panel query regarding protection

[Monty2010]

I have received a panel built by someone else as part of a build I am carrying out. Unfortunately the customer has been involved in the selection of devices and wiring requirements however i feel there are a few things a miss.

The mains incomer comes in on a 63A 16mm 5 core SY, through an unfused isolator and into a 63A C rated breaker in 16mm singles, this then goes straight in to a 63A 300mA RCD on 16mm singles. out of the bottom of the RCD is 2 off 4mm singles per phase, 1 of the 4mm is the bus main for a row of breakers which are 2 off 6a, 2 off 16A, 1 off 20 and a 40A the three phases are split over these breakers, the other 4mm from the RCD makes its way to feed a number of contactors and daisy chains from each contactor, becoming the bus wiring.

My issue, surely each circuit should be protected sufficiently to the cable sizing used, so the bus wiring should really all be capable of with standing 63A as that is what it is rated at, or does the RCD change these requirements?

my other issue is the motors only have Overloads, which in my mind only provide overload protection to the motor and therefore the only circuit protection is the MCB 63A and the RCD 63A 300mA. however some motors are fairly small and 1.0mm2 cable has been used from the overload to the terminals in the bottom for me to wire the plant to.
this means that that 1.0mm cable has a 63A breaker protecting it? and a 63A rcd, surely this is not sufficient to rely on an RCD?

In my opinion the motor circuit cables will have to melt, touch earth and then allow the RCD to trip thus being insufficient protection.

I have spent sometime in my regs book but cannot find an actual requirement for overcurrent protection on motor circuits. i have found the statement in 552.1.1 which states every circuit should be capable of carrying FLA, is this enough in my defence to get this panel returned and fixed properly.

Monty

 

[Darkwood]

The relays are due to the guy wanting to run the plant manually? he talked the company in to it for some reason. that's also an issue that I have to pull up with him tomorrow as his relays switch out safety functions and allow the plant to choke.is it not permissible to use a 240V control circuit? or I it ok when used with a 30mA RCD?Where's the cheapest place to buy the 60204 in pdf tonight, mine are at work and could do with a read up now at home.

Where are all the controls on the front door or any remote of the panel?
If the control is 230v where is the isolating transformer? ....

you original question is no the OL of the motors protects the cables from overload its just done downstream rather than upstream ... like netblind says if it aint EC marked and supplied with the relevant documents don't accept it, the more i look at it the more i see and the more i believe its a old hat probably mature sparks / engineer that has not keep up with times.

Regarding my plc comment his reason for so many relays is a fob off it has no bearing on manual control and you already highlight control issues anyway.

Is there a risk element to the user of this machine ... would their be a need for a E stop in your mind?

 

[netblindpaul]

You not seen the MCB's at the top L/H corner? these cover primary of the dc power supply 1p+n and the 3pole is the protection for the star/delta set-up its 400v coils tapped of the incoming to the contactors.

The dc side of the power supply unit is internally O/L protected and S/C protected, no need for external fusing on the dc controls.

Yes I saw MCB's top LH corner, but these are power MCB's black in black out.
Once the wiring leaves the MCB to supply a control circuit, it becomes a control circuit, thus, is is no longer a power circuit?...
Personally I don't believe that the dc side complies without fusing/mcb protection as I can't see what the details of the power supply, so until I do, I have to say it requires protection don't I!

 

[Darkwood]

Yes I saw MCB's top LH corner, but these are power MCB's black in black out.
Once the wiring leaves the MCB to supply a control circuit, it becomes a control circuit, thus, is is no longer a power circuit?...
Personally I don't believe that the dc side complies without fusing/mcb protection as I can't see what the details of the power supply, so until I do, I have to say it requires protection don't I!

http://docs-europe.electrocomponents.com/webdocs/0add/0900766b80addf4e.pdf

 

[Monty2010]

Where are all the controls on the front door or any remote of the panel?
If the control is 230v where is the isolating transformer? ....

you original question is no the OL of the motors protects the cables from overload its just done downstream rather than upstream ... like netblind says if it aint EC marked and supplied with the relevant documents don't accept it, the more i look at it the more i see and the more i believe its a old hat probably mature sparks / engineer that has not keep up with times.

Regarding my plc comment his reason for so many relays is a fob off it has no bearing on manual control and you already highlight control issues anyway.

Is there a risk element to the user of this machine ... would their be a need for a E stop in your mind?

Controls all on front door, except a remote switch for forward/reverse of an auger
There is no isolating TX
E stop circuit feeds first relay, which then feeds control circuit from there.
The spark is about 35, he strikes me as domestic turned panel builder.

