Wiring/Termination standard

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mehdi1351

Member
Location
New Zealand
Occupation
Electrical Engineer
Hello,
I am new to US market/industry and we are going to build a project in Texas and I am wondering to know whether there is any special codes/standard/regulation that a system integrator shall follow to manufacture/construct a PLC panel?
The PLC panel shall housed the PLC controller, motor VFDs, main power isolators etc.
 

tom baker

First Chief Moderator & NEC Expert
Staff member
Location
Bremerton, Washington
Occupation
Master Electrician
Probably UL508A. You will need to get approved as a 508 shop. In WA if there is a control panel and it does not have UL 508 label the job stops.
There are other companies that can do control panel listing but this is an area I am not familiar with
 

mehdi1351

Member
Location
New Zealand
Occupation
Electrical Engineer
Probably UL508A. You will need to get approved as a 508 shop. In WA if there is a control panel and it does not have UL 508 label the job stops.
There are other companies that can do control panel listing but this is an area I am not familiar with
Yes, this is exactly the things that concerning me. I want to know whether a control panel with no medium voltage ( just a 3ph 380VAC feeding Siemens VFDs) need to be UL listed in Texas province?
I do understand the switchgears, MCCs power distribution boards etc need to comply with some regulatory like UL, but is that the case for the PLC cabinets?
Second question:
what is the difference between UL508 and NEC409.2 as industrial control panel construction perspective?
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
It is not UL508, it is UL508a that is for generic control panels. UL508 is for certain control components.

You can get listed to the UL508a standard by UL, ETL, and CSA. There may be other NRTLs that can do it but it is the same standard.

Read what the NEC says and industrial control panel is in article 409. It is the definition that UL508a uses.

It is not a difficult standard to build to.

Texas is a state not a province. States are sovereign entities. Provinces are not.

Some jurisdictions require industrial control panels be listed, some do not. OSHA more or less requires them to be listed but does not seem to enforce it. Many companies require it in their specifications.
 

Macbeth

Member
Location
Livonia NY
Occupation
Automation
Under ul508a you would have to build within the US. The Shop Flood acquires the Certification not the Company. Now that's Just the Base.. Depending on function other codes may supersede.

Such as we are currently being dinged for an indicator lamp located on a common control panel..

"Emergency alarm equipment or control panels containing emergency alarm equipment are covered by the Standard for General-Purpose Signaling Devices and Systems, UL 2017"

Since we used the word "System Alarm" UL forbid us from labeling it to UL508a... They are claiming any indicator Lamp labeled "Alarm" is UL2017..

The system alarm is not required by any Jurisdiction, But for some reason they think any lamp labeled alarm must be attached to the fire panel.. I have no Idea why we need the alarm company to know a conveyor motor tripped? We removed the indicator light and have it on the HMI only now and all is OK.
 

mehdi1351

Member
Location
New Zealand
Occupation
Electrical Engineer
Under ul508a you would have to build within the US. The Shop Flood acquires the Certification not the Company. Now that's Just the Base.. Depending on function other codes may supersede.

Such as we are currently being dinged for an indicator lamp located on a common control panel..

"Emergency alarm equipment or control panels containing emergency alarm equipment are covered by the Standard for General-Purpose Signaling Devices and Systems, UL 2017"

Since we used the word "System Alarm" UL forbid us from labeling it to UL508a... They are claiming any indicator Lamp labeled "Alarm" is UL2017..

The system alarm is not required by any Jurisdiction, But for some reason they think any lamp labeled alarm must be attached to the fire panel.. I have no Idea why we need the alarm company to know a conveyor motor tripped? We removed the indicator light and have it on the HMI only now and all is OK.
Thanks, but that doesn't make sense to me. There are many process/Mechanical packages in the plant that have their own UCP (Unit Control Panel) and on the UCP there are many alarm in the form of indicating lamp and it doesn't make sense to link those alarms to UL2017 .
Who make a judgement on which "system alarms" are categorised as "general alarm" or an "Emergency alarm" ?
Anyway, thanks for the respond
 

Macbeth

Member
Location
Livonia NY
Occupation
Automation
Thanks, but that doesn't make sense to me. There are many process/Mechanical packages in the plant that have their own UCP (Unit Control Panel) and on the UCP there are many alarm in the form of indicating lamp and it doesn't make sense to link those alarms to UL2017 .
Who make a judgement on which "system alarms" are categorised as "general alarm" or an "Emergency alarm" ?
Anyway, thanks for the respond
I agree 110% makes no sense. To them "Alarm" is indicator Lamp (Just told me that yesterday) the Issue they had was its was remote from the equipment, they had no problem with the lights on the control panels. Another time they (New Inspector) had issues with our E-stop on the control sighting 1.18 claiming if it was for Emergency Control to stop the machine the panel could not be UL508a and had to be a UL2017 control panel. It was real funny when we showed them 66.11 requiring the E-Stop. It was like watching a computer "Blue Screen".

In a new situation this week with UL508a folks, they are elevating our customers requirements to 2075/2017 while the International/National Standard Board that oversees this industry (US) list the control system as needing to be UL 61010.
They never talked to our customer or reviewed the site. We had no Idea the UL508a inspector could specify our customer requirements. We though that was left up to the Municipality to deem the need for Life Safety Systems.
Also environment we are in are somewhat harsh and finding UL2075 components is proving difficult.
Unfortunately there is no path around an inspector. They have 100% final word even if they are wrong.
So currently I can not supply to my customer a UL508a panel but my competetres can.

We are currently discussing cost with ETL to switch labels..
 

Jraef

Moderator, OTD
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
...just a 3ph 380VAC feeding Siemens VFDs
You do hopefully understand that we do not have 380V here, right? Please don't do that to someone...

They will not be able to get replacement parts, motors, ANYTHING. It's also unlikely that you will find 380V components that are UL listed, because again, that voltage is not used in places where UL listing is required. MAYBE the Siemens drives, if you buy 480V drives that are properly sized for the 380V motors, but everything else will be a nightmare for someone.

In addition, the panel assembly must have what is called an "SCCR" (Short Circuit Current Rating) on it showing the MAXIMUM available fault current it can handle, which must be higher than what is available at the site where it is installed. Please do NOT simple use the "default" level of 5kA, because that is nearly impossible to comply with in the field.

I strongly suggest involving a UL508A listed control panel builder to handle these issues for you because you seem only peripherally informed about this.
 
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