Product Description:

The 135U1788 is a variable frequency drive produced by Danfoss for the VLT FC 103 Refrigeration Drives series within the VLT Refrigeration Drive product group. It modulates the speed of three-phase compressors, condenser fans, and evaporator fans so refrigeration systems can respond to changes in thermal load without relying on mechanical throttling. By varying the motor frequency, the drive reduces energy consumption, limits startup current, and helps maintain stable suction pressure. These control capabilities support refrigeration equipment that must operate efficiently across changing cooling demands.

The drive accepts a line supply of 200–240 VAC from a three-phase network. It can deliver up to 15 kW of continuous electrical output, corresponding to a shaft output of 20 HP. An integrated RFI filter meets Class A2 limits, while the enclosure has an IP21 / Type 1 rating for installation in clean, dry indoor locations. A fuse is included as the mains protection option to protect the upstream wiring from excessive current. The drive has no brake chopper, so an external solution is required when rapid deceleration produces regenerative energy. Its printed circuit boards do not have a conformal coating, making appropriate humidity control and protection from condensation important. Adaptation B is not applied, and the B, C0, C1, and D option slots are not equipped.

Field communication is provided through the AK-LonWorks MCA 107 card installed in the A option slot. Wiring is routed through standard cable entries associated with Adaptation A, allowing normal power and control cable installation. The drive is supplied without a local control panel, so parameter access requires remote tools or a compatible optional LCP accessory. The Class A2 filtering helps reduce conducted radio-frequency emissions that could otherwise affect equipment connected to the same electrical system. The Series 103 configuration uses the mechanical arrangement associated with other FC 103 refrigeration drives.