[labnetwork] Suggestions for interlocking fume hoods

[Mike Young]

Sehr gut, Herr Bill! :)

We have used this approach with exactly one bench, namely the MOS-clean RCA bench. We hacked/edited the code in the bench PLC and the touchscreen HMI to recognize a spare PLC input as a bench-enable signal. The input, in turn, is driven from one of our hardware interlock boxes (8-channel IP power controller) which in turn is driven by the Coral hardware interlock code. Using this approach, the HMI will reflect the current status of the bench (enabled/disabled), and will not display the normal bench screens until/unless the bench is enabled.The ladder logic in the PLC can be arranged to disable any desired bench functions when coral disables the bench.

—Mike


> On Sep 17, 2015, at 8:23 PM, Bill Flounders <bill at eecs.berkeley.edu> wrote:
> 
> All our sinks /hoods are at least partially interlocked.
> 
> Interlock has no impact on exhaust.
> Vendor (Wafab) installed easily accessible separate relay 
> in front of 24V DIN rail so all accessories are defeated
> when tool is not 'enabled'. (e.g. QDR, rinse resistivity etc are all off).
> Some heated baths (e.g., general clean) are bypassed from DIN control and left hot.
> Other heated baths (e.g., special etch) are linked to DIN control and can not
> be heated until tool is 'enabled' by researcher.
> Any heated bath requires level sensor, over temp sensor and integrated sprinkler. 
> 
> DI deck hose was spec'd independent of the accessory panel
> and is active at all times for emergency water access.
> 
> Before posting response - I had to finally look up what the acronym 
> DIN stood for...  what a surprise - the NIST of Germany?!   Danke Schon
> https://en.wikipedia.org/wiki/DIN_rail <https://en.wikipedia.org/wiki/DIN_rail>
> https://en.wikipedia.org/wiki/Deutsches_Institut_f%C3%BCr_Normung <https://en.wikipedia.org/wiki/Deutsches_Institut_f%C3%BCr_Normung>
> 
> Bill Flounders
> UC Berkeley
> 
> 
> Weaver, John R wrote:
>> We have struggled with this as well and have opted not to interlock them.
>> The best approach we came up with was to interlock the lights in the hood. It wouldn’t really inhibit the users, but would be very noticeable if someone was working in a hood with the lights off. We didn’t really think that it would have a safety impact, but that was a concern – reading bottle labels, etc.
>>  
>> John
>>  
>> From: labnetwork-bounces at mtl.mit.edu <mailto:labnetwork-bounces at mtl.mit.edu> [mailto:labnetwork-bounces at mtl.mit.edu <mailto:labnetwork-bounces at mtl.mit.edu>] On Behalf Of Vito Logiudice
>> Sent: Wednesday, September 16, 2015 1:16 PM
>> To: labnetwork at mtl.mit.edu <mailto:labnetwork at mtl.mit.edu>
>> Subject: [labnetwork] Suggestions for interlocking fume hoods
>>  
>> Dear Colleagues,
>>  
>> Our efforts to physically interlock our tools via our lab management platform (Badger in our case) is progressing well. In most cases we are interlocking computer monitors, keyboards or computer mice with good results. 
>>  
>> My team and I have discussed how to best interlock our numerous fume hoods but were unable to settle on any one approach. For safety reasons we certainly do not want to make the hoods entirely unavailable when not enabled by Badger; ie., we want to encourage their use when lab users handle chemicals. However we do believe it would be beneficial to physically interlock them in some fashion to at least make them somewhat less appealing to use unless they are first enabled. I’ve searched past threads on this fantastic network and while I came across some great related discussions I was unable to find anything which dealt specifically with hood interlocks. 
>>  
>> I’d greatly appreciate hearing from those of you whom have interlocked your hoods or are thinking of doing so soon. I’m curious to know what service or feature you may have tapped into on a typical hood setup that might include some combination of spin-coaters, hot plates, heated/recirculating chemical baths, N2 guns, DI guns etc.
>>  
>> Thanks very much for any insights.
>>  
>> Best regards,
>> Vito
>> 
>>  
>> 
>> 
> 

-- 
Michael P. Young                                (574) 631-3268 (office)
Nanofabrication Specialist                      (574) 631-4393 (fax)
Department of Electrical Engineering            (765) 412-6728 (cell)
University of Notre Dame                         mike.young at nd.edu
B-38 Stinson-Remick Hall
Notre Dame, IN 46556-5637

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