Service and Parts Manual20Redesign DifferentiationThrough our continuous efforts to improve our product line, U-Line Corporation hasmade some changes to the design of Models Combo 29FF and Combo 75FF.The objective of this section is to assist the service technician in differentiating betweenthe previous design product and the new redesign.The redesign involves a new compressor, evaporator and heat exchanger, condenser fanmotor, evaporator fan motor, drain trough, timer and power cord.To address service problems which may exist in earlier designs, we developed a “Field FixKit.” It involves replacing the compressor, dryer, and hot gas valve. It also includesmounting a sheet of insulation to the back panel. Before installing the new compressor,hot gas bypass valve, and dryer, it is imperative that the entire refrigeration system beblown out with nitrogen to remove any excess oil. This kit is to be installed in units withR-134a only starting with serial number 7CF300000 or 2CF300000. Installationinstructions are included in each kit ordered.The new compressor, a Matsushita Model SD39C replaces the previous compressor, anEmbraco EMI 50 HER.Both the previous design and the new redesign are detailed in this manual. New designunits and previous design units can be differentiated by the serial numbers. All serialnumbers for the new redesigned units start with a number higher than 600000.(Example: 2CF600001 is a new redesigned Combo 29FF.) Previous design units haveserial numbers which start with 300001, 400001, or 500001. (Example:7CF400001 is a previous design Combo 75FF.)Pages 44-45 show the parts breakdown for the previous design of the Combo29FF. The parts replaced with the kit are denoted. The wiring diagram for thismodel is on page 35.Pages 40-41 show the parts breakdown for the previous design of the Combo75FF. The parts replaced with the kit are denoted. The wiring diagram for thismodel is on page 35.Pages 46-47 show the parts breakdown for the new, redesign of the Combo29FF. The wiring diagram for this model is on page 36.Pages 42-43 show the parts breakdown for the new, redesign of the Combo75FF. The wiring diagram for this model is on page 36.FROST FREE UNITS