Mary Blair Elementary School

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In early March, 1996, inspired by California's well-organized NetDay, the idea of a Mary Blair NetDay was hatched. Originally, we planned to wire five classrooms with two Category 5 lines each, plus the Media Center with two lines.

With generous support from the PTO, the Student Council, and the Principal, we eventually received enough funding to cable every one of the 23 (twenty-three) full-sized classrooms, except Art and Music. Each classroom was to receive two Category 5 lines and the Media Center was to receive four Category 5 lines.

[Click here to view the floor plan of Mary Blair Elementary School.]

On Saturday, March 30, 1996, about a dozen volunteers worked at the school for three to six hours each. We pulled our first nine cables.

Work continued throughout April, with a small group of volunteers working after school or nights once or twice a week plus Saturday, and with one or two volunteers working many additional afternoons, nights, and Sundays.

On Sunday, April 28, 1996, the volunteers completed termination of the patch panel and the last of the 50 (fifty) Category 5 cables.

At 3:30 PM on Wednesday, May 1, two professional cablers from Collins Control in Fort Collins brought their best test-equipment to test and certify our installation. By 5:15 PM, our new infrastructure was certified as 100% Category 5 compliant!

[Click here to view the floor plan with Category 5 information.]

Since the lead volunteer will not always be available at Mary Blair, the purpose of this handbook is to document the installation guidelines that allowed us to achieve 100% Category 5 compliance.

Obviously, this handbook should be consulted whenever any Category 5 cabling modification is planned or performed.

Less obviously, this handbook should also be consulted whenever any lighting or AC wiring changes are planned or performed.

INDUSTRY STANDARDS

All cables were UTP (unshielded twisted pair), 4 pair, 24 AWG, EIA/TIA 568, verified Category 5.

All terminations at the jacks and at the patch panel were T568B. (AKA AT&T 258A). The jacks and the patch panel were rated as Category 5.

All terminations at the jacks and at the patch panel used 110-style punch-downs.

In most classrooms, the existing IBM Baseband LAN jacks were replaced. The replacement jacks were 6-conductor USOC with 110-style punch-downs. No other modifications of any kind were made to the existing IBM Baseband LAN.

In one or two cases, a modem or voice jack was replaced. The replacement jacks were USOC jacks with 110-style punch-downs.

MBE STANDARDS

Cable designations:

Jack color codes:

The second cable (cable B) is always connected to a red jack.

The third cable (Cable C) is connected to a purple jack. (Only the media center has more than two cables at this time.)

The fourth cable (Cable D) is connected to a yellow jack.

Blue, red, purple, and yellow jacks are always rated as Category 5.

The rewired IBM Baseband LAN jacks are white.

The rewired voice-grade (voice, modem, or AT&T Spirit) jacks are ivory.

Patch-panel color codes and positions:

Patch panel ports for a given room are always adjacent to each other. The ports are always in order from left to right (blue, red, purple, yellow).

Note: This standard ordering is important for those who are colorblind.

Coverplate and jack positions:

Unused positions were always filled with ivory blanks.

The Blue jack, if present, is always in the upper left position.

The Red jack, if present, is always in the upper right position.

The White jack, if present, is always in the lower right position.

The Ivory jack, if present, is always in the lower left position.

In several cases, an existing box was mounted horizontally. In this case, the above position scheme was used when installing the jacks in the cover plate. Then the cover plate was rotated 90 degrees and installed over the box.

Note: This standard positioning is important for those who are colorblind.

Parts list:

• 41080-4IP 4-port wallplate, ivory
• 41080-6IP 6-port wallplate, ivory
• 41084-BIB Blank inserts, ivory
• 41108-RL5 Category 5 jack, blue
• 41108-RR5 Category 5 jack, red
• 41108-RP5 Category 5 jack, purple
• 41108-RY5 Category 5 jack, yellow
• 41106-RI6 USOC jack, 6P6C, ivory
• 41106-RW6 USOC jack, 6P6C, white
• 41777-IBB Surface Mount Box - 1.45" deep, ivory
• 49484-B24 24-port Category 5 patch panel, 568B, 110, black.