 

[Monty2010]

Where are all the controls on the front door or any remote of the panel?If the control is 230v where is the isolating transformer? .... you original question is no the OL of the motors protects the cables from overload its just done downstream rather than upstream ... like netblind says if it aint EC marked and supplied with the relevant documents don't accept it, the more i look at it the more i see and the more i believe its a old hat probably mature sparks / engineer that has not keep up with times.Regarding my plc comment his reason for so many relays is a fob off it has no bearing on manual control and you already highlight control issues anyway.Is there a risk element to the user of this machine ... would their be a need for a E stop in your mind?

Controls all on front door, except a remote switch for forward/reverse of an augerThere is no isolating TXE stop circuit feeds first relay, which then feeds control circuit from there.The spark is about 35, he strikes me as domestic turned panel builder.

 

[Darkwood]

As this is a discussion in an open forum i would remove the schematics and at least blank the company name out at the top... you could find yourself in a legal tangle if this thread is brought to his attention as he could seek defamation.

Ps my Bedtime CYL

 

[Monty2010]

As this is a discussion in an open forum i would remove the schematics and at least blank the company name out at the top... you could find yourself in a legal tangle if this thread is brought to his attention as he could seek defamation.

Ps my Bedtime CYL

Yep same here, cheers for your input, drawings removed, I looked passed the name on them and missed it.

 

[Lagentium]

Those inverters are so user friendly it's unreal darkwood, that panels a right state too (tongue in cheek!)

 

[wozz]

As this is a discussion in an open forum i would remove the schematics and at least blank the company name out at the top... you could find yourself in a legal tangle if this thread is brought to his attention as he could seek defamation.

Ps my Bedtime CYL

Whilst I agree it's not a good idea to put a company name to it and I'm by no means a legal expert but I was told if you stick to fact and opinion you are ok, the fact is that is how the panel is, the op is asking for clarification on some points which in his opinion may not ok. There are far worse things that people say on here that are accepted , I really can't see a company spending time and effort going after someone for questioning a product. If they did it would make interesting reading as you would be free to tell people they are perusing you.

 

[Darkwood]

Whilst I agree it's not a good idea to put a company name to it and I'm by no means a legal expert but I was told if you stick to fact and opinion you are ok, the fact is that is how the panel is, the op is asking for clarification on some points which in his opinion may not ok. There are far worse things that people say on here that are accepted , I really can't see a company spending time and effort going after someone for questioning a product. If they did it would make interesting reading as you would be free to tell people they are perusing you.

Its more a forum policy too and when discrediting someone's work in the public eye if you name them or their company then those been discredited have the right to defend their actions and as they are not part of the conversation it can easily get to a stage where defamation is used.

Although we are discussing the BS60204-1 in particular here its wording in many area is 'preferably' - 'recommended' and many clauses have sub clauses which allow agreed deviations from the regs ...eg - colour coding of indicator lights may conflict with existing plant controls and thus an agreement is reached you will deviate from regulation and bring the panel in line with existing plant control colour codes.

From our observing point of view we have been given limited info so can only comment on what we see which could be misleading as we don't know the exact spec of the control system or any agreed excursions from regulations although we can point out where we feel the panel doesn't seem to be in line the LVD and more specifically 60204 - 1 as our discussion goes.

Like the BS7671 the Bs 60204 is a guide and there is as far as I know no legal requirement to follow it in the uk at least but there is a legal requirement to meet the health and safety issues in the directive thus following the relevant BS standards forms the best and easiest route to achieving this.

 

[Monty2010]

Update, panel builder drove 4.5hrs up to me today to ask what my concerns were.
after reading through 60204 and finding the c,artifices tigon I required on over-current protection I began explaining all his other faults. The panel has gone home with him, I believe he is rectifying it.

Biggest problem is he was ready on the counter attack and I think still doesn't see what's the problem with his panel. It's coming back up on the twelfth so will see if it's improved. Also major alterations to the control circuit.

and one to net Paul, you can use phase voltage for control circuit without an isolating TX, see method 3.

 

[Monty2010]

Its more a forum policy too and when discrediting someone's work in the public eye if you name them or their company then those been discredited have the right to defend their actions and as they are not part of the conversation it can easily get to a stage where defamation is used.

Although we are discussing the BS60204-1 in particular here its wording in many area is 'preferably' - 'recommended' and many clauses have sub clauses which allow agreed deviations from the regs ...eg - colour coding of indicator lights may conflict with existing plant controls and thus an agreement is reached you will deviate from regulation and bring the panel in line with existing plant control colour codes.

