ADTRAN 25 manual Overheating Trouble, Backplane and Cabinet Trouble

MAINTENANCE

Overheating Trouble

A clogged or dirty air filter can cause the cabinet to overheat. The cabinet air filter rests on the floor of the cabinet under the CP carrier. The air filter should be inspected on any service call and replaced as needed (with air filter comcode 845948348).

Caution: Check underneath cabinet for paper and other debris that could clog the air filter and cause the cabinet to overheat .

To replace the air filter, pinch it in the center and pull straight out.

Warning: To reduce risk of fire, air filter must be in place during o p e r a t i o n .

Backplane and Cabinet Trouble

The backplane provides power, TDM bus connections, and station and trunk interconnections. Each carrier has 12 universal slot positions. Any port CP can be installed in any slot. Connection to the corresponding stations or trunks is made through the backplane to the appropriate cross-connect field.

Danger: Hazardous voltages are present on some backplane

pins. Unplug the power cord and wait at least 5 minutes

before removing the rear cover.

Figure 4-9provides a rear view of the cabinet backplane (rear cover must be removed). Typical backplane pin designations are noted on Figure 4-9for pins 355, 254, and 056 located on slots 4, 3, and 1, respectively. Address plug locations for Cabinets 1, 2, and 3 are also noted. The address plug position assigned slot 8 is reserved for future use. Seven leads (BAO through BA6, see Figure 4-10)are tied to corresponding logic levels to uniquely identify each CP slot in the system, including multiple cabinet systems. The logic values on leads BA4 and BA5 are used to identify the cabinet (Cabinet 1, 2, or 3) and are tied through the cabinet address plugs to either +5 V dc or ground, as appropriate. Lead BA6 is tied to ground.

An address plug inserted on a cabinet’s backplane (pins 19 and 20) at slot 5 designates the cabinet as Cabinet 1, slot 6 = Cabinet 2, and slot 7 = Cabinet 3.

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