CATEGORY 5 CABLE LENGTH GUIDELINES

In an office environment, the 90/6/3 allocation is reasonable. In a 30' x 30' classroom, a 3 meter cable is often unreasonable.

An alternative is to tally the distance of each of the three components of the cabling system. The patch cable connected to the hub and the patch cable connected to the computer must be measured at 120% of their actual length. [Patch cables are more flexible than building wiring, but have poorer electrical characteristics.]

The longest cable run in MBE is currently about 255 feet. In practice, a 30 foot patch cable in the classroom should not strain the Category 5 distance limitations.

CATEGORY 5 CABLE ROUTING GUIDELINES

• Unlike ordinary telephone cable, Category 5 specifications do not permit a splice in the cable. If a cable is damaged, a completely new cable must be installed.
• Do not allow the sheath of Category 5 cable to be damaged. In particular, avoid pulling cable across rough surfaces such as concrete or sharp edges of angle-iron.
• The minimum bend radius of Category 5 cable is variously recommended at 2 to 4 inches. (Remember a circular loop would have a diameter twice the radius!) Observe the 4-inch minimum bend radius at all times except at the two points of termination. If possible, observe the 2-inch minimum bend radius at the jack and at the patch panel.
• Never allow a cable to be kinked while handling it. If a kink begins to form while pulling cables, STOP!
• When pulling cable up into the ceiling or around a corner, it is usually necessary to have a human "feed" the cable to prevent the minimum bend radius from being exceeded.
• Never route Category 5 cable within 18 inches of a flourescent light fixture.
• Never route Category 5 cable within a few feet of large motors or power transformers.
• When running Category 5 cable parallel to line voltage, always keep a separation of 5 inches or more, even if the line voltage is enclosed in conduit.
• When running Category 5 cable across line voltage, try to keep a separation of 5 inches or more. An occasional separation of slightly less than 5 inches is acceptable. In particular, avoid laying Category 5 cable directly across conduit containing line voltage.
• Make liberal use of "beam clamps" and "bridle rings" to route the cable where you want it to go, not where the cable would tend to go on its own.
• Category 5 cable should be essentially circular. When using cable ties on Category 5 cable, do not tighten the cable tie to the point that the cable deforms. As a general rule, the entire bundle of Category 5 cable that is tied should be able to slide freely back and forth inside the cable tie.
• Modern building codes preclude Category 5 cables from being tied to electrical conduit, water or steam pipes, air-ducts, drop-ceiling wires, etc. In general cables should be supported by structural components of the building such as steel beams. Tying to steel supports such as All-Thread, which are themselves attached to structural steel or concrete is also acceptable. Use two cable ties where necessary. (One cable tie firmly gripping the steel and a second cable tie. The second cable tie loosely holding the Category 5 cables.)
• Modern electrical and fire and safety codes require only UL-listed communications cable be used. Although we found some existing non-plenum rated cable in the west wing, we believe the entire south and west wings of Mary Blair Elementary require plenum-rated cable. (UL Type CMP or MPP are acceptable.)
• Where a bundle of cables must pass through a wall, including a firewall, install a chase: Use EMT or rigid metal conduit; install a set-screw connector on each end of the conduit; and install a nylon bushing on each end of the conduit. The sharp edge of a concrete-block wall or the sharp edge of an unbushed conduit can easily damage the Category 5 cables.
• Modern fire and safety codes require careful attention when a firewall is breached. We believe that nearly all of the previously installed communications cables (IBM Baseband LAN, telephone, cable TV, closed-circuit TV, fire-alarm, intercom, etc) pass through firewalls in a manner that does not comply with current codes.
• In all cases where new communications cable passes through a firewall, install a chase as described above, fill the chase not more than 40% full of cables, and install an airtight plug of Fire Stop caulk inside the conduit to fill the space not occupied by cables. Install an airtight bead or plug of Fire Stop caulk outside the conduit to fill the space between the conduit and the hole bored through the firewall. In the case of a 2-hour firewall, a minimum depth of 1 inch of Fire Stop caulk is required on each side of the firewall. In the case of a 1-hour firewall, a minimum depth of 1/2 inch of Fire Stop caulk is required on each side of the firewall.
• The National Electrical Code as well as the UL listing for Fire Stop caulk, specify that the chases cannot be filled over 40% full, by area. The volunteers installed 1.25" EMT, whose cross-sectional area is 1.50 sq in. [See 1993 NEC, Chapter 9.] Category 5 cable is approximately 0.2 inches in diameter, but varies slightly with manufacturer. Eighteen or fewer cables of 0.206 inch diameter may pass through a section of 1.25" EMT. Twenty or fewer cables of 0.195 inch diameter may pass through a section of 1.25" EMT.
• Please do not put anything through the chases installed for Category 5 cabling except additional Category 5 cables!

