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I have just bought a bandsaw. It has an On switch and an Off switch.
However the Off switch does not respond to a loss of power, and is actually quite tough to manually activate.
Even my dust extractor system has a zero volt kill switch.
Is this BS switchgear legal?
Hi, Carbatec also uses that system, at least on some benchsaws; it is bloody dangerous, to say the least...if the overload switch kicks in, when you reset, it starts with no warning!
Bad recipe for any fingers close by!:no:
We have one of those in our club, glad to report it is being thrown out soon!
hmm...so it is legal, even though pretty bad. I have old gear that has no cutout switch and my problem was brief power outages of maybe 5 seconds or so. So _really_ dangerous.
I think I will change this one.
It's interesting to note that even the humble Triton was fitted with a safety switch when sold in the UK. Unfortunately we are under regulated in the hobby tool market, if those items were sold into schools or industry they would need to be retrofitted with a No Volt Release switch to comply with OH&S rules.Quote:
Originally Posted by REALOldNick
Regards
Gragame
Yeah sometimes EU is a bit granny, but I really was surprised that this one got through here, these days. Once I used a machine with the "proper" switch, I would not happily go away from them.
Thanks for the pointer on the NVCO switches.
from an electrical regulatory point of view I do not believe there is any requirement that I know of for a DOL starter (no violt switch) on any equipment.
Any requirement in an industrial workplace will come under OH&S....but I do not believe there is a specific legeslative requirement.
I would be very surprised to see such a machine in any caring workplace with out one though.
It would come very high on the list in any risk assessment.
They are easy enough to obtain and straight forward to fit.
cheers
My bandsaw is in the same boat. Anyone know of a good source for a reasonably priced switch?
Almost any electrical wholsaler should be able to supply... but..I got my last one from Garry Pye as a jet spare part.
cheers
Hi
Let's be clear there are many types of switches. A true safety switch a.k.a Direct Online Starter has a contactor or relay that ensures the the switch only works when there is power available i.e. No Volt Release.
Other safety switch look alikes are usually just on - off switches adapted with a mushroom head on the stop or a paddle as per the Triton version, some have a latching off button. In some applications this is all that is needed e.g. dust extractors. However, IMHO true NVR switches should be used in any fixed cutting application, router tables, saw benches etc.
Most DOL starters also have a built in overload protection, which realy isn't needed where the motor has its own protection
I hope that this clarifies the situation a little.
Regards
Grahame
Good point.Quote:
Originally Posted by Gwhat
Last time I looked, RS components had 240V 10A no volt release assemblies for about $35 and a similar assembly as a spare part for an MC900 wood lathe from Hare and Forbes was $20. Both are the familiar green and red button in black housing with clear rubber over the top to keep a bit of the dust out.
Hope this helps a bit.
WooHoo! Ok. Thanks. I was trying to replace a smashed one on an extractor from timbecon and said they had none
OK Both dem sites is powful big. Any narrowin? I mean u dun looked an all
Yeah the RS site is huge. Farnell are about the same, they must spend so much $ keeping it up to date.Quote:
Originally Posted by REALOldNick
The page of no volt switches they carry is here:
RS Australia | World Leading Distributor of Electronics, Electromechanical and Industrial Components
Beware that they do stock some 115V switches which are NOT suitable for Australian (240V) supply.
These are the two I was looking at:
Attachment 172151
$33 ex GST
EICHOFF | Relays, Switches and Indicators | Switches | Push Button Switches | Switch Disconnectors - Fuses |3251-20-01/52
Attachment 172152
$37.60 ex GST
EICHOFF | Relays, Switches and Indicators | Switches | Push Button Switches | Switch Disconnectors - Fuses |3251-21-01/52
I see that the clear dust cap I mentioned was on one of the 115V switches so it would be no good.
The smaller fifth lug on that first switch is for adding in extra safety/convenience stop switches.
Do me a favour and have a chat with a registered repairer or sparky and they will be able to give you the final yay or nay. I can show you where to shop but I can't help you wire it up, sorry.