From our observing point of view we have been given limited info so can only comment on what we see which could be misleading as we don't know the exact spec of the control system or any agreed excursions from regulations although we can point out where we feel the panel doesn't seem to be in line the LVD and more specifically 60204 - 1 as our discussion goes.

Like the BS7671 the Bs 60204 is a guide and there is as far as I know no legal requirement to follow it in the uk at least but there is a legal requirement to meet the health and safety issues in the directive thus following the relevant BS standards forms the best and easiest route to achieving this.

Darkwood, i with you and thus is why I removed it, you can soon get yourself in a little trouble by shaming people and them taking offence if it's true in your opinion or not. This is why I took your advice and removed the details. Thanks fella for the rest of the info

 

[netblindpaul]

Update, panel builder drove 4.5hrs up to me today to ask what my concerns were.
after reading through 60204 and finding the c,artifices tigon I required on over-current protection I began explaining all his other faults. The panel has gone home with him, I believe he is rectifying it.

Biggest problem is he was ready on the counter attack and I think still doesn't see what's the problem with his panel. It's coming back up on the twelfth so will see if it's improved. Also major alterations to the control circuit.

and one to net Paul, you can use phase voltage for control circuit without an isolating TX, see method 3.

Well in that case your copy of BS EN 60204-1:2006+A1:2009 is different to mine.
There is no "method 3" anywhere in my copy.
I have just checked again with a fresh copy from BSI in case mine is corrupt, and nope not there.
I suggest that you refer to clause 9.1.1 in this standard for clarity of the requirement.

I have put an excerpt below, it would be illegal to provide too much of the standard.
Excerpt from BS EN 60204-1:2006+A1:2009.
>>>>>>>>>>>
9.1 Control circuits
9.1.1 Control circuit supply
Where control circuits are supplied from an a.c. source, control transformers shall be used for
supplying the control circuits. Such transformers shall have separate windings. Where
several transformers are used, it is recommended that the windings of those transformers be
connected in such a manner that the secondary voltages are in phase.
Where d.c. control circuits derived from an a.c. supply are connected to the protective
bonding circuit (see 8.2.1), they shall be supplied from a separate winding of the a.c. control
circuit transformer or by another control circuit transformer.
NOTE Switch-mode units fitted with transformers having separate windings in accordance with IEC 61558-2-17
meet this requirement.
Transformers are not mandatory for machines with a single motor starter and/or a maximum
of two control devices (for example interlock device, start/stop control station).
<<<<<<<

There is NO way this panel would comply with the last paragraph stating that "transformers are not mandatory"

Don't bother trying to argue, because I won't argue with you.
You can read the facts above.
You won't win by the way, even if you start an argument.

I am not liked on here, because I HAVE to keep up with current legislation and current practice, and, I have to provide evidence of such material breaches that you are seeing here, regularly, as it is part of my business, and I am not afraid of stating very directly when things are wrong.
IF things are just my opinion then I will state this, however, the fact here is that that panel requires a transformer, you cannot use a control supply direct from the mains and comply with "60204".
Have you asked the panel builder for his RA's & safety assessments for the control system?
Have you asked him for his DOI for the panel?

 

[Darkwood]

I think he's referring to 9.4.3.1 (method c) but this is in respect to protection against maloperation due to earth faults, voltage interuption and loss of circuit continuity.

Where it brings up method C it mentions where the control circuit is not fed from a control TX so i think this is where the panel builder is confused as he thinks its a non restricted option and not guided by the conditions in 9.1.1.

PS Netblind... I have no issues with you I know you know your stuff and respect your comment whether or not I may agree fully or not, BTW regarding the fusing of my DC supply did you take a look at the link?.. Would the DC side in your opinion need external fusing as I have omitted it? The supply will be cut on OL or SC and won't re-establish without both re-power and no fault/OL conditions.

@Monty .. regardless of the panel builders excuses the fact that he taken it away to bring it more in line with regulations must be screaming out to you his competence... I still can believe the exposed incoming tabs so close to the cab case without room to lug up..that just says it all regardless of any other issues.

Im still unsure of the machine set-up but can't really believe this machine is hazard free and doesn't require some kind of E-stop circuit?

 

[GMES]

The 1st thing i would be complaining about is all the cheap chint crap in there! sorry guys but it is the cheapest control gear on the market.
For me in an industrial enviroment where stuff gets a lot of work i would really want better quality parts in my panel.