I havent been able to find any specifications that support a difference in RU sizes between the two but recall someone stating that IT racks are 1 1/2" opposed to 1 3/4". Is this true and what wording would you look for to identify this? The reason I ask is because I really like some of the Belkin and APC racks. TIA

there are two main differences that I'm aware of...

most racks for the IT market are more than 30" deep, as most 1RU servers are about 30" in depth. the other thing that is fairly common is for IT racks to use cage nuts. this is an insert that is placed in a generic square cutout on the rack posts, rather than the posts being pre-drilled for 10-32 bolts, which is the standard in the AV world.

the other factors, which aren't always different, as Middle Atlantic has solutions for most of these issues, are such things as integration with elevated flooring systems, rack ganging, cable ladder mating, DC-DC power solutions, etc...

1 Rack Unit in IT is 1 3/4"

The rack height is the same, but there are other differences... Mostly to do with the rack screws and rail hardware.

I just had a similar conversation over at AVS...
I will post some of the conversation here.

To make it easier, his ??'s are bold, my replies are standard.

Quote:
I sell voice and data hardware and software. So I can get my hands on racks from manufacturers like; Hubbell, Chatsworth, ICC, etc...

Now I know Middle Atlantic makes the special shelves that have the nice laser cut bezel to fit around equipment that is not rack mount. But if it's standard 19", then I should be able to buy my rack, power strip, fans, etc... from say Chatsworth, and then get my "special shelves" from Middle Atlantic, right?

What is the application??
-- Free-standing in a utility area??
-- Roll out rack on casters in a closet??
-- Flush mounted into a wall??
-- Track mounted system recessed into a cabinet??

If it's free standing, then you want to use a cabinet or a full depth open rack (looking at the Chatsworth site, they call it a 4 poster).

This is going to allow you to place lacing bars on the rear rails and strain relieve your connections and stay within bend radius requirements (just like your industry). Aside from the RAMPANT use of crappy cables, intermittent terminations due to the fire hose cable twisting the termination is a major reason for HDMI callbacks. Use a decent cable, and tie it to a lacing bar to keep the weight of the cable off the termination and keep the connector straight with the socket.

They do not appear to have casters for all models, and some of the models which appear to be free standing have flanged feet forward of the front rails making it tougher to flush mount into a wall.

Also, Middle Atlantic uses 10-32 hardware.... and I don't see that as on option for CPI. They are pre-tapped for the thicker 12-24 hardware, or punched for cage nut hardware.

You could always use pre-punched cage nut rails and use 10-32 cage nuts, but they are more for server racks where you are constantly pulling hardware in and out for upgrades, maintenance, service, etc. and possibly strip out tapped rails over heavy use.

IMO, cage nuts look like hell on nicely dressed A/V racks where you may wish to use nice finishing touches such as shims and trim strips.

As for the vertical power strips, they are worth every penny IMO to get that clean look with short power cables.

Another factor to consider is weight... I am NOT a telecom expert, but I know that there are weight capacity differences between relay racks and AV equipment racks.

If you are a dealer for Chatsworth, maybe call them and get a suggestion from a sales engineer. They will have comp specs of their models to Middle Atlantic.

Quote:
I didn't catch the info about the 10-32 cage nuts versus the 12-24. Are you saying they're are not standard on both pieces then?
The default for our industry is pre-tapped 10-32 rails and 10-32 hardware...
Middle Atlantic does offer options such as cage nut and 12-24, but they are mainly for crossover users in the teledata industry!

Quote (OP):
I did call Chatsworth, but I did not get the type of assistance I wanted.
That is a red flag to me...

I know that the DIYs make decisions based on different criteria than pros, but TRUST ME that service and support is a #1 priority.... If a manufacturer can't offer you assistance to PURCHASE their product, what good will they be when you run into trouble??

In the A/V industry, Raxxess and Lowell also make racks very similar to many of the models Middle Atlantic offers, but Middle Atlantic is the class leader without question... I choose to use Middle Atlantic 100% of the time because of their excellent support.

As for Middle Atlantic, go download their Rack Tools software and lay out your system that way. The custom cut shelves are called RSH shelves, and the data base exists in Rack Tools so that you can determine the racked height and depth of each component going into a shelf...