# Trash Compactors



## Helmut (May 7, 2014)

Does anyone have experience in the controls and safety aspects of these?









Pretty straight forward, except the key isn't a "spring return" type as I would have thought. This way the operator has to have the key turned, in order for the compactor to operate. 

This is not. Turn the key, press the forward button and walk away.

The insurance company spotted this, and wants it fixed. Said someone can jump into the compactor while it was running. The inlet chute has a 48" high rail around it, with a gate that opens in the front. This gate must be closed in order for the compactor to operate.

Should the key switch be changed to spring return?


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## daveEM (Nov 18, 2012)

Of course. That way the operator is there supervising the compacting process.


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## AK_sparky (Aug 13, 2013)

I've never done any trash compactors. Similar equipment we've wired so that the FWD/REV button needs to be held, the key switch would stay the way it is. You still get the desired "operator-present" functionality.


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## macmikeman (Jan 23, 2007)

If somebody want's to jump into a trash compactor, they sorta ought'a be allowed to.


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## wildleg (Apr 12, 2009)

yes .


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## daveEM (Nov 18, 2012)

So messy tho.


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## telsa (May 22, 2015)

macmikeman said:


> If somebody want's to jump into a trash compactor, they sorta ought'a be allowed to.


That's tight. :notworthy:


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## MikeFL (Apr 16, 2016)

The key switch does not operate the compactor. It only enables one to operate it.


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## AK_sparky (Aug 13, 2013)

MikeFL said:


> The key switch does not operate the compactor. It only enables one to operate it.


If it doesn't operate momentarily as MikeFL suggested, I would remove the latching portion of the circuit to make it operate that way.

Actually, looking at it again, there is no STOP button, so I doubt it just continues to run once you hit FWD. Have you actually tried to operate the compactor to see how it currently functions?


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## Helmut (May 7, 2014)

AK_sparky said:


> If it doesn't operate momentarily as MikeFL suggested, I would remove the latching portion of the circuit to make it operate that way.
> 
> Actually, looking at it again, there is no STOP button, so I doubt it just continues to run once you hit FWD. Have you actually tried to operate the compactor to see how it currently functions?


Nah, Just got this email last night


"Hey buddy, how have you been. I need a quote on some work. Our trash compactor as its wired now you put a key in, turn it on then press start button and it runs its compactor cycle, insurance company believes this is unsafe as the operator could then go in the dumpster while its running (because that’s what everyone thinks to do, jump in a running compactor) but any way they recommend having a switch that requires the operator to hold the button the entire time until it completes its cycle, so I guess a momentary push button instead, here’s pic of controls, guess you would have to look at wiring though. Let me know what you think."


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## AK_sparky (Aug 13, 2013)

Helmut said:


> Nah, Just got this email last night
> 
> 
> "Hey buddy, how have you been. I need a quote on some work. Our trash compactor as its wired now you put a key in, turn it on then press start button and it runs its compactor cycle, insurance company believes this is unsafe as the operator could then go in the dumpster while its running (because that’s what everyone thinks to do, jump in a running compactor) but any way they recommend having a switch that requires the operator to hold the button the entire time until it completes its cycle, so I guess a momentary push button instead, here’s pic of controls, guess you would have to look at wiring though. Let me know what you think."



Sounds like you could probably easily convert it to require it to be held. Let us know how you make out.


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## inetdog (Apr 13, 2016)

macmikeman said:


> If somebody want's to jump into a trash compactor, they sorta ought'a be allowed to.


No! 
That would be introducing bio-hazard waste into the normal waste stream.

Sent from my XT1585 using Tapatalk


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## splatz (May 23, 2015)

I'd say the keyswitch is fine if both of the switches are momentary, or better yet a spdt momentary switch with center position off. 

I think this one might do the right thing...

https://www.wolfautomation.com/selector-switch-black-21392

or

http://www.alliedelec.com/idec-corporation-cw1s-33/70792640/

from 
https://www.idec.com/language/english/catalog/Switches/CW_Brochure.pdf


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## Helmut (May 7, 2014)

AK_sparky said:


> Sounds like you could probably easily convert it to require it to be held. Let us know how you make out.


Check this out..

In the photo, the middle button is STOP, bottom button is REVERSE.

Here's what I know now. Theory of op as I can tell.

Turn the key and the hydraulic motor starts and the ram starts travelling to compact. Let go of the key before the first 5 seconds, and the motor and ram stop. After 5 seconds, you can turn the key to off and pull the key out, and the compactor will run a full compact cycle.

Press the stop at any time, with key in and turned, or while compactor is running, and the unit stops. 

Turn the key, and press REVERSE, and the ram comes out.

