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Thread: DDC panels

  1. #1
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    Hmm DDC panels

    Hello i have one question how do we define the best DDC panel generally?
    any tips that solves many problems from the very start?

  2. #2
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    Your question does not make sense to me.

    Are you asking the best DDC manufacturer? The best designed DDC panel?
    Other?
    "How it can be considered "Open" is beyond me. Calling it "voyeur-ed" would be more accurate." pka LeroyMac, SkyIsBlue, fka Freddy-B, Mongo, IndyBlue
    BIG Government = More Dependents
    "Any 'standard' would be great if it didn't get bastardised by corporate self interest." MatrixTransform
    http://threedevilskennel.com/ - not my website.
    Versatile Hunting Dog Federation - www.vhdf.org/


  3. #3
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    Well sorry English is not my native sometimes i do make some mistakes
    I would like to ask when you are designing a DDC panel which points,details are very important?I am a new engineer at this business i have so much to learn and i do not want to miss details
    Thanks anyway

  4. #4
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    What kind of equipments that you control? All the points in DDC are all important.
    Better look at the specification of the project. In the specification it will guard you to design the DDC panel.

  5. #5
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    I will work in moscow city project when my visa is done.According to my friend who worked there before me
    Some DDC panels comes without anything no cable tray,no transformer
    there was a project yeah but i may need to add few things.there we will use siemens equipments(PX series) and we will control pumps,dampers,AHU's
    btw thank you for your interest

  6. #6
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    I have to ask.....

    Are you looking for control design suggestions (control engineering)......

    OR........

    Are you looking for Control Panel component layout design suggestions ?

    2 very different things.

    Can you be more specfic so we can possibly assist you ?
    If sense were so common everyone would have it !

    All opinions expressed are my own. Any advice provided is based on personal experience, generally accepted fact or publicly available information. As such, it is worth exactly what you paid for it, not a penny more not a penny less !!

  7. #7
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    Quote Originally Posted by CCIKelly View Post
    I have to ask.....

    Are you looking for control design suggestions (control engineering)......

    OR........

    Are you looking for Control Panel component layout design suggestions ?

    2 very different things.

    Can you be more specfic so we can possibly assist you ?
    Actually my problem is the second one
    but also i am very interested in the first one too
    Thank you for your kind interest

  8. #8
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    - Mount the largest piece of wiring duct where you suspect most of you wiring will come in at. Then mount a second piece the same size perpendicular to that. Generally most of the penetrations come in the top so a large piece at the top and another large piece along the right/left edge. Then mount smaller pieces everywhere else. This is so you have a large main route for most of the wires to pass through.

    - If you use terminal strips so most of the panel can be built in the shop vs. in the field then mount the terminal strip just above/below the largest piece of the wiring duct. Again if most wires will enter/exit through the top then mount your wiring duct at the top and then just below that do the terminal strip.

    - LEAVE A WIRING DIAGRAM IN THE PANEL. I like to see them taped/glued on the inside cover of the panel, especially when using a hinged panel and I like it even more when it is laminated. But even just left in the panel is better than nothing.

    - If you don't have a terminal block for everything in the panel then make sure you leave extra wire in the wiring duct. When installing you'll find you need to move wires, points change or get wired wrong. If you leave extra wire then you don't have to splice.

    - Don't be afraid to use over-sized wiring duct. When wiring duct starts to become too full you will wish you had used a larger size.
    "How it can be considered "Open" is beyond me. Calling it "voyeur-ed" would be more accurate." pka LeroyMac, SkyIsBlue, fka Freddy-B, Mongo, IndyBlue
    BIG Government = More Dependents
    "Any 'standard' would be great if it didn't get bastardised by corporate self interest." MatrixTransform
    http://threedevilskennel.com/ - not my website.
    Versatile Hunting Dog Federation - www.vhdf.org/


  9. #9
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    1. Large wiring duct
    2. Separate Transformer power
    3. Separate IN/OUTS and multiple controllers

    Personally, I always used terminals and the smallest relays I could find. Typically I used those AB relays that looked like a terminal block.
    I'd label all terminals and leave a wire duct above so when cables came into the panel I could keep the mess in the wire duct and terminate to the terminals.

    Also, later on I'd use power supplies (like BAPI) to separate loads and fuse things separately. Incoming power went to a power switch and an outlet for the occasional PC or other connection as necessary.

    Regards cabling, I had some standards. If bringing in a three wire from a valve - Red+ Blk- and Signal the next color (typically white). If I had feedback that's green (typical next conductor color) Anyway, it was very easy to see how a panel was structured. For internal wiring from controllers to blocks we used colored 16ga and kept colors according to a standard. OA sensor would be two yellows to the controller, SATemp would be blues.... you could follow things relatively easily.

