Rackmount Ranger: Is the BR1 brush grommet panel ROHS compliant? What kind of finish does it have? Is it certified to the UL.94.V-0 flamability rating?

The BR1 and its cousin the BR2 are 1U and 2U rackmount brush grommet panels respectively. They are ROHS (Restriction of the use of Hazardous Substances) compliant, which makes them able to be imported into Europe for use in IT and networking applications.

The panels are painted with a black epoxy powder coat, and are made of fire resistant materials in compliance with UL.94.V-2.

How can I tell if my Surge Suppression Still Functional? How do I tell if I have exceeded the limit.

Most power strips on the market today use the Metal Oxide Varistor (MOV) as the primary component for suppressing surges and spikes in electric voltage. The MOV is an electronic component that resembles a capacitor. It is typically a round disk with two electrical leads, and comes in various sizes for differing levels of protection. See the photo below of typical MOVs.

Most MOVs are made from zinc oxide with differing amounts of manganese, cobalt, bismuth, and other metal oxides. This matrix of materials is then placed between two metal plates to which the electrical leads are attached. The boundary between grains forms a diode junction, which allows current to flow in only one direction. The mass of randomly oriented grains is electrically equivalent to a network of back-to-back diode pairs, each pair in parallel with many other pairs. The diode pairs react differently at high and low voltages. When low or normal voltages are present, there is very little current flow through the MOV. However, in the presence of high voltages, the diode junctions break down, and a large current flows through the MOV. Another way to say this is that the MOV has a very high resistance at low voltages, and a low resistance at high voltages.

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The two most important parameters to understand when trying to choose a power strip are:

• What are you plugging it into?
• What are you pluggin into it?

The “source� you are plugging the power strip into determines what voltage and amperage you need the power strip to be compatible with. There are many options, but most are combinations of these amperages and voltages:

• 15Amp
• 20Amp
• 30Amp

• 110-125Volts
• 208 Volts
• 220-250Volts

Knowing the source will determine the amperage and voltage you need to match.

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I have an application where I am putting 28 small devices into a rack. Can I power them all from one circuit? I want to use a 20 receptacle power strip and a 10 receptacle power strip plugged into the same wall outlet.

Generally speaking, people can fall into a trap by assuming that just because they have a large number of receptacles, that means they can fill up a power strip and not worry. Unfortunately, such is not the case.

A single 15Amp circuit, like the one in your wall at the office or at home, can provide 12 amps of continuous, steady state power. Having two receptacles in the wall does not double the amount of power available, since the wall receptacles are powered from one wire, and represent a single circuit. To tell how many units can be powered by a single circuit, you need to add the amperage that each unit pulls. Once you get to 12, you stop adding units to the power strip. If you go over 12, disconnect the smallest (by power used) component, to get to 12 exactly, or just below. Power strips with current monitors are excellent for helping you determine how much current a group of components is pulling. Any extra receptacles should remain unused. They can be closed off with plastic outlet plugs.

The problem with plugging in too many units is that each unit will be underpowered. It may still appear to operate fine, but it may not be getting the correct power needed to operate properly. If it is a computer or server, less than proper power can cause data loss and other problems.

Putting 28 small devices in a rack is OK, as long as each device averages .428 amps (12 divided by 28) or less. Since there are a lot of devices out there that only require about .4 amps, this should be OK.

Note that if you have a 20Amp circuit, then the continuous amperage available is 16 amps.

Thanks for your question!
Rackmount Ranger

Are LAN Racks Dead?

Before answering the question, let’s define some terms. A LAN rack is a series of surfaces with certain structural supports. The supports can be of varying styles like cantilever or four post, and the rack itself can be mobile or fixed in place. LAN racks can do double duty as work stations or tech benches while providing additional surfaces for the placement of servers and peripherals. In a LAN rack, most items are shelf mounted.

LAN racks are different from computer cabinets. Cabinets are usually fixed in position, and provide a frame which supports moveable rack rails. In a cabinet, most items are rack mounted.

Each type of structure has advantages and disadvantages.

Note that the two “hottest� issues for data center managers today are thermal management and remote management. The trend in data centers is to go with higher density, more power, and fewer people (and their work stations which take up space). The amount of heat being generated in a data center is extreme, and keeping all the servers cool is a major challenge. Cabinets are ideally suited to this environment as cold air can be supplied at the front of the cabinets (where most servers pull in the cooling air) while warm air is kept away from this area. Regrettably, LAN racks have no provision for ensuring cold air is available to provide optimal cooling of servers. In addition, LAN racks, while capable of hosting remote power and environmental monitoring, go against the trend of having fewer people at work in the data center. Data center managers want to remotely control and reboot servers, while remotely monitoring critical environmental factors such as temperature and humidity. This capability is not a LAN Rack strength.

So for data center applications, my assessment would be that LAN Racks are dead. However, for smaller applications where a more efficient use of space is important, and where thermal management is not such a challenge, today’s LAN Racks can fit in perfectly.

My servers run very hot and are in an unmanned location. I have provided air-conditioning but I am still worried about potential failure due to heat. Also, it is located in a very humid area. I would like some way of being notified when the temperature or humidity exceeds a certain level. The solutions I have looked are very expensive. Do you know of a low cost method of achieving this?

The SH-2+ sensor hub with temperature and humidity sensors could work very well for you. When the unit is installed, you assign an IP address to it that is on your network. You can then set the thresholds you want so that when a particular mark is exceeded, then the unit emails you an alert. There are two upper and two lower thresholds that can be set for both the temperature and humidity parameters. The sensor hub has a modem port so that it can also call you as well as email you. There are many other features included in the sensor hub, including the ability to track the history of any parameter. This is an easy and inexpensive way to assure yourself your high dollar components are not overheating or exceeding other environmental parameters. If you want to be able to do something about an abnormal temperature or humidity situation, the sensor hub works well with the RPM 1601 family of remote power managers.

My network room is located in a very old building with small elevators and staircases. My problem is adding new server cabinets. I need a cabinet that is very sturdy but ships unassembled. Do you have any ideas?

There are a variety of solutions for situations like this. There are knock-down server cabinets and knock-down frames that can solve the problem of getting heavy components up into remote offices. Depending on your specific needs, one of these solutions should work for you. Two examples are the knock-down server cabinet that ships flat on a pallet, and the knock-down “anywhere rack� that ships in a series of boxes via UPS.

I am planning to put my home entertainment system on a rackmount frame. I have never used rackmount and do not understand the dimension listed. Particularly, is a 19� rackmount 19� wide? If not, what is the usable width?

The short answer to this question is nominally 17.5� of usable width. If you would like to know how this came about and have no fear of the unknown, then read on!

There are three standard rack widths related to Datacom and telecom. These are 19, 23 and 24 inches respectively. 19 inch is standard for Datacom. 23 inch is standard for telecom, and 24 inch is a combination broadcasting/telecom standard that is not that much in use today.

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If I were to invest in a temperature sensor for my rackmount server enclosure, at what temperature would you recommend that I should set the internal temperature threshold for?

There are a number of things you can do with the temperature sensor to make your life easier. The first is to recognize that there are two thresholds for high and low temperature that can be set by the administrator. Secondly, there is an adjustment feature with the sensor hub that allows you to put in a correction factor that will match the sensor hub reading to the room thermostat (if you desire).

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The short answer is no. The long answer is not so simple as it really depends on the building codes in your municipality. In general there are three issues related to bolting down a computer cabinet:

· Structure of the sub-floor and/or raised floor

· Anchor bolts

· Anchor brackets

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