Tma External Alarms Interfaces

7/30/2019 Tma External Alarms Interfaces

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Company Confidential

1 2005 Nokia V1-Filename.ppt / yyyy-mm-dd / Initials

TMA EXTERNAL ALARMS INTERFACES

TMA TYPE IN NETWORK

1. POWER WAVE TMA

2. ANDREW TMA


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TMA POWER WAVE


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FOR POWER WAVE TMA

To install the Bias Tee unit to the IAKx antenna box:

Before the installation of the Bias Tee to the antenna box, install the Bias Tee, thepower supply and the optional monitoring cables for the VSWR antenna.

1. Unpack the unit from its protective package and check for physical

damage.

2. Connect the power supply and the optional monitoring cables (for the

VSWR antenna) from the Bias Tee to the Bias Tee interface. The interface

is located on the top of the cabinet.

3. Install and tighten the Bias Tee to the connector of the antenna box.

4. Repeat step 1 through step 3 for each additional Bias Tee unit.


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Bias Tee power connection


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PDU

A functional block diagram of the PDU is shown in Figure. The PDU converts the

input DC power (+24VDC or -48 VDC) into an intermediate voltage level using a DCDC

converter. The intermediate voltage bus is then split into 6 outputs. Each output

is individually fused and regulated down to +12 VDC. A current monitoring circuit at

the output of each voltage regulator provides TMA alarm monitoring by sensing the

operating current of the TMA. The TMA operating current is measured and

compared against a specified set of thresholds (current window). If the measuredcurrent consumption falls within the current window, the TMA is declared to be

operating normally. If the TMA current consumption falls outside the current window,

the TMA is declared to be failed and an alarm condition is declared for that TMA.


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ALARM CONNECTION IN PDU

The Power cable connects the PDU to a +24VDC or -48VDC power circuit in the

BTS, depending on the model of the PDU. The PDU power circuit should be

protected by a circuit breaker. The 2-wire Power cable carries the DC voltage and

common return lines from the BTS to the PDU. The PDU DC power input is polarity

protected. If the Input LED does not illuminate when the PDU power is turned on,

reverse the polarity of the DC power connections at the BTS.

The Alarm cabledelivers the PDU summary fault information to an External Alarm

Interface (EAI) in the BTS. The alarm output is an insulated form C contact with all

three terminals available for use. It is recommended to use the Common and

Normally Open terminals of the summary fault relay when connecting the summary

alarm to the EAI. Loss of continuity between these terminals indicates that an alarm

condition, loss of PDU power, or detachment of the Alarm cable has occurred. The

Common and Normally Closed terminals can be used if the EAI requires a closed

contact closure in the event of an alarm.


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Alarm Relay Terminal Alarm Cable Color Code

Common -------White

Normally Closed --------Brown

Normally Open --------Blue


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TROUBLESHOOTING

Symptom Possible Cause(s)

DC Input LED not lluminated

Check that PDU power switch is in the ON position.

Check cable connections.

Check input voltage to PDU.

Power connections reversed.

Switch the polarity of the power connections.

TMA (DCoutput) alarm

Check Bias Tee harness connections at the PDU and Bias Tee(s) Can be caused by a spurious alarm. Reset the alarm toggle switch

for the output and re-enable it to see if the alarm will clear. If not,there is a problem with the DC path to the TMA (cables, Bias Tee) or

a TMA failure

PDU alarm but no BTS alarmCheck the connection of the alarm cable to the BTS. If the connections are OK, there could be a failure of the summary alarm

relay in the PDU. This can be verified by measuring continuity between the white and blue (NC contact) alarm cable wires at the

BTS. In an alarm condition, there should be no continuity between these two wires.

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Tma External Alarms Interfaces