Trigger time

[blenkie1]

Just had a little talk from our health & safety man at work about vibration white finger or hand arm vibration syndrome as they call it now. He came up with some intresting facts about the grinders we use and how long we can use them for.
We used to have Metabo 5" grinder before they turned rubbish and he claimed they could be used for 4 hours and 5 minutes. Now the new grinders, Fein WS14 5" grinders could be used for 9 hours and 50 minutes! Really? That time is also 'trigger time' where the machine is switched on and applied to work. So is the manufacturer claiming I can use that grinder 365 days a year for 9h and 50mins and not suffer?
I don't use a grinder for half that time and I still get pins and needles in my finger ends on a night. Wonder how its worked out as well, must be with a perfect disc (no lumps out of them) and being used to the grinding disc manufacturers limit (which we don't)
Anyone else been told how long they can use certain tools?

 

[wyn]

I had to use all our hand held power tools in work while a bloke had vibration sensors attached to them.
I think the results we had back were 15 mins max for a 4 1/2" makita.

 

[madkayaker]

there is two standards for vibration testing static and tri axle. tri axle is more accurate and usefull for assesment but many just test the static as that is the min they need to! the measurement wont include and disk or the task it will be tool running on its own.

there is also a big difference in users e.g. age, health and circulation reductions due to smokeing etc

 

[mike os]

as a general rule I try to work on half the manufacturers claim.. so for 8h = max 4h. No real info or reason, just seems "safe"

 

[blenkie1]

I think temperature has a lot to do with HAVS and I think its ok for the health and safety man saying you can use a grinder for nearly 10 hours a day but in the middle of winter with the doors open for ventilation you have to reduce that time by a good amount. No mention of that by Fein so I just assume its 18c to 20c.

Funnily enough Wyn mentioned someone coming into test vibration with sensors. We just had a firm in to test noise and dust levels. He set up 2 men with sensors and the boss set them to work............cleaning up in another part of the workshop!. Result, ventilation not needed and hearing equipment only needed on certain machines, guillotine, folder ,etc. Normally 10 blokes burning, cutting, grinding and welding starts to dim the lights in the workshop theres so much reek!! Boss keeps complaining when I keep opening the doors in the winter. Stinks

 

[Pete.]

HAVS figures only apply to the machine in perfect condition, with a perfectly balanced disk on it. If your machine is worn, out of balance, or if the disk is hammering during work then your times will be severely reduced. Many people are moving away from simply using quoted times and fit reactec-type sensors on the equipment to make sure there's no over-exposure.