Bandsaw question

[davelerave]

i connected a single phase bandsaw yesterday

i noticed that the kickstop and the 2 safety door switches are wired in the neutral conductor

the phase/line is wired straight into A1 on starter

i don't do as much industrial as i used to so maybe i'm missing the obvious? is there a reason for this?

thanks

 

[Knobhead]

Yes, it’s wired wrong! E-Stops should be in the live side.

 

[johnboy6083]

in my experience with simple machines like this, the live comes from the control breaker/fuse, goes through the e-stops and the like in series, and then to the a1 in the contactor.
there is usually a terminal bolck, with a link that can be taken out to allow remote e-stopes to be fitted to the machine.

 

[davelerave]

it's a brand new machine and came wired that way

-there's no reverse polarity or anything (the brown core is wired direct into contactor A1)

i noticed this because the machine didn't work right way-there was a wire catching inside the kick stop preventing startup

so it must have been hurriedly assembled and tested(?)

 

[Knobhead]

Wait until you get a sequence fault or even better an earth fault, then you’ll find out why the control should be on the live side.

I’ll leave it to you to work out what I mean.

 

[netblindpaul]

Is this a 230V machine then or 3ph?
As has been said control must be on the live side to comply with statute law in the case of machinery.
Bandsaw make?
If you don't want to put it in open forum, please PM, as I am in personal touch with many of the UK bandsaw importers.

 

[davelerave]

230v-don't have a make

i was surprised but thought maybe i had missed something obvious

 

[netblindpaul]

Colour Dave?

p.s., sorry just re-read, you said 1ph!

 

[Knobhead]

It good that you spotted it, it is downright dangerous!

After thinking about it, is this an American import? 220V over there is often 2ph so an earth fault would blow the fuse. Here with 230 1ph&n an earth fault would render the stops inoperative unless you have a RCD in circuit.

I’ve had many an argument with our American cousins over this point. There is quite a history as to why it was wired this way. It goes back to the 1920’s when there was a shortage of skilled labour. It was easier for their 5 day wonders to fault find, the major problem now is this hangover from the past is now biting them as they adopt 220 1ph&n.

 

[malcolmsanford]

Beat me to it Tony, quite a lot of the 208/230v machines over here have the emergencies in the white cable, for the exact reason you stated, that 208/220 in American and often in the Far East as well, use the 2 phases to get the 208/230v.

 

[netblindpaul]

Tony,
Quite true, but that configuration now makes it illegal to sell and use in the EU after the "new approach" directives have come into place.
Mind it could be just rubbish wiring colours unless the OP actually traced to wiring.
Mind probably Chinese Export designed and wired incorrectly!
Thing is there is no requirement for control fuses in simple machines under current law!

 

[davelerave]

all wiring is 2-core/3-core 1 phase flex

connection is via 16amp inlet socket

safety switches and stop are 'home run' in 2-core br/bl and series'd inside starter

(not wired for 208/230 2-phase/split-phase)

brown core from inlet is connected to coil A1
blue core from inlet is connected to 'start button and hold-on' so it's a simple error

 

[Knobhead]

Simple answer is swapping the incoming mains around in the starter. For god’s sake get the E-Stops on the live side of the supply!

You know about the fault, if there’s an accident you are liable to prosecution in the event of a failure. Get your ar*e out of the fire!

We’ve given the best advice we can, it’s now up to you!

 

[Knobhead]

Sorry I get very bad tempered at times. (I’m taking pills for it) (they don’t work).

I’m not being nasty about this, but knowing there is a fault you leave yourself in a sticky situation. It’s now public knowledge on this board about the fault. In court you’re on a bob sleigh ride in to hell!

Get your ar*e out of the fire and put it right!

 

[davelerave]

yes-i've arranged to call and switch wires

 

[netblindpaul]

Dave,
Switch them in the inlet mate, please take some pics & get me the machine serial no if you can as I'll get the manuf to check the remaining stock in the batch, and possibly issue a notice to the dealers who have machines from the batch in stock.
They will also send this back to the manuf plant.
We may even be able to get a recall type issue done if you can get me sufficient info.
Read the PM before the forum post!
Please read the two in conjunction.

