New studio space, need clean power for gear

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getreel
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New studio space, need clean power for gear

Post by getreel » Fri Sep 29, 2006 7:42 am

I am moving the studio into my new location during the next two weeks. My old location had all brand new wiring and isolated ground, etc. It was meant to be a studio evne though it was old and ugly it had been re-wired. The new space has standard electrical wiring that's a patchwork of grounded, non-grounded outlets, and possibly neutral tied to ground in the breaker box. Which leads me to my question. I have an unused circiut I can wire up to a new 4 way recepticle and use for the big gear like my MCI, and Soundtracs console. It's a 20 amp circuit that used to be for a window A/C unit. It's ground is probably not isolated although it is a grounded recepticle. Two other outlets in the studio space are not grounded. I'm thinking of connecting the extra unused circuit and then using an isolation transformer or a good power conditioner. I have in one of my racks, a Furman PL-plus unit, but I also have a regulated power supply/UPS that puts out 6 amps and has surge protection, overload alarm, etc. Can I get away with using something like that or do I need to drive a new grounding rod outside and isolate the studio from the rest of the building. The building has a lot of fluorescent lighting as well. So how much current does an MCI JH16 draw? Should I buy a few more power condtioners and run it seperate from the racks and console or should they all branch from the same? Will one unit that supports 6amp load hold all my gear?

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Post by covert » Sat Sep 30, 2006 3:27 am

I believe that, in most places, the neutral tied to ground is REQUIRED by code, unless you have a balanced power transformer rig. Any and all ground stakes beyond are also required to be tied to the main ground and neutral.
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brianroth
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Post by brianroth » Sat Sep 30, 2006 3:30 pm

Indeed, the National Electric Code requires that the neutral and ground conductors be bonded (ie, connected together) at one and only one spot at the service entrance. It is dangerous to do anything else.

As for the current draw on the MCI, look at the AC mains fusing on the rear of the machine is there isn;t a "spec plate" on the deck somewhere. I seem to recall a 5 Amp fuse there but could have a faulty memory.

My rule of thumb is to use the size of the mains fuse on a piece of gear if there is not a plate or sticker with that spec on the unit.

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getreel
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Post by getreel » Sat Sep 30, 2006 4:51 pm

It has two 5 Amp fuses. one for tape and one for audio. There is no plate anywhere that I have found, but mine is missing the back cover or covers(?) Should I go with a condtioner with Voltage regulation or an isolation transformer? Does it make any difference if I use my existing outlets without ground connected? or should I wire in my extra circuit that appears to have ground even though it is tied to neutral in the panel like everything else?

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brianroth
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Post by brianroth » Sun Oct 01, 2006 1:40 am

I suspect there is no single perfect answer, but there are a ton of possible AC mains "gizmos" available!

You mentioned owning "...a regulated power supply/UPS that puts out 6 amps...". By that description, it *sounds* as if it's a true uninterruptable supply that continually creates an AC output via its internal inverter circuitry. That is a premium unit, since the more commonplace "backup" units feed AC mains (with perhaps some filtering and/or surge supression) to the load under normal conditions, but use a relay or some-such to switch to inverter power from the internal battery when the power fails. The cheaper "backup" unit does essentially nothing to regulate the incoming AC mains voltage, but at least it should keep your computer/whatever running long enough during an unexpected blackout to safely shut down the computer.

Other types of AC voltage regulators include a ferroresonant transformer (often called a "Sola", from the name of the inventor, and the name of a company that sells that type of unit). Ferros are big, noisy (the xfmr cores tend to buzz) and run hot. Without knowing what the specs of your "UPS" are, I can only speculate.

On a lower scale, an isolation transformer does nothing to regulate the incoming AC mains voltage, but a decent one with an electrostatic shield between the primary and secondary might help filter out hash/glitches from the incoming mains.

How glitchy IS your incoming power? Are you in an area with a bunch of manufacturing plants down the street, or more commercial/residential?

As for the MCI JH-16....I dug out the manual for the later JH-24 machine, and it indeed has a pair of 5A fuses tied from the AC mains..one for audio, one for the transport. That implies a current draw of up to 10 amps under worst-case conditions. Otherwise, I could find no info in the "specs" section of the manual (although the machines' weights are listed...up to 624 pounds for a 24 track <g>). SIDEBAR: Ampex did list the power consumption in the MM-1200 manual I have, and a 24 track is listed at 1.2 kVA...which would be 10 Amps, give or take.

Soooooooo...based upon what I can glean, I'd power the MCI and the desk from the 3-wire 20A circuit. I'd install a second 3-wire 20A circuit *from the same phase leg* for everything else. Put the UPS on the second 20A circuit and use it for any "computer gizmos", since they hate being slammed off.

Just about any "reasonably sized" studio (IE, not talking about a huge SSL or Amek desk with multiple tape machines and a huge stash of outboards) can be powered from only one or two 20A circuits. Be sure the circuits have totally independent wiring back to the breaker panel, and all circuits are on the same phase leg.

Bri
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getreel
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Post by getreel » Sun Oct 01, 2006 12:23 pm

The incoming power here seems solid and not too bad. I'm in a residential area now. It shows about 117V on the Furman's voltage meter. The UPS I have does have the AVR(automatic votage regulation). I have connected the computer to that. The tape machine for now will run off the Furman PL plus. It handles 15 Amps. I have run everything in my studio from the Furman before with no trouble actually but it may not have been a good idea. Thanks for your help. I know what I have to do now. I have the electrician coming to look tomorrow at wiring up the second 20 Amp circuit. Then, I just need to fix the autolocator on my ALIII remote that doesn't seem to work after being moved :(

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Post by brianroth » Sun Oct 01, 2006 11:57 pm

Good deal...a pair of 20A circuits should easily handle what you have with room for future expansion. You might have the electrician use his "Amprobe" to measure the actual draw of the recorder, desk, etc. to get real-world numbers.

As for the AL III going flaky, suspect connectors.

Bri
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getreel
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Post by getreel » Mon Oct 02, 2006 8:08 am

I thought the problem with the ALIII was the cable because there was a splice in there that could have been damaged when moved. I respliced it however and the problem is exactly the same. Tape Counter works and all transport functions seem to work. The Locate position comes on to something other than OO.OO It comes up looking like this:
3.<blankdigit>2.2 I can push the keypad and it will change but not correctly and not every key causes a change. Reset works sometimes and seems to reset to 3.<blankdigit>2.2 I was afraid to try locate key for fear of it totally freaking out.
What connections should I check? I have already cleaned the 3 plugs and sockets for the remote. Do I need to open the remote and look for unseated ribbon cables or something?
I may be calling you for help on this later.
BTW, it it OK to run the machie like it is without hurting anything? I can write the tape time numbers down and locate by hand. I have a session coming this weekend and need to use it.

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brianroth
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Post by brianroth » Mon Oct 02, 2006 10:55 pm

I'm spinning this off as a new topic....

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