    Having the terminal blocks also allowed me to insert the panel later after rough in. Further you can bench test in advance so to me the cost was not an issue.

    I always tried to keep the connections on top or a couple horizontal rows. However typically there is more distance vertically for terminal blocks and you can bring in connections right and left. So, you really need to use something like Visio or CAD and insert the components to double check your fit. Well worth the time because always you want the biggest wire duct possible for incoming cable.

    And of course a couple things to keep in mind:
    The panel typically is never big enough.
    Always add extra terminals just in case.

  10. #10
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    pick the largest panel you think you will need and go one size bigger.
    there is never enough room.

    use a power supply with built in 110 outlet and switches and breakers for both line voltage and control voltage, saves alot of room
    http://hvac.functionaldevices.com/ch...rSupplies.html

    label the wires with a sharpie or tag. i prefer a sharpie, tags fall off.if you have to move terminations around you will be glad you marked the wire.
    right mike ?

    i always tried to keep my panels consistent. in both the labeling and layout. it makes it easier for your service guys.

    if you leave a wiring diagram in the panel it will disapear. i print the AS BUILT diagram out on a peel and stick label and stick it to the door.

    as already stated try to develop a color scheme for your wiring (red hot, white common) etc. and be consistent.

    if you need to tie a bunch of hot or commons together use a terminal strip. don't put a bunch of wires in a wire nut and stash it in the the wire duct.

    be cautious about which relays have hand off auto switches. i never liked putting HOA's on compressor or burner relays. people switch them on and forget to turn them off.

    seperate the line voltage from the control voltage. mark the line voltage. it keeps guys from curling their hair.
    IV IV IX

    use your head for something other than a hat rack.......Gerry

  11. #11
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    Quote Originally Posted by Arvedui View Post
    Hello i have one question how do we define the best DDC panel generally?
    any tips that solves many problems from the very start?
    As to the panel itself, I have no particular recommendations. Panels are available from many sources, in many styles and colors. I personally prefer a clean, simple, well made utilitarian design as versus something that makes an attempt to look stylish and fancy. And prefer a line of panels that are available in a variety of sizes while having an identical appearance and style.

    To me, it looks more professional, more planned and thought out as versus just hacked together willy-nilly as one does the installation, and it makes identifying and finding things later easier for service guys, etc. i.e. When I walk into a machinery room with controls our guys put in I can locate OUR panels immediately as versus anything else.

    We also have an attractive label with our company logo, name, service phone number, etc on each cabinet. Self sticking style; glossy, waterproof front. With added labeling in sizable, bold font stating what's in the panel and what it controls. i.e. TAC Vista Controller, AHU #2, etc.

    On the inside of the cover, we install an adhesive backed clear plastic document pouch (available from any office supply place. A thick, sturdy one. Inserted into it is a controller points (I/O) listing, for quick reference. Which gives pertinent data as to type of controller, network ID if applicable, when installed and by whom, and some other info such as the date powered up and commissioned. All at the top. Below that some columns. One row for each input, analog output, and digital output. First column indicating the I/O point, second giving a plain English noun name for what is connected to that I/O point (abbreviations sometimes used but ONLY when they're commonly known and used), next column listing type of device (dry contact, resistance, thermistor, 4-20 ma, etc), next column showing range/scaling, a column to indicate location (room number, or "on AHU", etc), and then a column with the initials of the person who checked and commissioned the point (the full name being on the top of the page).

    This is a handy and quick reference for someone troubleshooting.

    Tucked behind this is a page or pages as the case may be, with the actual wiring schematics, system layout drawing.

    The idea being to both look professional and to make later troubleshooting or system mods/additions easier for whomever is doing it. Our service guys love it.

    As to sizing such panels. There is much debate about this.

    In our case, we decided upon 3 "standard" panels. A small, a medium, and a large. This was to simplify ordering and stocking, and to allow us to take advantage of quantity discounts from the maker.

    An additional benefit is that our installers over time have learned the dimensions, how to work with them, how to quickly estimate installation spacing requirements, figure out what incidental installation materials are needed, etc. i.e. In one project, we needed to install several panels on one wall area in a machinery room. It was 3 rows of 3 panels and there were reasons for our needing to do it that way. Our installer was so familiar with the panel dimensions, spacing required to get in the gutters and required conduit bends that he worked out the precise layout of everything in very short order, as well as what went in first, then second, and so forth so that the actual install went smoothly, quickly and looked sharp and professional when he was done.

    Consider panel location. Whenever possible we try to get panels into a spot that makes both the installation of it and its components and later service work as easy as practical. Panels chest high is ideal; located in machinery rooms, electrical or network closets, janitorial supply/work rooms, or storerooms is best. But not always possible.

    Easy to work on, out of the way so a tech doesn't get in the way of occupant traffic.

