that there are fan speed changes.

Variable Speed Fan Settings:

Note: The number of fan speed settings under Variable Speed Fan automatically adjusts based on how many stages of heating and cooling the thermostat is configured for. Here are the available fan speed settings:

Cool Fan Speed – Stage 1: Tells the PEARL what the fan speed should be when 1st stage cooling is enabled.

Cool Fan Speed – Stage 2: Tells the PEARL what the fan speed should be when 2nd stage cooling is enabled.

Heat Fan Speed – Stage 1: Tells the PEARL what the fan speed should be when 1st stage heating is enabled.

Heat Fan Speed – Stage 2: Tells the PEARL what the fan speed should be when 2nd stage heating is enabled.

Ventilation Fan Speed: Tells the PEARL what the fan speed should be when only the fan is enabled.

The (A2) output on a PEARL:

Once the PEARL is configured to control a variable speed fan, its (A2) output will adjust its output voltage to modulate the fan speed. The voltage output range is 0 VDC to 10 VDC.

0 VDC = 0% Fan Speed

10 VDC = 100% Fan Speed.