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  1. Transitioning to Logix5000

    Ya... "find all" is worthless in RS5000. In 500, it shows you everywhere a tag is used, in 5000 you have to use 'cross reference' to see that.
  2. Protection for Electrical Heater

    If you are using single phase power (which a single element heater is... there are multi-element arrays of heaters that accept 3 phase power at their pigtails, but let's assume you're not using that)... so if you're using single phase power, and one of the legs is neutralized (bonded to ground at the supply transformer), then THAT leg and only that leg can be connected to the heater at all times. If you are using 3 phase power, and just pulling 2 legs off of a 3 phase 480 line, and then feeding that 2 legs into a heater, and neither of those legs are bonded to ground, then it may not be a code violation (it may or may not, I'm not sure off the top of my head), but it's bad practice for sure. Anyway... thermal (or electro-magnetic variety) overloads have inverse time characteristics, but so do plain old circuit breakers. Basically, it's a trip curve - a relation of instantaneous current draw versus time that let's you predict at what current and what time that current is held for that a breaker / fuse / overload / or any other device will trip out. Straight thermal overloads will require that they cool off before they can be reset - they physically won't stay held in until they cool off after a trip. They're older technology and generally cheaper. Electro-magnetic overload units are direct replacements for thermal overloads (and we still call them "overloads" or "thermals" or "heaters", because they're doing the same job), but can be reset immediately after a trip, and generally cost two to three times as much. For a 3 horse motor running on an appropriately sized IEC din rail starter, a thermal overload might run you 15 to 25 dollars, whereas a electro-magnetic one might be 50 to 100 dollars, which will vary widely based on manufacturer and ratings, but that's a general ballpark. The thermals also have a limited lifespan - you can only crap them out so many times (a lot of times, but still it's limited) before they're shot. Electro-magnetic ones have lifespans of 50 to 100 times that -- basically, they'll only go bad if they're defective (usually). To specifically answer your question... heaters are purely resistive devices - not inductive. So your overload factor can be dang near zero. Most overloads, right out of the box, will trip at 125 percent of their dial setting. So will this protect your solid state relay? Yes. At least if you size the SSR's correctly. If you're going to run 10 amps typical draw on a single heater, then you should use an SSR with a nominal current carrying capability of no less than 125% of 10 amps (which would be 12 and a half amps). When the heater starts to go bad, it'll increase amperage draw, and the overload will trip... the SSR will still be in its nominal operating range. If you see a dead short, the breaker will trip. Everything must be sized appropariately, this goes without saying. Here's one example XFMR --> C breaker (5 to 10X nameplate trip) @ 150% typical heater draw --> contactor+overload @ 125% typical heater draw --> SSR @ 125% typical heater draw --> heater XFMR --> 15 amp breaker --> 10 amp contactor with 10 amp overload setting (will cut out at sustained 12.5 amp) --> SSR @ 12.5 amp or better --> 10 amp heater ... use 14 awg THHN, MTW, or THWN conductors. You're never going to (at least not without a lot of wasted time and money) protect a 10 amp SSR from the failure of a 10 amp heater, but you can protect an over-rated one from it.
  3. Output card for motor starters

    When did control power conductors become required to be color coded per NEC ? (unless this is something new, I strongly disagree - I'm not saying it's a bad idea, but there's no requirement that I'm aware of as of 2008 NEC).
  4. just a bump here, and an update. about 2 months after it cropped up, it transitioned back to me - such is life. implementing a plan based on your thoughts as well as some other internet-dwelling psychopaths, i do believe it may be resolved. -- micrologix and slc controllers are tied in via AB-ETH driver -- devices (slc / plc-5 / other) that are accessed via a controllogix chassis bridge (just a ENBT/EN2T card and a DHRIO card in a common chassis) are accessed via the AB-ETH/IP driver -- controllogix processors are accessed via the AB-ETH/IP driver @ispresent not found no longer presents itself. rather, when the controllogix in question, or any other one for that matter, goes offline - rslinx responds with the (appropriate) error "communication lost to device [whatever device]". when the device is restored, communicate resumes shortly thereafter. we'll see how this plays out - but i'm unofficially declaring "tsang tsung - flawless victory" on this one.
  5. Protection for Electrical Heater

    1= without doing any research into the tech, i dont see why not - simply size appropriately. 2 = no 3 = yes 4 = class D breaker or time delay breaker where instantaneous trip is 10 to 15 times nameplate size. break the secondary as well, same breaker type / fuse type. 5 = honestly, i wouldn't bother with any of it. i'd use a 3 phase SSR for the heaters (for fast switching) and then strap contactors with thermal overload decks to them, with the control power for the SSR and the contactor going through the normally closed contacts of the thermal overload deck. no need for burnout detection, as overamperage will show on the overload deck. i also assume you will fuse / break each of these accordingly.
  6. For the moment this issue has been taken out of my hands - there is a belief among some that it is a hardware issue - which is mind boggling when you consider that it occurs when the device in question is --OFFLINE--. Will provide some feedback if/when this ever gets resolved.
  7. Reliance AutoMate to ControlLogix conversion

