What is the difference between Auxiliary and Emergency Heat?

Auxiliary Heat:

An auxiliary heating source acts as secondary heating source (normally electric) and is enabled similar to a second stage of heating.

Emergency Heat:

An emergency heating source acts as a back-up heating source and will only be enabled if the Heat Pump’s primary heating source fails to heat the room to within 1°F of the heat set point for 1 hour.

What are the configuration options?

Disabled (default): The Heat Pump does not have an auxiliary or emergency heating source.

Auxiliary: The thermostat will enable the Heat Pump as its primary heating source, but if the room does not heat at a 5°F per hour rate, then the Auxiliary heating source will  be enabled. This decisions is made within 10 minutes of running the Heat Pump. The thermostat keeps the Heat Pump enabled when the auxiliary heating source is running.

Emergency: The thermostat will enable the Heat Pump as its primary heating source, but if the heat pump has ran for 1 hour and the room temperature has not reached at least 1°F from the heat set-point, then the emergency heating source will be enabled. The thermostat keeps the Heat Pump enabled when the auxiliary heating source is running.

How do I use this for dual fuel Heat Pump units?

In territories where outdoor temperatures can become extreme cold, it is common to have a dual fuel heat pump unit.

To prevent your Pelican thermostat from enabling the heat pump when it is extremely cold outside: You will need a single outdoor sensor connected to your Pelican Solution. This activates a Compressor Lockout configuration for every thermostat. 

Compressor Lockout is used to prevent thermostats from enabling their heat pump compressors when the outdoor temperature is below a configured temperature. Instead the thermostat will automatically switch to using its secondary/emergency heating source as its primary heat and the compressor(s) will remain Off.