Connecting studio equipment to AC power

[ChiefOperator]

Hello everyone,

I just got involved in a small market station that needs a studio upgrade. Of course, we will need to supply AC power to the on-air equipment, which is housed in racks and studio furniture turrets. Currently, everything is plugged into power strips, which in turn plug directly into wall outlets.

I'm curious how your studios are set-up. Are you using power conditioners or surge supression or do you plug directly in? Could you please tell me the best arrangement to connect to AC power. I want a professional installation.

Thanks!

 

[thebeaver32]

It's best if each studio and rack have its own source of power, that is, its own circuit breaker in the electrical panel. If you want to install surge protection, the best approach is one heavy-duty unit installed at the main panel. As far as outlet strips are concerned, they are a way of life for radio. It's almost impossible to supply enough wall outlets to plug everything in. But it really isn't a problem. In a radio studio, or rack for that matter, the problem is you have lots of things to plug in, but they each draw very little power. A hundred watts at most, and some down to 20 or 30 watts. Just not much of a load. The exception is computers. They draw several hundred watts, and the CRT type monitors also draw considerable power. You will want to put the computers and monitors on a UPS, and try to plug the UPS directly into a wall outlet, not an outlet strip. This is especially critical if the computers are your automation system. Oh, yes, if you have enough outlets, try to avoid daisy-chaining the outlet strips. Sometimes you have to, but remember if the circuit breaker or switch on the first outlet strip trips, the whole string of strips goes down.

Hope all this helps.

 

[NE Miss Radio]

I STRONGLY agree about using the UPS's. I had everything in my studio airchain on a UPS. It took me four of them (automated CD's in another room, Computer, board, and processing/STL rack). They run from 40 to 150 bucks based on output. Well worth it IMO. I was able to keep the studio on air for about 30 minutes, long enough to survive most in-town outages where the XMTR had power. And that was with a 350VA, two 650VA's, and one 1100VA.

But wait, there's more--they also have some surge protection in most of them.

In my studio, I had one set of outlets on one breaker in the front and back of the room on the north side and a mirrored set on the south side. Just in case.

 

[RadioFlyerAtl]

I have used Middle Atlantic power strips in all of my new rack installations with great success. I order these with the surge protection and EMI filter option. The surge protection is by MOV and offers all three modes: L-N, L-G, N-G. The EMI/RF suppression is greater than 20 dB between 0.1 and 1 MHz. They offer many different sizes and options, and these easily mount into any Middle Atlantic rack or other make of equipment rack.

Some of the best surge protection products out there are made by PolyPhaser. We have a few of their IL series in-line surge protection units on the AC mains for a few transmitter sites, and have never had to worry about power line surges. They are a little pricey at around $1,500, but it's a great insurance policy, in my opinion. They also offer great surge protection products for coaxial line applications.

 

[sparks794]

If you can't afford UPS for everything at least put it on the items needed to stay on the air. One of my stations did this with the console, automation, and STL's and it makes a worls of difference. They stay on uninturrupted until the generator is up and switched over without inturruptions.

The idea of each rack on its own "feed" is a great idea. A TV station that I was at did this and not only did it help isolate during a power hit but it also made staying in business a hell of alot easier when there was a problem. We had better isolation and less downtime this way.

 

[NE Miss Radio]

I forgot to add earlier, no one I know ever said "I wish I'd spent less time, effort and copper making sure all my grounding was done properly."

 

[boiseengineer]

When the electrical inspector shows up (or even the fire dept in our case) remember that those power strips with the cord on them are considered a "temporary power tap". All sorts of no-no's when using those.
Highlights are (NEC):
Cords can't be run through or under behind anything (holes in walls, furniture, carpet, etc...).
Can't be mounted in any way (screwed or sticky-taped to the furniture).
Can't daisy-chain them.

Good luck!

 

[ChiefOperator]

Everyone--

I appreciate all the posts and have gained some great knowledge

Thanks!

 

[nyc_eng]

If you can't afford UPS for everything at least put it on the items needed to stay on the air. One of my stations did this with the console, automation, and STL's and it makes a worls of difference. They stay on uninterrupted until the generator is up and switched over without interruptions.