    The last time I saw this come up in my experience, the head of engineering contracted it out to Rockwell directly. I guess when AB bought out Reliance, they built some Reliance-to-AB conversion software that's extremely effective, and they've supposedly kept it up to date over the years --- so now they're able to do Reliance to Controllogix "like a breeze". Pricetag is probably astro-freakin-nomical though.
  8. L35E Read/Write messaging

    For up to a modest amount (let's say 4 words -- that'd be 8 DINT's [16 bit integers]), I see great success running message enable times of as low as 10 milliseconds. This is on Compact/Control Logix platforms, SLC-505's, and MicroLogix platforms over ethernet. Anything over a serial connection, DataHighway Plus, or through a Net-ENI, I typically will not go any lower than 20 milliseconds.
  9. micrologix 1400 question

    It's a different application, but I did something sort of similar recently - and anytime you're going to jerk a drive like that (I'm changing speeds drastically with no delay), then the easiest way to avoid having to add an appreciable amount of logic is to simply set the accel and decel times on the drive appropriately. For example, if you're slamming a drive from 15 hertz to 80 hertz or anywhere in between - and doing so as much as 10 times per minute, then simply setting the accel time to "2 seconds" (provided it fits your application) can solve any "jerking" issues. It depends on VFD manufacturer, but the ones I used would employ a scaled 2 second delay across min freq / max freq. For example... VFD hard limit min freq = 0 Hz / VFD hard limit max freq = 120 Hz. Accel = 2 sec. Decel = 2 sec. Therefore... ( 2 seconds ) divided by ( 120 Hz - 0 Hz ) = delay of 17 milliseconds per 1 Hertz step. So when ramping from 0 to 80 Hz, it would take 1.33 seconds. / going from 40 hertz to 60 hertz would smooth out over 333 milliseconds. Etc, etc... It's a nice way to cheat, provided you standardize on VFD types (or at least buy VFD's with comparable feature sets / attributes, and be sure to document what your settings are... I make it a point to put large comment rung in a PLC program where the VFD is referenced and place any relevant / critical VFD parameters in there so that the next guy knows what he needs to do if the VFD blows up and he has to replace it).
  10. Contrologix remote rack over ethernet

    ENBT = 128 connections / 64 up and 64 down EN2T = 256 connections / 128 up and 128 down
  11. Installing Panelbuilder 1400e on Virtual Machine (XP Mode) - Having an issue

    That is correct. Running VMWare or VirtualBox on Win7 is fine - both of those environments are solid virtual machines. However the 'built-in' Windows "XP Mode" or "Windows Virtual Machine" environment are beyond poor.
  12. uLogix 1500

    Whoever invented this particular model of death should be subjected to various unlimited forms of torture. Micrologix 1500 supports such great features as: -- cannot do online editing. -- no builtin ethernet interface -- ability to use 1761-NET-ENI for ethernet (wow - 4 whole concurrent connections, how snazzy!) -- embedded I/O (I hate embedded I/O - when I build a small system with an 1100 or 1400, I never use the on-brick I/O, makes emergency I/O card swaps easy). -- CompactLogix add-on I/O modules (really? why? The modules available for the 1100 / 1400 / 1200 are easier to configure, just as good) -- crappier instruction support than any other Micrologix processor. (I don't understand why 1100 / 1200 / 1400 have instruction support more resembling SLC-504 late firmware / SLC-505 than the 1500, which seems as bad as early firmware 503's).
  13. EZ-Touch to C More Conversion

    ... I call them Sleazy Touch panels. "He's got the slow hand... and the Sleazy Touch".
  14. Installing Panelbuilder 1400e on Virtual Machine (XP Mode) - Having an issue

    Windows 7 virtual environments are very poor in quality. You will have success using either VMWare Player (free but not very robust) or Sun (now Oracle) VirtualBox (free OpenSource). I prefer VirtualBox - http://www.virtualbox.org
  15. PLC5 multiple sockets

    PLC-5 has builtin DH+ 2-wire as well. If you don't have an "E" version processor, or you don't want the ethernet side car, then you can get Panelview Plus terminals with the DHRIO addon board. These will talk DH+ to the PLC-5 all day long, and you can have something like 77 (octal ... that's 63 actual [decimal] ) devices total per channel - most PLC-5's have at least 2 DH+ channels.