---------------------------------------------------------------------------------

My best guess, without digging in to it, and why the key comes out, is this.

There must be limit switches mounted under the dock deck, that detects where the ram starts, and ends. Kinda of a no brainer.

The 5 second thing, must have to do with one of these limit switches. It appears that this is close to the time the ram takes to go from fully open, to just past the entrance of the container. 

You have to hold the key turned, until the ram is into the container, or so it seems. Maybe this is the manufacturers way of trying to prevent operators from falling in and getting crushed when it compacts. Coupled with the gate, I'm can't see how someone could fall in, but I'm sure there is an idiot out there that will find a way.


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## Helmut (May 7, 2014)

Thinking of it some more, there must be a hydraulic pressure switch under the decking, to stop the cycle upon desired compression.

Huh....


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## frenchelectrican (Mar 15, 2007)

Helmut said:


> Check this out..
> 
> In the photo, the middle button is STOP, bottom button is REVERSE.
> 
> ...


most older compacters have latching relay so once it start it will contuinde the cycle by max stroke / pressure it set up. 

I am not sure with new current verison still using latching relay or not. but I am pretty sure it is easy to convert to nonlatching mode which a operator have to hold the button during the compression stroke but on return stroke it dont need to be hold at all.

The cycle timming useally about 40 second to couple minuites depending on the set up and size and materals it have to compression it. 



Helmut said:


> Thinking of it some more, there must be a hydraulic pressure switch under the decking, to stop the cycle upon desired compression.
> 
> Huh....


It is .,, there is a hydrallic pressure reguatator in there plus pressure gauge and I know most med and larger compactors they useally limit at 1500 PSIG which it translated about 20 to 60 tons of ram pressure depending on size of ram. 

The last compactor I ran into it did have 25 HP motor on it. so sorta like souped up logspitter set up.,,


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## sbrn33 (Mar 15, 2007)

Honestly if their insurance is making this a requirement I would probably put in a small PLC like a Zelio or Logo!. 
Why not? They are asking you not you selling **** to them. Probably $2,500 for a $100 logo and about 4 hours.


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## Cow (Jan 16, 2008)

sbrn33 said:


> Honestly if their insurance is making this a requirement I would probably put in a small PLC like a Zelio or Logo!.
> Why not? They are asking you not you selling **** to them. Probably $2,500 for a $100 logo and about 4 hours.


I can't understand why anyone would install a small PLC where a simple momentary switch would most likely suffice? 

I do some PLC work, but this is NOT a job for a plc IMO. This is a job for a switch.


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## sbrn33 (Mar 15, 2007)

Cow said:


> I can't understand why anyone would install a small PLC where a simple momentary switch would most likely suffice?
> 
> I do some PLC work, but this is NOT a job for a plc IMO. This is a job for a switch.


Oh you are right. I was just upping the ante a bit, but honestly with a few safety switches it might be a decent option.


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## Jlarson (Jun 28, 2009)

Opening the loading chute door should kill the cycle. The key switch is just there to keep random idiots from running it.


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## frenchelectrican (Mar 15, 2007)

Jlarson said:


> Opening the loading chute door should kill the cycle. The key switch is just there to keep random idiots from running it.


Yep.,, it is set up like that and when the loading gate or door is open it will shut off the pump cycle quick.

I useally get call to fix those compactors once a while and useally the gate interlock switch can get off alignment and cause prevent unit start up.


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## AK_sparky (Aug 13, 2013)

Helmut said:


> Check this out..
> 
> In the photo, the middle button is STOP, bottom button is REVERSE.
> 
> ...


Change the N/C STOP switch with a N/O switch. Operator has to hold the button for full cycle, but the key is still required for the first 5 seconds.

The only pain is that you would have to hold both buttons and turn the key to do reverse, but depending on the circuit that could be easily remedied too.


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## splatz (May 23, 2015)

There are a lot of things you "could" do to make it work but in this case, I'd be very hesitant to do anything that isn't explicitly laid out in the manufacturer's documentation. 

I wouldn't want to customize this myself and assume the liability if something happens. I don't know how you're supposed to set up a trash compactor for safe operation. I think your guesses are probably right on the money but I just wouldn't want to guess.


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## gnuuser (Jan 13, 2013)

depending on the manufacturer of the machine your compactors are supposed to have safety switches *and* interlocks in the loading shoot doors, as well as the bale unloading door.
the machine should not be able to run with either door open.
the key switch is generally to prevent unauthorized use.
the biggest issue you usually have to deal with is someone bypassing the switches.
If you plan on a plc to run this install a light screen into the safety circuits 
this will shut down the machine if anyone approaches and breaks the beam.


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