    But sometimes you have to locate one elsewhere. Such as above the ceiling tiles. If we have to do this, and we often do, some thought is given to it beforehand. We attempt to NOT place panels above ceiling tiles within a room normally occupied by folks who'll be disturbed by a tech working on something. If such would be the case, if it is possible, the panel is located above the ceiling tiles out in a hallway, vestibule, or whatever just outside the room.

    BUT ... never, unless unavoidable, over a doorway, in the middle of normal walking traffic, etc.

    In short, we always, always consider panel accessibility at a later time after the building is normally occupied.

    Now, I've had some folks in the past suggest that placing ALL panels in some central area (or within a couple such areas) that is large enough to hold them, is the way to go.

    For instance, on one project years ago I had an installer insist upon putting all the controllers (except VAV controllers, and those associated with the building's main boiler room) and panels for the whole building into two penthouse machinery rooms. Which were very roomy, with lots and lots of available wall space. So we ended up with something like 20 panels in each of two penthouse spaces. Seemed like a good idea. Installation looked nice. Panels were easy to access.

    BUT ... troubleshooting/servicing was horrible. Controller for a FCU located at a loading dock was 250 foot away and up on the roof of a 3 story building. So, for instance, you might check a connection at the controller terminations point, then have to travel a ways to go check termination at the fan start relay, damper actuator, etc. Do this numerous times for various things and yah get sore legs from all the stair climbing and walking, and that's not mentioning the extra time wasted.

    Add, I like to issue commands/overrides to the controller when troubleshooting, to do something like cycle a damper, and then be able to SEE the damper respond correctly. I don't trust what the controller is saying (or the front end) until I've sight verified that the info is true and correct.

    In my example case, my options would be, since there was no local network connection, to either do a heck of a lot of back and forth running, or to have a second guy working with me. One of us issuing commands, one to observe actual equipment movement/response.

    And none of this mentions the other problem. The long, long runs of large bundles of cables. And all the problems that is. To install, to replace a bad cable, and to troubleshoot.

    I kicked myself in the a** for allowing that installer to override my better judgment. And haven't allowed it since.

    Now, whenever possible, panels and controller are distributed and placed as close to the equipment they control as practical. With the only long runs being network wiring.

    Side benefit to this, if a breaker or power panel that supplies the control transformers pops, goes down, or is put out of service for whatever reason; only one or some of the controllers die. Other things continue to work.

    That's IAW our general philosophy in the first place. As much as is practical we utilize controllers that are or can be "stand-alone". That is, if the network cable is cut or whatever, the controller just keeps on doing what it is supposed to do. Likewise we tend to use controllers with smaller I/O counts when practical and have them specialized.

    i.e. In a particular installation I could have used a controller which could have additional IO modules added to it so as to bring the total of all IO points up to a count so that the one controller could have controlled a large number and variety of equipment. As an example, a wing of a school which had a total of 20 classrooms. Each classroom needing occupancy lighting control, control of a supply air damper, and control of a reheat coil valve. I could have simply used one controller with IO expansion modules adequate to handle all the points. But then if that one controller died, the entire wing suffered. A whole wing going cold and dark in a Minnesota winter is generally not a good idea.

    Instead I planned for 3 rooms per a smaller controller. Plus one controller which only handled 2 rooms. Its called damage control. One controller dies, only 3 rooms are affected. And someone can throw open the doors to allow warm air from other rooms and the hallway to keep the temps inside the rooms bearable, or at least keep stuff from freezing. Or have to temporarily relocate only 3 rooms of students to a cafeteria, auditorium, or whatever as versus 20 rooms of students.

    Just something to consider. Thinking about panels involves more than just style and size and layout of the panel itself.

    As concerns panel layout.

    I read that you've already gotten a lot of good advice. Not much for me to add that's new. But I have a few comments.

    Plan on using roomy panels. It has already been said, but I'll repeat it. Yes, such cost more. BUT, you'll make up on the additional cost in time saved installing the stuff in the first place. In any given year, our temperature controls department alone installs several hundred panels, usually coming close to a 1000 and sometimes exceeding that number. I know from both talking to our installers and observing them that their work in wiring and terminating goes far faster when they have room to get thick bundles of conductors and thick fingers into the box. AND ... as a guy who does the testing and commissioning (as well as programming, occasional engineering, or whatever else needs to be done) I've noted that they make fewer mistakes when working in roomy panels as compared to working in cramped spaces.

    Needless to say later testing, commissioning, troubleshooting, fixing, adding point connections, etc is also faster and easier.

    Saving a few dollars on a smaller panel that results in a cramped install is never worth it. Not ever.

    Plan on not only adequate height and width, but depth suitable for the components you normally use, plus a bit just in case.

