# ESU 54677 Smoke Unit Dual



## DanCole (Feb 16, 2021)

I'm working through an installation in a LGB Mogul with an ESU 5 XL decoder sound file SO740 and a dual smoke unit. The Dual smoke seems to allow the smoke to pass by the lower fan during chuffing but runs during cylinder blowdown. Smoke unit is filled to capacity. Any thoughts? Very new to all of this. https://www.youtube.com/watch?v=0Gx9UJ1c7Ic


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## Greg Elmassian (Jan 3, 2008)

What do you think is wrong? Looks like it works perfectly, except the blowdown at the end should be with the last few cylinder movements.


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## DanCole (Feb 16, 2021)

If you look at the back bottom edge you can see where the smoke is being expelled through the lower fan. The smoke that gets past the fan is all inside the model where it gets oily. I was thinking the fan should be on very low to keep the smoke from back flowing into the model.
Thanks
Dan


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## DanCole (Feb 16, 2021)

This shows it better. Smoke Test 2 - YouTube


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## Greg Elmassian (Jan 3, 2008)

Several people have mentioned this, it's the result of the 2 smoke units not being completely independent.

No easy fix. How are you programming this unit? Is it connected through SUSI?


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## DanCole (Feb 16, 2021)

Greg Elmassian said:


> Several people have mentioned this, it's the result of the 2 smoke units not being completely independent.
> 
> No easy fix. How are you programming this unit? Is it connected through SUSI?


Programmed it with the LokSound programmer with a sound file that have the smoke sitting in it. Going to try to duck that fan outside the model.


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## Greg Elmassian (Jan 3, 2008)

Is it connected to the a decoder by susi, or is it hooked directly to the rails?


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## DanCole (Feb 16, 2021)

Greg Elmassian said:


> t connected to the a decoder


Connected to the decoder.


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## Greg Elmassian (Jan 3, 2008)

Yeah, looks like the SUSI bus connection... so programming the smoke unit needs to be done in the pass through mode, where the command goes to the main decoder and then it passes it on to the smoke unit decoder.

My thinking is that you might be able to leave the other fan idling at a low rate all the time or when needed to avoid the "backwash" in the case you do not like (understandably). The issue will be that this programming is tricky.

If you want to try you need to make friends with an expert, and they are hard to find. On GScaleCentral.com one such person exists, and he had a heckuva time.

Greg


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## DanCole (Feb 16, 2021)

Greg Elmassian said:


> Yeah, looks like the SUSI bus connection... so programming the smoke unit needs to be done in the pass through mode, where the command goes to the main decoder and then it passes it on to the smoke unit decoder.
> 
> My thinking is that you might be able to leave the other fan idling at a low rate all the time or when needed to avoid the "backwash" in the case you do not like (understandably). The issue will be that this programming is tricky.
> 
> ...


Thanks for all your input Greg. That's exactly what I was thinking if I could get that lower fan to run at a slow speed. This DCC is all new to me. I might try to just duct that fan to the outside of the model.


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## Girotek (Dec 27, 2007)

DanCole said:


> If you look at the back bottom edge you can see where the smoke is being expelled through the lower fan. The smoke that gets past the fan is all inside the model where it gets oily. I was thinking the fan should be on very low to keep the smoke from back flowing into the model.
> Thanks
> Dan





DanCole said:


> Thanks for all your input Greg. That's exactly what I was thinking if I could get that lower fan to run at a slow speed. This DCC is all new to me. I might try to just duct that fan to the outside of the model.





DanCole said:


> I'm working through an installation in a LGB Mogul with an ESU 5 XL decoder sound file SO740 and a dual smoke unit. The Dual smoke seems to allow the smoke to pass by the lower fan during chuffing but runs during cylinder blowdown. Smoke unit is filled to capacity. Any thoughts? Very new to all of this. https://www.youtube.com/watch?v=0Gx9UJ1c7Ic


Unfortunately the ESU dual smoke units are known for leaking from secondary fan, checked 2 different years production smoke units, both leaked.
Girotek


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