The Large Commercial Technical Support Team has experienced a number of calls from technicians regarding the issue of the Exhaust Fan not energizing during the "Fan On Econ Open" step of test mode. In the majority of these cases the unit is configured with Statitrac (Exh Fan with Space Pressure Pressure control) and with Symbio 700 control the Space pressure control scheme is active during the Service Test Requests. Below is a snip explaining Relief/Exhaust Fan On/Off Requests and how they are generated, but in short, the Space Pressure must be above the Active Space Pressure Setpoint + Deadband AND the Outdoor Air Damper position must be greater than the "Exhaust Enable Position Setpoint" (default is 25%) in order for the exhaust fan to be commanded "On". So in Service Test mode it may be required to temporarily adjust the "Space Static Pressure Setpoint BAS" (Settings>System) to a value low enough to enable the Exhaust Fan Relay and dampers depending on what the active Space pressure is at the time of testing. There is also a link for the Voyager 3 w/Symbio Application guide below if needed.
Voyager 3 w/ Symbio 700 Controls Application Guide
WARNING:
Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.