CATEGORY 5 JACK TERMINATION GUIDELINES

• Cable "A" is connected to the blue Category 5 jack.
• Cable "B" is connected to the red Category 5 jack.
• The sheath should be stripped back no more than 1/8" from the back of the jack.
• Leviton Category 5 jacks are marked with 568A and 568B color codes. Since we are using the 568B standard, follow the color code marked "B" on the jacks.
• Each pair should be untwisted as little as possible, and may not be untwisted more than 1/2" from the point of termination.
• Route the wires down the center of the channel in the jack. Each of the two wires of a pair should be as nearly the same length as possible.
• Do not damage wire or insulation while punching down other pairs. Suggest punching down the pair at the rear of the jack first, then the pair closer to the front, then the two pairs at the front, in either order.
• Avoid having the pairs cross each other more than necessary. Suggest rotating cable (or jack) before beginning punch-down to minimize pair crossings.
• Double-check that all 8 wires are fully punched down, trimmed, and colors are correct!
• Install strain reliefs.
• When installing cover plate, maintain the largest possible bend-radius.

USOC JACK TERMINATION GUIDELINES

• Remove cable from existing jack.
• Leviton USOC jacks are marked with color codes. Simply match color code on IBM Baseband LAN cable to color code on jack.
• Route the wires down the center of the channel in the jack.
• Do not damage wire or insulation while punching down other pairs. Suggest punching down the pair at the rear of the jack first, then the pair closer to the front.
• Double-check that all 4 wires are fully punched down, trimmed, and colors are correct!
• Install strain reliefs.

CATEGORY 5 PATCH PANEL TERMINATION GUIDELINES

• Plan the layout of the patch panel before you begin.
• "Comb" the cables as they drop from the ceiling. Suggest bundling groups of six cables corresponding to groups of six ports on the patch panel.
• Leave a reasonable "service loop" on each cable, in case it needs to be reterminated.
• Begin terminating with the topmost patch panel.
• For each patch panel, begin terminating at the side the cables are fed from. In our case, we unhinge the patch panels and terminate from left to right on the back of the patch panel, which is from high port number to low port number.
• Cut each cable to length, such that each cable connected to a single patch panel will follow the same service loop. Besides looking neat, the patch panel can be shifted up or down as necessary if new equipment is added at a future date.
• As a cable is terminated, lay it on top of the previously terminated cables on the back of the patch panel.
• The 110D connectors on the rear of the patch panel are color coded. Within each pair, Tip is to the left and Ring is to the right. Tip is the predominantly white wire.
• Each pair should extend to the right, and then gracefully curve up or down towards its termination. Avoid ultra-sharp bends and U-turns in the pairs.
• Each of the two wires of a pair should be as nearly the same length as possible.
• The sheath should be stripped back no more than necessary. Suggest stripping the sheath even with where the first pair will be punched down.
• Each pair should be untwisted as little as possible, and may not be untwisted more than 1/2" from the point of termination.
• Do not damage wire or insulation while punching down other pairs. Suggest punching down the pairs from left to right.
• Avoid having the pairs cross each other more than necessary. Suggest rotating cable before punching down each pair to minimize pair crossings.
• Double-check that all 8 wires are fully punched down, trimmed, and colors are correct!

HOW IMPORTANT ARE THE GUIDELINES?

A cable might pass, even with a few minor transgressions of these guidelines.

