(small) Industrial Control Panel plan level of detail

[xguard]

I'm designing a small 6 relay panel for a couple of fractional horsepower motors. I'm considering it an "Industrial Control Panel". I'm curious about the level of detail shown in the plans that's normally provided to a UL panel shop to build the panel. This is my first project with a control panel of this sort.

As I'm not a UL panel shop, is it reasonable for me to provide a control schematic, basic interior and exterior layout, enclosure dimensions, primary components list and basically say "fill in any remaining engineering and build this to comply with UL508a"?

If it's not reasonable and I need to fully design every detail of this thing, that's fine, just gonna take a whole lot more time, thanks for any feedback.

 

[Jraef]

I'm designing a small 6 relay panel for a couple of fractional horsepower motors. I'm considering it an "Industrial Control Panel". I'm curious about the level of detail shown in the plans that's normally provided to a UL panel shop to build the panel. This is my first project with a control panel of this sort.

As I'm not a UL panel shop, is it reasonable for me to provide a control schematic, basic interior and exterior layout, enclosure dimensions, primary components list and basically say "fill in any remaining engineering and build this to comply with UL508a"?

If it's not reasonable and I need to fully design every detail of this thing, that's fine, just gonna take a whole lot more time, thanks for any feedback.

If (as I understood your question) you are giving this to a UL508A shop, then don't bother with the layout / placement details, that will be dictated by UL anyway because of fill, wire bending space, separation etc. They should be able to do it with a basic description of operation, or if you want to take system responsibility, you can give them a schematic of your own. Just be aware that if something doesn't work right, they may or may not accept any responsibility.

As to a list of components, only do it if you care. For them, they can use any UL LISTED component, but if the component is only UL Recognized (backward UR), then they have an added expense for UL to evaluate how it is used. A classic example of that is "ice cube" relays. In most cases, the relays are not UL "Listed", they are UR, as are the sockets they plug into. So you can only plug a UR relay into the SPECIFIC UR labeled socket it is recognized to work with and vice versa. So if for example you say "Use an Idec RR2 relay" and that shop has never before used an Idec RR2 relay, they will have to pay UL to "evaluate" the relay and socket. It's not a big deal, but it does add cost. So if you don't care, just say "2PST plug-in relay, 120VAC coil" and let them use what they already have approved. The same is true for most terminal blocks too. Bigger stand-alone things like motor starters, contactors, breakers etc. are usually UL listed so that doesn't apply, and if there is some very specific device you need in the panel, then just let them know by saying "No Sub".

 

[petersonra]

If (as I understood your question) you are giving this to a UL508A shop, then don't bother with the layout / placement details, that will be dictated by UL anyway because of fill, wire bending space, separation etc. They should be able to do it with a basic description of operation, or if you want to take system responsibility, you can give them a schematic of your own. Just be aware that if something doesn't work right, they may or may not accept any responsibility.

As to a list of components, only do it if you care. For them, they can use any UL LISTED component, but if the component is only UL Recognized (backward UR), then they have an added expense for UL to evaluate how it is used. A classic example of that is "ice cube" relays. In most cases, the relays are not UL "Listed", they are UR, as are the sockets they plug into. So you can only plug a UR relay into the SPECIFIC UR labeled socket it is recognized to work with and vice versa. So if for example you say "Use an Idec RR2 relay" and that shop has never before used an Idec RR2 relay, they will have to pay UL to "evaluate" the relay and socket. It's not a big deal, but it does add cost. So if you don't care, just say "2PST plug-in relay, 120VAC coil" and let them use what they already have approved. The same is true for most terminal blocks too. Bigger stand-alone things like motor starters, contactors, breakers etc. are usually UL listed so that doesn't apply, and if there is some very specific device you need in the panel, then just let them know by saying "No Sub".

just because something is listed does not mean it can be used in a UL508a control panel. Only components that are covered in one of the annexes are allowed. some of these components are listed, others are only recognized. But if it is not in the list of allowed components, it has to be added to the shop's procedure, although there are some provisions for using unapproved components components in limited energy circuits.

you can use any brand you want if it is covered in the table. some things the table will say it can be used if it is added to your procedure. I do not really understand why they do this, but as best I can tell if you ask them and pay them, they will add these kind of things without much trouble or expense.

other things truly require more evaluation and that gets very pricey.

your best bet is to send them a sketch of what you want and ask them to make a drawing as part of the deal. it will greatly simplify things. most shops have deals where they buy larger quantities of certain brands of parts and get substantial price breaks. it might cost $100 for an AB IEC starter while they can get the equivalent ABB unit for $40. unless you really care one way or the other, best to let them select the parts.