KD (Kelvin/Kooltech) – CellarStar SC Series

Controller shows error (E1, E2, etc.)

– Identify the code: E1 usually = air probe fault, E2 = evaporator probe fault on Dixell XR series. P3 if there’s a third probe (some controllers have defrost termination probe). If the display alternates between temperature and an “E” code, that’s a solid clue. – For E1/E2, check the corresponding sensor. KD evaporators likely have the room sensor on the return air and a coil sensor in the fins. Look for any broken wires or if a sensor got dislodged. – If a code like EE or E0 appears, that might indicate a memory error or parameter error – possibly from a voltage spike or if someone tampered with programming. In such cases, the controller might need reprogramming to default.

– Replace faulty probe: Use the exact type (NTC 10k or whatever is specified). After replacement, most Dixell controllers will clear the error automatically if they read a valid signal (or after a power cycle). – If the code persists, double-check you connected the sensor to the correct terminals and that its cable isn’t run alongside high voltage causing interference. – Reset controller: For memory errors, sometimes entering programming mode and resetting parameters to factory can clear it. If not, a controller swap may be needed. Load the new controller with correct settings (most important: sensor types, setpoint, differential, defrost intervals). – Prevent future probe failures by routing sensor cables away from sharp edges and not pinching them under panels.

Pump-down short cycling

– If the KD system is configured for pump-down, you’ll have a liquid line solenoid valve. Symptoms of trouble: the compressor stops frequently and you hear a faint “click/hiss” each time (solenoid closing and compressor pulling vacuum quickly). The cellar may still cool, but the unit cycles more than normal. – Confirm via the controller if it’s in pump-down mode (some Dixell have a parameter for pump-down or anti-short-cycle). – Check the solenoid coil: is it energizing when it should? With a call for cooling, the coil should be magnetized (you can often feel a slight vibration). If not, measure voltage at coil – if 0V when it should be open, wiring or controller output is suspect. If voltage present but no click, coil is likely burnt out. – Also ensure the thermostat differential is not extremely small; if it’s set to 1°C or less, the system might satisfy and cut off too quickly and frequently.

– Replace solenoid coil if it’s failed. It’s a quick fix – slide the old coil off and new on (matching size and voltage). This should allow refrigerant flow whenever there’s a call for cooling, preventing unnecessary pump-downs in the middle of active cooling demand. – If wiring was wrong (for instance, coil wired to wrong terminal), correct it per the wiring diagram so it energizes properly. – Parameter adjustments: Program a reasonable differential (e.g. 2°C) and an anti-short-cycle delay (Dixell controllers often have a parameter “AC” for minimum compressor off time, set it to e.g. 3 minutes) to avoid rapid cycling. – If for some reason pump-down is not needed (e.g., short pipe runs), one could convert to direct control by keeping the solenoid open constantly or removing it – but normally it’s best to use it as intended for compressor safety on off cycles. Make sure after any changes to observe the unit go through a full cycle to verify the short-cycling is resolved.

Inadequate cooling capacity (Cellar temp hovers above setpoint, unit runs continuously)

– Check if the system is fully charged: perhaps extra refrigerant was needed for longer lines and wasn’t added. Compare actual subcooling or liquid line sight glass condition to expected. If sight glass shows bubbles continuously and pressures are low, likely undercharged. – Ensure the expansion valve (if TXV) is functioning – if superheat is excessively high, the TXV might be misadjusted or partially plugged. – Look at the condenser: if it’s running hot (but not tripping), an undersized condenser or high ambient could reduce capacity. KD units are high performance, but even they have limits if the ambient is 35°C+ in a closed alley. – Evaluate load changes: has the stock in the cellar increased or new equipment introduced? As mentioned, things like an ice machine or glasswasher dumping heat in the cellar can overwhelm a correctly sized cooler. – Verify that doors are sealed and there’s no excessive infiltration of warm air. A broken door closer or frequent door opening can bring in too much heat.

– Top up refrigerant: If low, carefully add refrigerant (R410A as liquid) to reach proper condensing pressure and clear sight glass (if applicable). Be mindful of not overcharging – do this with measured additions and allow system to balance. – If the unit was underestimated for the cellar load, consider adding a second unit or upgrading capacity. Short term, keep cellar door shut and minimize new heat loads. You can also drop the setpoint a tad to keep beer safe if it’s trending warm, but don’t overburden the unit. – TXV service: If a TXV is used (some KD might use capillaries instead), adjust it to obtain recommended superheat (around 5-6K). If unresponsive, replace the TXV and drier. Proper feeding ensures full coil use and capacity. – Ambient mitigation: If the condenser is in blazing sun or a hot attic, try to improve ventilation or shading. Even painting the unit light color or providing a shade canopy can knock a few degrees off. Ensure fan is at full speed; if not, override the fan speed controller in extreme heat so it doesn’t slow down at all. – If structural changes aren’t possible, in a pinch, wet the condenser (spraying water) to boost capacity during peak heat – though not a permanent solution, it shows if high ambient was the limiting factor. – Long-term: if all else fails, an upgrade to a larger model (e.g., from SC050 to SC070) may be warranted. The KD design is modular, so often the evaporator might handle a bigger condenser if pipe sizes allow, but consult with the supplier.

Noise and vibration

– KD units are generally moderate noise (45 dB(A) quoted indoor, 65-ish outdoor). If experiencing loud vibrations, check installation: are the evaporator and condenser both mounted on anti-vibration pads or brackets? Metal-to-metal contact can amplify sound. – Pipe vibration: Ensure refrigerant lines are properly clamped and not touching wooden joists or other structures that can resonate. A throbbing sound might be a liquid line against a beam. – Compressor noise: Scroll or rotary compressors (common in these sizes) usually hum steadily. If you hear rattling, maybe the compressor mounts are loose. If you hear clicking, that’s likely relays or contactors – normal but if too frequent, goes back to short cycling issue. – Fan noise: sometimes fans can rattle if out of balance (a bent blade or debris on it). Inspect fan blades for damage or dirt build-up.

– Secure installation: Tighten mounting bolts, but also add rubber grommets or pads if not present. If wall-mounting evaporator, ensure the brackets are solid and use neoprene washers to dampen vibration if needed. – Isolate piping: Use pipe clamps with rubber inserts to hold the lines. If a line passes through a wall, make sure it has a rubber grommet. Slightly slack loops in long runs can absorb vibration too (don’t tension pipes taut). – Adjust fan or replace: Clean the fan blades. If a blade is bent causing imbalance, either straighten carefully or replace it. Tighten any loose fan guard screws – those can buzz at certain frequencies. – In some cases, adding a simple muffler on the discharge line can reduce pulsation noise (if you feel discharge line strongly pulsing). However, that’s not commonly required for these small units. – Compressor suspension: If the compressor feet are bolted down too rigidly or one is missing a rubber, fix that. The compressor should “float” on its mounts. Replacing perished rubber mounts can greatly cut noise. – Once mechanical fixes are done, measure noise again. If it’s still a concern for customers (for instance if the outdoor unit is near a beer garden), consider installing a sound blanket on the compressor or acoustic enclosure for the condenser – keeping in mind not to restrict airflow.