Good Luck :2tsup:
YEH bothe those look a bit weedy, my band saw had a cheap realy op switch in it standard.....did not last.
one of the most common issues with cheap imported gear is cheap switch gear.
go for a full sized DOL starter.
Ring Garry Pye woodworking.
expect to pay arround $100 give or take for a generic one.
As I said Any electrical wholesaler will be able to supply one, but probaly under a brand name and arround $150.
cheers
A bit weedy? Is 16A on a single phase machine not enough for you? I would completely agree for a three phase machine where there is much higher inrush, hence the heavy contactor rated 20A+. I would be interested to see what actualy is inside one of these $100-150 boxes that justifies the cost. The switches activated by the buttons on the front of these dol boxes are not very different (rating) to what I have posted here.
I have come across a little trouble with dust getting into these switches but electrically you don't need much to drive a 2hp machine.
Happy to be proven wrong but I'd like to see it backed up...
A bit weedy... yep cheap moulded plastic, snap together construction and staked terminals.
Sorry its a cheap crappy piece of switch gear suitable only for light duty applications, like those little tile cutters, scroll saws and other bench top equipment......probably OK on a small drill press
wots in a dol starter that makes them so expensive.....proper industrial switch gear.
a full set of clamp type screw terminals, including earth connections
a proper fullsized contactor with multiple 500 volt rated contacts..contacts that can be cleaned if necessary.
configured for single phase provides complete isolation of the motor from the supply
Contacts that are rated for heavy motor starting.....my saw bench draws over 50 amps on start up and runs on a 20 amp circuit......its suposed to be 3Hp
My band saw is suposed to be 2 HP and came fitted with a 15 amp plug, I have not measured its peak start current but I expect it to be arround 30 to 40 amps
A fully servicable device
an adjustable overload device
the ability to connect external switches to activate start and stop function or for interlocks.
all that in a substantial IP rated case with proper and multiple cable entries.
the better and more expensive brands you can buy most components of the unit as spare parts
That is why that are called a starter, because there is more to them that a switch....they are a complete motor management system in a box.
are all those features used...well yess.
My band saw has interlocks on the doors, as is required under most OHS recommendations.
I have triggered the overload on the saw bench a couple of times when I have been a little ...um..ambitious.
I did have a motor blow up on the band saw before i replaced its starter with a real one.....it was replaced under waranty... but may have never blown if there was an overload in the original starter.
One of these days I will wire a toe bar kill switch on the saw bench..as it came there is a mushroom button stop switch on the left hand side of the machine so you dont have to "cross the blade" to stop the machine.
serioulsy..for anything with a decent sized motor....any stationary machine over 1hp, they are a realy good idea.
cheers
Soundman that's a good explanation. I do not argue that the you are paying for something that will do everything and last for the life of the machine.
Couple of points to note:
- On the smaller machine the motor itself often has thermal overload incorporated into it's starter circuit
- Additional stop switches or e switches are wired in series with the hold in coil, wether its industrial switch gear or these units, so choosing between the two will not limit this feature.
For my money, I'm just suggesting that the full starter boxes are not the only option.
As far as thermal overloads in motors...tru some do....a hell of a lot dont...some motors have a no resetable thermal fuse....blow that and your motor is shot.
As for the external switches.....have a good look at the switch pictured.....if you want external switches you have to specify the unit with the extra connector and that will probaly only be the hold up circuit it wont allow you a remote start.
An fulls sized DOL starter certainly is not the only option...but on any decent sized piece of stationary equipment they are by far the best option.
would I use one of those cheap items......yes I would...perhaps on drill press...they would be an ideal replacement for the cheap rockers or toggles that come supplied on most...they would also go well on smaller sanders..... but realy they are limited to smaller mostly bench top items.
another issue is that the switch pictured requires some sort of cavity so it can be flush mounted, or it would have to be mounted in a suitable box.
cheers
Good point about the remote start, I didn't think of that. Looking at the wiring diagram I'd say you're right. Not like just putting another "start" button in parallel.
Good discussion, hope others can learn from it like I have.
Well yeh it is....but those little switches dont give access to do so.
strat buttons in paralell, stop buttons and interlocks in series
cheers