electronics question

Hey guys, I have a drive that I am trying to get a fault signal out of. What I need to do is when the drive faults, I need to open a set of contacts which will be placed in the Estop rung to shut everything down when there is a drive fault.

The fault output pin description reads like this:

This is a composite output signal which goes high in the event of an overload, short circuit, supply failure, or overtemp fault. It is driven by an open collector transistor and should therefore be pulled high by an external resistor when the signal is required. The resistor should be returned to a voltage not higher than + or - 30V and should not permit more than 15mA to flow when the output is low.

Reading this, I get nothing out of it. Can anyone explain to me in simple terms what I need to do to accomplish what I want? Any input is helpful. Thanks.

Russ

The resistor should be returned to a voltage not higher than + or - 30V

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This sounds a bit strange, however since they mention that current flows when the output is LOW, I'll assume that it should be max + 30V.
More likely you'll have a 24 VDC supply. If you can source a 24VDC relay with coil resistance of 2k or higher, then connect this between +24 and the open collector output. Connect 24V common to the drive's output common. Place a free-wheeling diode in parallel with the coil (cathode to +24). From the description, the relay would be normally energised, dropping out on fault.

Gerry's suggestion sounds like it should work. The relay coil will act as the pullup resistor.

What brand/model is the drive? Is the manual available online?



-Eric

Eric Nelson said:

What brand/model is the drive? Is the manual available online?

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Nevermind, I found it (Gotta love Google!). Fancy diagrams for motor connections, but NOTHING for the I/O lines...

So again, Gerry's suggestion sounds fine.

Oh yeah... The manual is HERE.



-Eric

Be sure to use a safety relay when using it in a E-stop circuit. At least that would be necessary in with us, I'm not sure about US.

Gr.
Heino

Eric Nelson said:

Nevermind, I found it (Gotta love Google!). Fancy diagrams for motor connections, but NOTHING for the I/O lines...

So again, Gerry's suggestion sounds fine.

Oh yeah... The manual is HERE.



-Eric

Click to expand...

Eric, what bits of info from Russ' post did you use for search criteria? Or are you psychic?

Gerry said:

Eric, what bits of info from Russ' post did you use for search criteria? Or are you psychic?

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I'm psychic...

Thankfully, Russ posted the text from the manual verbatim. I just copied a bit of it and posted it into Google. Surround it with quotes, and Google will look for that 'phrase'.

It's important to select a search phrase that won't be too common. You wouldn't want to look for "open collector transistor". There's a good chance that combination of words has been written by a few different people. Turns out that 5680 pages contain that phrase. I used "composite output signal which goes high" (WITH the quotation marks) as the search. I doubt more than a few people have put that exact combination of words together in that order. Bingo! One hit...



-Eric

You guys are awesome! I completely forgot to put the make and model of the drive down, but yes, this is pretty much the manual. According to the manual I have though, I have only a 5 volt supply, and there is a drawing of the circuit described. There are already resistors shown in the diagram, so I am confused a bit. I am unsure if they are already in place, or if I need to add them. I don't have the liberty of shutting down the machine to open the drive to find out, so I need a game plan before I go tinkering.

Russ

Russ,

A diagram of the fault circuit is shown on page 26 of your manual. The resistors shown are internal. You need to add a resistance, not necessarily a resistor as the manual states. This is probably a translation error. (Many technical manuals are written originally in other languages then translated to English). The Fault output, Pin #2, comes from the Collector of an NPN transistor, with the Emitter already connected to 0 VDC, and the trip signal is wired to the Base.

I suggest that you wire your +5 VDC (in your case), available on Pin 1, to the + terminal of a 6 VDC relay coil, then wire the negative terminal of the relay coil back to the Fault output on Pin #2. Then you can use the relay contacts (probably an NO) as needed to break you E-stop circuit.

Eric Nelson said:

Fancy diagrams for motor connections, but NOTHING for the I/O lines...

Click to expand...

Then...

Lancie1 said:

A diagram of the fault circuit is shown on page 26 of your manual

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Indeed there is! I didn't read that far...



-Eric

Lance1 has given you good advice about how to connect a relay to the output but you are going to have a hard time finding a 5 or 6 VDC relay which draws 15 mA or less. I would recommend you connect a Solid State Relay as Lance1 has described and have the SSR drive a normal 120 VAC relay.

I have seen that description of the failt circuit in an early Toshiba drive. If you are only using the fault to stop the process by dropping out the E stop Circuit and the system is designed so that operators cant treat this stoppage as a safety-lockout then I dont think a safety relay is required. However say if the EStop safety circuit being off allows access gates to open etc then what you are doing is a no no.
Regards Alan

What! No 6 volt relays! I remember when all cars had 6 volt batteries. Then you could get all kinds of 6 volt relays.

Lancie1 said:

What! No 6 volt relays! I remember when all cars had 6 volt batteries. Then you could get all kinds of 6 volt relays.

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God we are old, my second car was a 56 Ford Crown Victoria that had a 6 volt system...gave $50 for that thing and loved it, on the hiway the Chevy's didnt have a chance.

First, thanks for all the help guys. I am not sharp on this sort of thing. I am the kind of guy who wants a simple fault contact coming out of the drive to work with. I believe I have a plan in place, but only have one question. Internally, there is a +5 VDC that is supplied to the reset terminal #7. I measured +5 from pin 7 to pin 8, 0V. I have decided to use a 12VDC system, as this is already available via power supply on the equipment, and 12VDC relays are a stock item here and readily available while 5VDC are not. I plan to take 12VDC to 12V relay. Coming out of 12V relay wired to pin 2, fault pin, which is the collector of the transistor output. The emitter is then tied to 0V, pin 8. My question is, do I need to connect the 0V of my 12VDC supply to pin 8 as well? It seems to me that I should, but I am reluctant to do so knowing that pin 8 is also the 0V for the internal 5VDC supply. Does this matter, or is my fear unwarranted. Thanks again for all the help thus far.

Russ