Power consumption, over-heating, & thermal shutdown

[Neil Hetrick]

Hello there,

I discovered this forum while searching for help with studio design/set-up (particularly with rack equipment), and was hoping I could ask a few questions about set-up of outboard/fx racks, their ventilation & overheating, and studio electrical consumption.

I have a couple large rack cases filled with outboard gear in my home studio (see attached photo for an example of one of these), and have recently had a problem with one unit (a Roland SDE-330 digital delay) shutting off or "dying" for no obvious reason other than that it gets VERY hot. I have since learned that this might be a phenomenon called "thermal shutdown", and that this problem may be related in some way to an excessive electrical load on the studio-room electrical circuit (i.e., too many amperes of current draw causing a reduced voltage in the studio, thereby making equipment run hotter and hotter).

In my studio, all electrical devices (save for my computer’s LCD monitor and the room lighting) are connected to a Furman IT-1220 balanced power transformer which is running off a standard (for the USA, anyway) 15-amp room circuit. The LED voltmeter on the IT-1220 indicates that voltage sags as I power up more gear, and it hovers around 114-15 Volts with everything powered up and music playing loudly through powered monitors.

After several hours with everything on, the effects and outboard racks get HOT (I’ve measured chassis temperatures of some units in excess of 46˚C), and the whole room really heats up quite a bit (there can be a 6-8˚F temp. increase, especially if I don't crank the AC in response). Setting up a Furman AR-1215 voltage regulator upstream of everything else doesn't affect the voltage drop (Furman's literature on that device does say that it will regulate power to 120 Volts +/- 5 Volts). I’ve also set up a Furman PM-PRO power conditioner, which has an LED ammeter, upstream of the IT-1220 to verify that my studio isn’t drawing too much power, and I’ve discovered that, at maximum usage, my studio is drawing maybe 9 amperes total current, which doesn't seem dangerous to me in a 15 amp room, but then I'm no electrician.

What I've seen with respect to the Roland delay is that, once it gets hot in the above setup, it shuts down, and once allowed to cool off a bit, it will power up only briefly and then shut down again. This is the case regardless of whether it's in the densely-packed effects rack or not, but it definitely gets hotter in that rack than out of it, so the shutdown occurs sooner when it's in the rack. Interestingly, when I plug it into a wall socket in another room (which isn't providing balanced technical power) the Roland delay will stay on much longer, but even there it will eventually shut down. This leads me to believe two things: 1) that it has become damaged, and 2) that it doesn't seem to like balanced AC power in the condition it's in now. At this point I just need to find out if the situation in my studio has led to the damage or not, since I don't want other gear to follow down that path.

Here are a few questions, then:

1) Is it safe to run many rack processors in close proximity to one-another at 114-115 Volts AC for extended periods (10+ hours), particularly if the chassis temperature of this gear can reach or exceed 46˚C?

2) If my Roland SDE-330 was damaged in some way by my running it under the conditions described in the above question, is it possible that some of my other rack processors could already have been damaged to some degree, just not enough so to cause them to shut down / fail? In other words, I'm wondering if heat-related or electrical stress-related damage builds up in a cumulative way over time, or if it's an "all-or-nothing" kind o thing.

3) Can anyone viewing this forum recommend a studio designer with electrical experience (or an electrician with pro-audio experience) in the Washington, D.C. (USA) area that I can hire as a consultant for an hour or two to come by and check out my studio space and help me figure things out?

Thanks in advance for any help here... I mostly want to determine whether or not the way I'm running my studio setup as a whole may lead to other gear prematurely failing due to a "thermal shutdown".

[Niccie]

Well, i'm not an expert but

1- no it's bad, that temp ir risky for the health of your fx machines.
You may want to cool the racks up with some kind of vent system or/and spacing the FX using for space the same one that is consumed by the actual unit. that would make you use more racks but i'tll save a lot of money in repairing or replacing your fx units. U can also try shutting them off when u dont use them, or just the one u're not using at the moment.

2- Yes definitively.

3- Sorry i don't i'm from Argentina.

Hope i've been usefull.

Regards

[Aaronw]

1) Is it safe to run many rack processors in close proximity to one-another at 114-115 Volts AC for extended periods (10+ hours), particularly if the chassis temperature of this gear can reach or exceed 46?C?

Believe it or not, alot of "effects" units usually require some venting. Check each piece of your equipment. If any of them have vents on the top or bottom sides of the chassis, definately give them some air.

2) If my Roland SDE-330 was damaged in some way by my running it under the conditions described in the above question, is it possible that some of my other rack processors could already have been damaged to some degree, just not enough so to cause them to shut down / fail? In other words, I'm wondering if heat-related or electrical stress-related damage builds up in a cumulative way over time, or if it's an "all-or-nothing" kind o thing.

Most qear really doesn't pull much juice. It's possible the equipment suffered from a thermal issue. It's not uncommon. Where I work, the first thing we do w/ a new amplifer we get from a new vendor, is put it through the paces. Give it a dead short and throw a blanket over it. The end result is usually similar to what your experiencing. You may need to have a relay replaced or other component. (I'm not too familiar w/ thermal protection systems, except they can be good to keep something from catching on fire).

You might pop the top and see if it got so hot that the solder melted and joined w/ another part of the circuit. I've seen this happen as well. Or if you see any burned components.


As far as Q3, don't know anyone in DC.

Hope this helps some. Steve is more the electrical guru here when it comes to the more in depth electrical loads, etc. But I would definately give the gear a little more breathing space. It'll last longer.

[Neil Hetrick]

Hello again,

Thanks to those who have posted replies so far... your insights & suggestions are much appreciated.

In doing a bit more research online, I discovered a document (a “white paper”) on thermal management by Middle Atlantic Products president Bob Schluter called “Controlling the Temperature Inside Equipment Racks”. The document is downloadable (as a .pdf file) from the tech support area of their website:

http://www.middleatlantic.com/techs.htm

I found it particularly interesting to read that, for optimal airflow via natural convection, the top and bottom of a rack should be well vented but not the middle, since eddies there can interrupt airflow and “short circuit” what’s called the “chimney effect” of heated air rising via thermal gradients to exit at the top. I also found it informative that devices containing digital microprocessors (i.e., effects processors and the like) are especially susceptible to heat damage (which apparently can occur above 85˚F), while purely analog devices (like VCA compressors) are perfectly fine in a high-temperature environment.

I am somewhat irritated that manufacturers of digital effects processors design units to supposedly fit in a single rackspace but which in fact cannot really be placed in a single rackspace without suffering potential harm from inadequate ventilation. This is particularly the case with devices having ventilation slots on their top or bottom panels, thereby requiring empty space above and/or below them and completely negating their single rackspace design. Such “single rackspace” devices could never be appropriately positioned in a single rackspace, even if the adjacent spaces were filled with completely passive, cold-temperature units like the rack-mount Ebtech hum eliminators (HE-8), which consist only of I/O jacks and internal transformers. That’s just silly, and in my opinion, poor design, plain and simple.

Anyhow, thanks again to all for your help... this site is certainly a great resource. Cheers,