FG-CAP is a device used to assist in closing the electronic expansion valve in the event of a power outage, serving as an alternative to solenoid valves for the same function.

Used together with the power supply included with the VX-1225 and VX-1250 controllers, FG-CAP v2 employs a backup system based on ultracapacitors and a high-efficiency static converter. For applications using the VX-950 plus controller, FG-CAP v1 must be used.

In the event of a power interruption, the energy stored in the ultracapacitors provides sufficient power to close the electronic expansion valve. Once power is restored, the ultracapacitors are automatically recharged, making the system ready for operation again.