All machines have a mechanical override, you need the tool provided with the centrifuge or a thin piece of metal such as a very thin screwdriver or small Allen key.

If you don’t have the correct tool and your improvising then your makeshift tool needs to be 1.5mm dia and 3cm long for all models except the Mistral 1000 when it needs to be at least 5cm long. Always ensure centrifuge has stopped and is disconnected from the supply.

Insert tool into hole. The hole for the mechanical override is in different positions on different centrifuges as follows:

Microcentaur Left hand side on main chassis, Push tool in about 3cm.

Centaur 2 Top centre of lid, 8cm from front. Pivot tool towards you.

Hawk 15/80 Left hand side. Pivot tool toward you.

Harrier To left of the lid opening mechanism, insert tool and pivot to the right.

Mistral 1000 Left hand side of chassis, push tool straight in tool must be at least 5cm long.

Falcon Top of lid 6cm from front pivot toward you.

Cellcep and Mistral 6000 Right hand side top of lid, 22cm from the rear, pivot to the right.

The centrifuge is designed to cut out if an out of balance occurs. First check that the buckets are evenly balanced, the maximum allowed is in general about 10gms on adjacent buckets and 5gms on opposite buckets.

Remove the buckets if it is a swing out rotor and run the centrifuge with just the rotor in place. If the centrifuge now runs smoothly weigh the buckets to ensure they are of equal weight, often the inserts/cushions get mixed up during cleaning, thus making the overall bucket weights uneven.

Buckets at times do not swing out correctly during the run due to dirt or dried grease on the trunnion pins that the bucket sits on. Clean and lubricate trunnions and bucket slots.

Check that with the buckets on the rotor they swing up to the horizontal position freely, then try the same with tubes in place as the tubes may be too long and be catching on the rotor.

The out of balance detector may be too sensitive. All centrifuges in general will cut out at about 500 to 1000 rpm to prevent damage to the machine if an out of balance is detected. The set up of the out of balance detector will require an engineer.

Often users operate the centrifuge without performing a pre-cool. The motor in the centrifuge generates heat and the cooling comes from the rotor bowl, it is unrealistic to start a centrifuge at ambient temperature and run it at full speed and expect the refrigerator to pull the temperature down to say 3 degrees on a 10 minute run.

We advise you to run the centrifuge with no samples in the rotor at the required temperature at a low speed such as 800 rpm for 15 minutes to allow the bowl and rotor to equilibrate at the set temperature. Then put samples in and run as normal.

After use all refrigerated centrifuges should be left with the lid open to allow the frost on the inside of the bowl to evaporate. If the lid is shut after use the frost melts in the bowl and remains in the bowl, this can cause corrosion and is the main reason for damage to the top bearings in the motor or drive assembly often with the result in a complete seizure of the bearing. This can be a costly operator error, always leave the lid open.

Sometimes the out of balance switch jam’s in transit, try to move the motor and rotor about, just by this action the out of balance switch will re-seat itself and the problem is resolved.