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How many Cool Stages do I select for a thermostat?

Select the number of primary Cooling Stages the thermostat directly controls.

What are the configuration options?

1: The thermostat enables (1) primary cooling sources.

2: The thermostat enables (2) primary cooling sources.

What are Primary versus Secondary cooling sources?

Primary are the main cooling sources. For example, compressors are consider primary cooling sources.

Secondary would be an economizer, this would not be considered a “cooling stage” in the thermostat configurations.

What does (0) stages of cooling do?

Zero (0) cooling stages tells the thermostat that there is no primary cooling sources available. This also means the thermostat will not allow a cooling set-point. This prevents a user from accidently try to turn cooling On.

Note: If there is a PEARL economizer controller, and if the only source of cooling the outdoor air, then you will still want to set Cool Stages to zero (0). The thermostat will still allow for cooling when outdoor temperature allow the economizer to be active.

What about (3) stages of cooling?

If your air handler has three (3) primary cooling stages, Pelican Technical Support can configure the thermostat for three (3) stages. For this to work correctly, you will need to follow Pelican’s three (3) stage mechanical cooling wiring diagram.

Note: If there is a PEARL economizer controller and two stages of mechanical cooling, then you will want to set Cool Stages to two (2) since the thermostat automatically makes the economizer the third stage.

What if I have a floating chilled water valve?

Set Cool Stages to one (1). Then contact Pelican Technical Support to configure the thermostat for “Floating” control.

Floating control tells the thermostat to use (Y) to open the valve and (Y2) to close the valve.

What if I have a modulating compressor or valve?

Set Cool Stages to two (2). Then contact Pelican Technical Support to configure the thermostat for “Variable” control.

Variable control tells the thermostat to use either (A1) or (A2), from a Pelican PEARL, to modulate the cooling source. 

Note: If the PEARL is controlling an outdoor damper, then you must use (A1) as the outdoor damper control signal output. Therefore, you would use (A2) as the chilled water control output).

Setting two (2) stages of cooling tells the thermostat a target different supply temperatures based on how much cooling demand the space has. This is also known as a “reset” cooling target.

What if I have a two-pipe fan coil?

Set Cool Stages to one (1). Then contact Pelican Technical Support to configure the thermostat for “Two-Pipe Fan Coil” control.

For Two-Pipe Fan Coil to operate, you will also need a single Pelican “common” supply water temperature sensor on your water loop. Technical Support can link this single water temperature to all your Two-Pipe Fan Coil thermostats. If the water is hot, then the thermostats will automatically only allow for heating. If the water is cold, then the thermostat will automatically only allow for cooling.

What if I have a face-and-bypass unit ventilator?

If the unit ventilator has a two-position face-and-bypass damper and a modulating chilled water valve, set Cool Stages to (2) and contact Pelican Technical Support to enable “Variable” and “Face-and-Bypass” Control.

If the unit ventilator has a modulating face-and-bypass damper and a two-position chilled water valve, set Cool Stages to (2) and contact Pelican Technical Support to enable “Variable” and “Face-and-Bypass” Control.

If the unit ventilator has a modulating face-and-bypass damper and a single cooling source, set Cool Stages to (1) and contact Pelican Technical Support to enable “Variable” Control.

If the unit ventilator has a two-position face-and-bypass damper and a single cooling source, set Cool Stages to (1) and contact Pelican Technical Support to enable “Face-and-Bypass” Control.

If the unit ventilator has a modulating face-and-bypass damper and two cooling source, set Cool Stages to (2) and contact Pelican Technical Support to enable “Variable” Control.

If the unit ventilator has a two-position face-and-bypass damper and two cooling source, set Cool Stages to (2) and contact Pelican Technical Support to enable “Face-and-Bypass” Control.