Our policy was to follow the guidelines, except in those few instances where it was extremely difficult to follow them. There are several instances, especially where only one or two cables are involved, where the cable routing guidelines were followed less rigorously.

FUTURE PLANS

The volunteers kept some cable on reserve in case of trouble with the testing. After the network was tested, but before the Fire Stop was installed, cables were run to room 207. Room 207 remains to be terminated and tested.

Room 210 is behind its own 1-hour firewall. This room remains to be cabled.

The multipurpose section of the building is behind its own 2-hour firewall. This includes the Music and Art rooms, which remain to be cabled.

The media center needs more ports. It may make sense to install a small hub in lieu of running a number of additional cables.

The only areas cabled were classrooms and the Media Center. Other areas may need to be cabled, but were not considered high priority.

COMPARISON WITH DISTRICT PLANS

More details regarding the cabling infrastructure of the schools are contained in the above report's Appendix B "Cyberlink Final Report -- March 1995".

We believe the category 5 cabling the volunteers installed is in perfect harmony with the goals of the Strategic Plan.

We also believe that aside from having a portion of the work done sooner at a fraction of the cost, the category 5 cabling is in close harmony with Appendix B and with Appendix H, the Tactical Implementation Analysis.

The District recognizes that the IBM Baseband LAN is hopelessly obsolete. For Mary Blair Elementary, the strategic plan recommends installation of two Category 5 cables plus one telephone cable into each classroom.

The strategic plan also recommends installation of Category 5 cables in virtually every area of the building, including the custodial office, the kitchen, and the boiler room.

Mary Blair Elementary is listed in Appendix B as being a "Phase 3" school. If ample funding had been available, MBE would have been cabled by June 1998. However, at the time of MBE's NetDay, funding was not available, and the cabling was already a year behind Appendix B's schedule.

The Board of Education is now (circa July 1996) considering a bond issue that would raise money for this and other purposes.

The total cost of cabling MBE is shown in the plan at $51K. Of this, approximately $33.5K is for cabling the 28 classrooms, and the balance is for cabling the Media Center and other areas of the building.

Of the $33.5K designated for cabling the 28 classrooms, $18.6K is for two Category 5 cables per classroom, and $14.9K is for a telephone line to each classroom.

At the time the Cyberlink report was prepared, there was a critical shortage of plenum-rated cable. Therefore, the Cyberlink estimates were for installing non-plenum cable in conduit. Since this shortage has abated, the volunteers chose to install plenum-rated cable without conduit.

The Cyberlink estimates did not include hubs.

Comparison of Costs at Other School Districts

The North Carolina NetDay '96 experts estimate their equivalent cost to be $2,250 per classroom.

The Category 5 portion of the MBE portion of the Thompson R2-J Plan works out to about $660 per classroom ($18.6K divided by 28 classrooms).

The MBE volunteers spent less than $125 per classroom, of which the majority of the funds came from the PTO and Student Council.

Telephone Lines to Each Classroom

Despite this, the volunteers did bring limited telephone service from the telephone room to the Category 5 patch panel. If a class needs telephone service for a particular lesson (for example for a distance-learning application or a modem connection), telephone service can be brought to that classroom via the patch panel for the duration of the lesson.

The Plan specifies that existing wiring should be reused wherever possible. Long term, the lead volunteer questions whether new telephone cables to each classroom are required.

Every classroom has an IBM Baseband LAN connection, which will be phased out eventually. Therefore, every classroom is already wired with two pairs of better-than-telephone grade cable.

Each classroom's Baseband cable connects to one of four IBM Baseband Hubs at one of three locations throughout the school. Each Baseband Hub can serve up to ten classrooms.

Why not run a 25-pair telephone cable (or five to ten 4-pair Category 3 cables) from the telephone room to the current location of each Baseband Hub. When the old baseband LAN is phased out, splice the old classroom baseband cables onto the new telephone cables.

Even if it is decided to run a separate telephone (or Category 3) cable from the telephone room to each individual classroom, the materials costs should be significantly less than the costs involved for the Category 5 cabling installed by the volunteers.