ICE MACHINES Q-Model Service Manual

Section 6Electrical SystemThere are other problems that may cause compressorstart-up failure with a good PTCR in a new, properlywired ice machine.• The voltage at the compressor during start-up is toolow.Manitowoc ice machines are rated at ±10% ofnameplate voltage at compressor start-up. (Ex: Anice machine rated at 208-230 should have acompressor start-up voltage between 187 and 253volts.)• The compressor discharge and suction pressuresare not matched closely enough or equalized.These two pressures must be somewhat equalizedbefore attempting to start the compressor. Theharvest valve (and HPR valve on remotes) energizesfor 45 seconds before the compressor starts, andremains on 5 seconds after the compressor starts.Make sure this is occurring and the harvest valve(and HPR solenoid) coil is functional beforeassuming that the PTCR is bad.CHECKING THE PTCRModelQ200Q280Q320Q420Q450Q600Q800Q1000Q1300Q1600Q1800ManitowocPart NumberCera-MitePart NumberRoomTemperatureResistance8505003 305C20 22-50 Ohms8504993 305C19 18-40 Ohms8504913 305C9 8-22 Ohms! WarningDisconnect electrical power to the entire icemachine at the building electrical disconnect boxbefore proceeding.SV15401. Visually inspect the PTCR. Check for signs ofphysical damage.Figure 6-17. Manitowoc PTCR’s 8505003 & 8504993NOTE: The PTCR case temperature may reach 210°F(100°C) while the compressor is running. This is normal.Do not change a PTCR just because it is hot.2. Wait at least 10 minutes for the PTCR to cool toroom temperature.3. Remove the PTCR from the ice machine.4. Measure the resistance of the PTCR as shownbelow. If the resistance falls outside of theacceptable range, replace it.SV1541Figure 6-18. Manitowoc PTCR 8504913Part No. 80-1100-3 6-43