| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 552.1 | | QUIVER::SLAWRENCE | | Thu Dec 09 1993 13:16 | 10 |
| I'm not sure this answers your question, but the maximum power for the
hub is 560 watts (140 watts X 4 power supplies), and it would actually
draw no more than 3/4 of that because the 4th supply is redundant (3
will power a full hub).
If that still results in the higher number, don't dispair; if all you
are talking about is repeaters they draw even less than that.
You can calculate the total power for the hub from the table Ed Buzzel
posted the other day.
|
| 552.2 | Thanks | VAXRIO::ROLF | Vaporware Design Specialist | Thu Dec 09 1993 13:43 | 14 |
| Thanks -.1
You probably helped me reach a conclusion, indirectly:
If we have 3 supplies actively delivering 140 Watts each, they total
420 Watts, so even if the power supplies run at a low efficiency rate of
50%, that would still only total 840W from the AC mains, so a 1 KVa UPS
should surely be able to handle that load.
Can anyone else confirm?
Thank you!
Rolf
|
| 552.3 | still not happy | VAXRIO::ROLF | Vaporware Design Specialist | Mon Dec 13 1993 12:01 | 14 |
| Here I am, coming back to my own initial question.
Now I need to know if the HUB900 power supply is of the switching type.
I know most supplies today are, but I cannot see it in black and white
anywhere, and I need to take a decision between configuring SHORT-break
or NO-break units.
I am thinking of using one 1.5 KVa Short-break unit for each pair of
HUB900's.
Am I going to be committing a crime?
Rolf, DEC Brazil
|
| 552.4 | the authoritative word | QUIVER::SLAWRENCE | | Tue Dec 14 1993 16:04 | 12 |
| I forwarded your question to the power guy and got the following back:
The answer is that the power supplies for the HUB 900 are switching
power supplies. Operating frequency for the AC-48V converter front end
in each supply is approximately 90kHz. A fully loaded system (3
supplies at close to max load) will draw somewhere near 1kVA. If the
two HUB's mentioned in the attached message are not near full load,
then they'll probably be fine operating from a 1.5kVA short break
system. If the load increases, then I'd suggest a 2kVA system. At first
glance this appears to be overkill, but when you consider that the
supplies are not very efficient due to the two conversion stages
(AC-48V and then 48V to 5 and 15V) then it makes more sense.
|
| 552.5 | Note of Thanks | VAXRIO::ROLF | Vaporware Design Specialist | Wed Dec 15 1993 07:40 | 5 |
| -.1
Thank you for helping to get this answered.
Rolf
|