 

[davelerave]

i'm not doing anything for time being

paul-why would you switch the wires at inlet if you were doing it? as polarity and colour coding are correct to starter

 

[netblindpaul]

I have misunderstood then.
I read it as the live from the inlet was going to the incorrect location in the starter.
I have the starter drawing here from the manuf'.
The design and wiring were correct the last time I looked, mind I don't recall any control fuses, they are not required for a simple machine.
TUV have CE marked the machine as it is an Annexe 4 machine which must be inspected & tested by a 3rd party for CE marking.
I am now not sure of what the issue you have is, I understood it as reverse polarity on the supply side in the internal machine wiring?

 

[davelerave]

the power wiring from inlet to motor ,through contactor is correct

they have reverse polarity on the wiring of stop and door switches

simply a matter of switching 2 control wires in starter to correct problem

i appreciate you didn't have benefit of looking at machine



i also notice that 1 pole of the 3-pole thermal overload relay is unused-to my mind this is incorrect

so all in all i've decided not to do anything for the moment

paul-i'll get back to you with a serial number and picture in next few days in case the problem is more widespread

 

[Knobhead]

I give up! What should have taken an apprentice 30 minutes to sort out has taken over a day of qualified time to sort out! Bloody information super highway, I don’t think so!

On the one hand we get 1/2th the information needed, then someone trying to cover up known faults on imported goods.

And by the way the overload, if thermal, is wired wrong! Magnetic, you’ll get away with it.


I haven’t taken my medication for the day yet! I think I need it!

 

[netblindpaul]

Tony,
You need your medication mate.
Your comment about covering up faults on imported goods is slanderous in the least.
My intention is NOT to cover it up if your comment is aimed at me it is to ensure that it is sorted.
The machine will be CE marked any mods you do will invalidate the CE marking thus the compliance with the LVD & the Machinery Directive and thus PUWER98, therefore you will be solely and personally responsible for the machine.
I am awaiting your apolgy.

 

[Engineer54]

Sounds like this machine could have been manufactured in France!! .....Hell, the times i've seen the neutral conductor being used as the switching/control side of things in French stuff doesn't bear thinking about....

Even remember seeing wiring methods of Merlin Gerin components, being shown in one of there catalogues, ... showing the neutral being used on the switching side.
That was a good few years ago mind, whether they still show that in any of there recent publications i don't know!!!

 

[davelerave]

I have misunderstood then.
I read it as the live from the inlet was going to the incorrect location in the starter.
I have the starter drawing here from the manuf'.
The design and wiring were correct the last time I looked, mind I don't recall any control fuses, they are not required for a simple machine.
TUV have CE marked the machine as it is an Annexe 4 machine which must be inspected & tested by a 3rd party for CE marking.
I am now not sure of what the issue you have is, I understood it as reverse polarity on the supply side in the internal machine wiring?

yes-maybe my description didn't make it clear the reversal is only on the control wiring taken from L1 L2 and that the main wiring from inlet through contactor to motor is correct

so obviously only the control wiring can be reversed and not the supply

i'll send on pictures and serial number early next week

 

[Knobhead]

Tony,
You need your medication mate.
Your comment about covering up faults on imported goods is slanderous in the least.
My intention is NOT to cover it up if your comment is aimed at me it is to ensure that it is sorted.
The machine will be CE marked any mods you do will invalidate the CE marking thus the compliance with the LVD & the Machinery Directive and thus PUWER98, therefore you will be solely and personally responsible for the machine.
I am awaiting your apolgy.

I do apologise. I’m not at my best at the moment anti depressants and painkillers mixed with booze aren’t a good mix.

Now I’ll ask nicely, how can a bit of kit get CE conformity when it’s got a blatant problem? I was under the impression that CE marked goods had to be up to a minimum standard. I’ve had to work with the French Bureau de Veritas in the past, I found them to be very lax. But they had to give the seal of approval to all our work for this particular contract. They were passing stuff I wouldn’t let out the gate, in the end the customer sacked them! I for one was glad to see the back of them.

 

[netblindpaul]

OK Tony, apology accepted, thank you.
The machine in question will have been CE marked by TUV of Germany, one of the most respected test houses in the World.
It will have been "type" approved, for serial build.
That is the design and first build will have been accepted, then the machine will be built to that design over its production life, like type approval of road cars for example.
It could be a quality control issue in the factory, we don't know at this stage and unless I get the serial no. we will never know.
This can happen with all manufacturing systems of this type and often happens with cards, think Toyota, Ford, Honda in recent years, and in the electrical world think of the recent mcb recalls by various manufacturers.
This "could possibly" be a similar quality issue rather than a design problem or a fundamental issue with the machine manufacture, or, it could just be a simple misunderstanding due to the way the colours are used as 60204-1 colours do not fully align with 7671.