How to tell if your Durr VSA 300 suction motor needs servicing.
Dental Equipment maintenance tips from Chris Rickwood | Saturday, 01 April 2017
#2: Does your Durr VSA 300 Dental Suction Motor need a service?
How to tell.
Greetings!
The Durr VSA300 dental wetline suction unit is a favourite among dentists. The design of the unit has hardly changed in 20 years as it has proven so effective in the job it was designed for. Here are a few telltale signs to look out for indicating that the unit needs to be serviced.. of course the cheaper option is to wait until the unit breaks down sending you into a blind panic about the potentially serious lack of income due to closing down the surgery! Think about it.. when a patient comes into your surgery for a checkup he is essentially asking you if his teeth are going to be ok until the next time he comes and sees you, you examine his teeth and tell him off any problems or any likely problems and you suggest repair or preventative measures. Many, many dentists do not feel the need to do this with their own equipment until they 'need a filling' if you like. Here are some things to look or listen out for regarding one of the most critical pieces of equipment in your surgery.
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Noise: Sounds obvious but not all suction units are within earshot.. listen out for extra vibration or a rubbing sound which can indicate that the separator is stuffed full of amalgam. If this is the case then you can check your amalgam pot, if it is full it would suggest that the separator is full too. See my other post on how to change the Durr amalgam pot.
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Heat: After a spell of using the unit carefully touch the bell housing to see how warm it is. You should be able to touch it freely but it can get very hot indeed, this is caused by a buildup of limescale and detritus inside the impellar casing. The impellar is a carbon fibre fan inside the unit that spins to generate the suction which works well but the gap between it and the outer casing is less than 1mm.. debris inside the uit causes friction and the impellar can expand to the point where it will seize. Sometimes it will cool down and contract but sometimes it will not. On a service this bell housing is taken apart by us and the inside cleaned out with Durr MD 555 suction cleaner (awesome stuff). We can often rescue a seized unit in this way. Pull the black cylindrical fan cover from the top of the unit and spin the round plastic blade around, can you hear any rubbing? does it feel smooth when it rotates?
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Smell: Funny (or not so funny) horrible smells? The general cause of this is the one way valve in the piping that stops the water coming back into the unit from the drain will in time swell and thus fail to close properly. These do last a good long while and if this has started to fail then you definately need to get the unit serviced and fully cleaned out.
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Unit struggles to start? Well as described above the general causes are debris inside the bell housing, an expanded impellar or a separator that is full of amalgam which can sometimes weigh over a kilogram (that is a LOT of weight for the unit to try and spin around thousands of times a second.
These are just guidelines but in our experience they are definate things to keep an eye on.
Until next time.
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Next time: #3: Horrible smells coming from your dental suction unit?