The idea of each rack on its own "feed" is a great idea. A TV station that I was at did this and not only did it help isolate during a power hit but it also made staying in business a hell of alot easier when there was a problem. We had better isolation and less downtime this way.

the danger there is in the event of a major power disturbance, like a lightning strike for example, the surge could enter through equipment not on the UPS and just directly on utility power, and then travel through audio or data cabling to gear that you thought that you had 'isolated' from the power grid. If you must go the cheap route, make sure you have true surge protectors on anything that connects back to protected gear via copper. Even that isnt ideal since that equipment isn't really isolated from the power grid, but it certainly offers some additional protection. It might seem costly to do things like this the right way, but compare that to the cost of being off and not being able to run spots and you usually can justify projects like a master UPS if presented to mgmt correctly.

...and obviously it goes without saying make sure that your grounds are all in check.

 

[Robert Bass]

When the electrical inspector shows up (or even the fire dept in our case) remember that those power strips with the cord on them are considered a "temporary power tap". All sorts of no-no's when using those.
Highlights are (NEC):
Cords can't be run through or under behind anything (holes in walls, furniture, carpet, etc...).
Can't be mounted in any way (screwed or sticky-taped to the furniture).
Can't daisy-chain them.

Good luck!

Never heard of any of this... Where I work, the techs installed UPS units and attached 6 way power strips plugged into them. It's a necessfity, since some of the equipment is racked quite far from the UPS units, and there's little room for additional UPS's. All of this is mounted in an enclosed, U shaped studio furniture setup. You can only access the electric wiring by removing the backs of the furniture units. Been this way since 1997 w/o any problems.

R

 

[boiseengineer]

Not a problem until an anal inspector has you open panels. Writes you up for violations if you don't emmediatly "correct" the problem.

 

[Robert Bass]

Not a problem until an anal inspector has you open panels. Writes you up for violations if you don't emmediatly "correct" the problem.

Primary AC is routed directly to the AC outlets in the furniture, from a conduit. This was installed by an electrician. Standard 3 prongs, grounded outlets are connected to that wiring.

The UPS units use three prong plugs for power supply, and all outgoing outlets are also three prong. There was only enough room inside the furniture for two UPS units. 6-way power strips were required to extend critical equipment to the UPS units.

Although I am aware some UPS manufacturers have stated it is unwise to use 6 way strips between the UPS and the equipment plugged into it, since it voids the warranty. I am unable to find NEC regulation forbidding the practice.

No electrical inspector has even suggested this setup violates any regulation.

R

 

[boiseengineer]

It all goes back to if the inspector considers the cord and the power strip to be in a restricted ventilation area. The ampacity rating of the device / heat buildup allowed is for an open & unobstructed placement of the conductors. Also, protection from damage to the conductor if it's run through a little hole between sections of the furniture. It made a difference in our case if the furniture or rack was considered to be permanent or "portable".

 

[OnTheAir123]

We use APC rack mount 1500W UPS units in the studios to hold up everything with great success. They are also used in the "Rack Room" to hold up the STL transmitters, STL Digital Encoders, Servers, and related equipment.

Normally the UPS units only have to hold for about 30 seconds until the generator cranks and transfers the load. If the generator were to fail, we only have a "Stay On The Air Capacity" of about 20 minutes. The 45kw generator supplies power to the entire studio wing of the building so it pulls everything from the studio equipment to the air conditioning for 5 stations and 3 production rooms.

If you have a UPS that can't pull everything, don't plug anything directly into the wall. Most UPS units have outlets that are UPS supplied and outlets that are surge protected only. Have one power strip that is plugged into the UPS outlet and mark it UPS. Plug "Stay On The Air" items into this strip. Have another power strip plugged into the "Surge Only" outlet on the UPS and that is for items that require surge protection only and are not critical for staying on the air.

For surge protection, the whole building protector approach is always best but sometimes you have to do with what you have to work with. We use the LEA International surge protectors at our transmitter sites and they work VERY well.

Ground, ground, ground......