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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => LAB Lounge => Topic started by: Jeff Bankston on August 10, 2018, 05:02:19 AM
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I recently bought a nice used Midas H2000 48 channel. It has 3 power supplies and all the daisy chain cables. My question is do I turn on all 3 power supplies at the same time and leave them on or turn on just one and if it quits working turn on another ?
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Turn on all 3.
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If you turn on all 3 and have a major power failure on the legs feeding the power supply, all 3 die.
I would leave at least one unplugged but ready to connect in case of major failure.
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I recently bought a nice used Midas H2000 48 channel. It has 3 power supplies and all the daisy chain cables. My question is do I turn on all 3 power supplies at the same time and leave them on or turn on just one and if it quits working turn on another ?
Take all power supplies to a good repair shop and have them serviced.
Ive been told a single power supply running is not enough for the desk. This of course depends on the size. The one I am thinking of might be more channels, its been a while.
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If you turn on all 3 and have a major power failure on the legs feeding the power supply, all 3 die.
I would leave at least one unplugged but ready to connect in case of major failure.
+1 - no point in exposing *all* your PSU's to a power event.
BTW, there used to be conventional wisdom that when one supply died it would kill the other. The usual reality was that people would routinely use both, all the time, and never test them individually - so one might have died months before but it wasn't noticed until both were dead.
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If you turn on all 3 and have a major power failure on the legs feeding the power supply, all 3 die.
I would leave at least one unplugged but ready to connect in case of major failure.
If you have that catastrophic of a failure then I doubt the FOH console being dead will be the worst of your problems...
Still a good idea though...
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If you have that catastrophic of a failure then I doubt the FOH console being dead will be the worst of your problems...
Still a good idea though...
Not always.
Modern amp PSUs are far more robust IMHO than these PSUs, so a major failure that would send the console PSUs on the up in smoke tour would often just cause the amps to go into protect.
If you had something like a X4/X8 the amps would defiently survive long past console PSUs.
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If you are looking for additional information or service, your best bet is to drop a line to Jim Sawyer at Sawyer Audio (http://sawyeraudio.com). He's probably one of, if not THE authority on these desks in the US.
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ALWAYS have one PSU disconnected from the other PSUs and incoming line voltage. Why? Because what took the first PSU down didn't auto-magically fix itself. When you hook the the second PSU and it fails, you at least have a working PSU for when you discover the shorted umbilical power cable or the massive short inside the console.
While it's possible that a PSU will spontaneously fail for no *external* reason (Soundcraft, 30 years ago), it's unlikely. Your 20 year old Midas PSUs should be recapped, and possibly the bridge rectifier replaced as well.
Been there, done that, gave away the t shirt.
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I recently bought a nice used Midas H2000 48 channel. It has 3 power supplies and all the daisy chain cables. My question is do I turn on all 3 power supplies at the same time and leave them on or turn on just one and if it quits working turn on another ?
On a 48ch frame two should run the console without issue. The large frame H3K's needed all three on.
Keep the 3rd unplugged from the mains and console so it is truly a spare...aside form shorts in the console or psu cables that protects you from lost neutral connections in the FOH power run. Lived that dream.
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[...]psu cables that protects you from lost neutral connections in the FOH power run. Lived that dream.
Always unplug the white Camlock first to test if the power is still on? (For those who don't work with Camlocks much, this is a joke; please don't ever do this.)
In (only slightly) more seriousness, in theory you could probably run most modern consoles off of hot-hot-ground 208V, so I suppose a NEMA 6-15 (etc.) to IEC 60320-C13 would, in fact, be a PSU cable that protects you from lost neutral connections in the FOH power run...
-Russ