    I tend to favor cable track use within a panel as versus just running in the cables and then tying them into neat bundles with cable ties. Cable track looks neater, but is also easier to work with when troubleshooting or making changes. Just snap off the cover and follow the wires. Or lay in another. Use larger track than you think you need. This allows easier additions and the ability to leave some extra length of cable/conductor inside, tucked out of the way but available. Cutting a conductor to just the right length to reach terminal A on that controller ... is a bad idea. At some point you may decide to change which IO that cable is connected to, or may have to snip an end to get to some a new clean and non-frayed bit of copper then remake the connection, or whatever. Some extra end-of-cable length is always desirable.

    If not using track, still have installers leave extra lenght and have it all laid out as neatly as possible and nylon tied down.

    Label EVERYTHING. Each conductor and each component. Looks professional and will save you no end of trouble later when troubleshooting or making changes.

    Make labeling obvious. Wire "1", "2", "3" ... sucks. "DAT", MAT", "AHU S/S", etc is much better. Our installers have pro grade hand held label machines to use. But we also provide them with sheets of pre-printed, standard labels. So they don't have to take the time to hand print everything. i.e. "DAT", "MAT", and so forth. I carry a machine that can hook up to my laptop from a label machine, with software so that I can easily and quickly call up "CO2 Sensor", for instance, and print as many copies as I select. Quickly, and on the spot. All selections for orientation, font, etc already made and stored for recall.

    Installers get em for not only labeling in a panel, but put them on the other end of the cables at a sensor, actuator, relay or whatever. And stick a label on the outside of a device to indicate what it is.

    I like terminal strips. I don't insist upon them, but like them. Particularly for the control power connections.

    Speaking of control power, we prefer transformers with their own circuit breakers. Yep, they cost a little more, but the added safety plus the ease of just resetting one as versus replacing one makes up for it. Also a means provided for easily and quickly disconnecting both the high voltage side and the low voltage side. Some folks use switches, that's fine. We've started using those polarized quick disconnect fittings that many electricians now use on lighting. Fast, easy to install and use, cheap. You can only connect them one way. This also makes replacing a control transformer a snap. You haven't even got to go find and trip the supply breaker.

    Relays and other components. We standardize those as much as practical. For instance, the cube relays we use are all Omron, using the same bases (for those with the same number of poles). I'm not saying Omron is the only and best choice, its just ours. The point being that our installers know from memory the connection layout of the Omrons, how much space each will need, and what size of din rail to use. 1-2-3 they KNOW it, no fumbling around, VERY few wiring mistakes. The standardization also means fewer different kinds of spares are needed to be on hand. For situations requiring them, where a relay in a box is appropriate, we use RIBs. Period. Same principle as with the cube relays. Installers have wire color codes memorized, spacing requirements, hole size, etc.

    We always opt to use relays with "relay energized" LED's. For ease of troubleshooting. And as a standard, lighted LED indicates device Start/Stop or On/Off command present, or "Safeties OKAY". IOW, no light means system either not ordering thing to energize, start, or open; or a safety is tripped; or you have a wiring problem or the relay itself is bad.

    HAO. We try to provide HAO whereever practical and safe. Most controllers we use have built-in HAO switches on the binary outputs. But if not, we put something in where needed and reasonable. However, if there are safety circuits that are involved which may be tripped ... HAO will not work on hand unless safety condition is cleared first, or a separate switch is provided that's labeled "Safety Override ... use at your own risk" that must also be operated.

    If panel is going to get very crowded and larger single panel is not practical, we'll normally opt to add a second panel that will contain pilot relays, separate DC power supplies, pressure transmitters or other items and just have the controller itself in its own panel.

    Just some things to think about. I'm certainly not saying I have all the best or right answers.
    A site where I stash some stuff that might be interesting to some folks.
    http://cid-0554c074ec47c396.office.l...e.aspx/.Public

  12. #12
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    Guys many thanks for the information
    i wanted to kiss all of you but after 5 seconds i say "ca'mon let's forget about it"
    Thanks)))

  13. #13
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    Quote Originally Posted by Arvedui View Post
    i wanted to kiss all of you but after 5 seconds i say "ca'mon let's forget about it"
    Thanks)))

    Not sure where you are from but given this field is mainly made up of males - Guys kissing guys in America is just not a good thing! But if you happen to be a good looking gal....
    "How it can be considered "Open" is beyond me. Calling it "voyeur-ed" would be more accurate." pka LeroyMac, SkyIsBlue, fka Freddy-B, Mongo, IndyBlue
    BIG Government = More Dependents
    "Any 'standard' would be great if it didn't get bastardised by corporate self interest." MatrixTransform
    http://threedevilskennel.com/ - not my website.
    Versatile Hunting Dog Federation - www.vhdf.org/


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