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Conference netcad::hub_mgnt

Title:DEChub/HUBwatch/PROBEwatch CONFERENCE
Notice:Firmware -2, Doc -3, Power -4, HW kits -5, firm load -6&7
Moderator:NETCAD::COLELLADT
Created:Wed Nov 13 1991
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:4455
Total number of notes:16761

3297.0. "DEChub 900MS on its back ?" by BBPBV1::CARTER (Ivor Wood saved me from insanity) Tue Feb 20 1996 06:41

    Hi,
    
    An OEM is building a DEChub 900 backplane into a 'operators' desk for
    in a power station. The hub will be loaded with both 900 and 90
    modules.
    
    The desk is large but has restrictions with vertical space. The OEM has
    suggested either mounting the backplane horizontally in the desk to get
    round these restrictions.
    
    Has anyone done this before ? What is likely to break/melt if they do
    this ?
    
    Thanks
    Glynn
T.RTitleUserPersonal
Name		DateLines
3297.1NETCAD::THAYERTue Feb 20 1996 09:0921
	No problem mechanically. Lot's of folks in the lab have 
	horizontally mounted hubs. CSS even built a special unit 
	for the military with horizontally mounted hubs.

	Restrictions on vertical space may imply limited airflow
	for cooling. Make sure there is an established ventilation
	path with enough airflow to keep the local ambient below
	40C (50C if using the new H7894 power supplies). And make 
	sure the module & PS inlets and outlets have
	at least 10cm (4") clearance. Extra care with cable dressing
	may be necessary with a horizontally mounted hub to avoid
	restricting airflow.

	I've never measured temperatures in a horizontally mounted
	hub. Modules with fans wouldn't care. 90 modules, cooled by
	natural convection might, but worst case has always been
	standalone lying on a flat surface. I'll run a few numbers
	and let you know if it might be a problem.

					John
3297.2take care ...NETCAD::CURRIERTue Feb 20 1996 11:498
    I have several hubs on benches in my lab.  One thing that you must be 
    VERY careful of is insertion & removal of modules.  Is is easy to bend
    pins on modules & power supplies when inserting them in a horizontal
    hub.  That's the only problem we've seen.  
    
    -sheila
3297.3NETCAD::THAYERFri Feb 23 1996 17:289
	RE .1

	A little thermal analysis shows that indeed, laying a hub flat
	on it's back make an insignificant difference in operating
	temperatures for 90 and 900 modules.


					John