User Manual

MCA9129-90-A Installation & Service Manual

044-05060 Rev. C 3-6 July 2001November 2002

3-3.10 3-3.5 Fan Fail Indicator (FAN FAIL)

Red LED. When lit, indicates that either the upper front or rear one or more fans haves failed.

The lower front fan is not monitored for failure. If one fan fails, the FAN FAIL indicator will light If

the fan speed is below the threshold read at IOC2, 3, 6 or 7, the fan fail alarm LED will be illumi-

nated and a TTL high signal (+5Vdc) will be reported at pin 8 on the back plane connector. Fain

failure will not trigger a summary fault condition.

. If both fans fail, the FAN FAIL indicator will light, a timer is started, and the fan fail counter is in-

cremented. After five seconds the fault is analyzed. If the fault exists, the counter is incremented.

If the count equals 25 before the timer reaches 15 minutes, the MCPA will enter fault mode. Fault

mode will disable the MCPA. The FAN FAIL and LPA DISAB indicators will illuminate and a

summary fault will occur signaling the shelf that the MCPA is disabled. In fault mode the LED in-

dications are latched. Toggling the reset switch will enable the MCPA and clear the summary

alarm and latched indicators. If 15 minutes elapse before the counter reaches 25, the counter

and timer will reset to zero. Indicator is applicable to the large front and rear fans, not to the small

front fan.

Loop Indicator (LOOP FAIL)

Red LED. When lit, indicates that one of the loop control voltages has transitioned above or be-

low safe operating limits. If a loop fail condition occurs a timer is started and the loop fail counter

is incremented. After five seconds the fault is analyzed. If the fault exists, the counter is incre-

mented. If the count equals 25 before the timer reaches 15 minutes, the MCPA will enter fault

mode. Fault mode will disable the MCPA. The LOOP and LPA DISAB indicators will illuminate

and a summary fault will occur signaling the shelf that the MCPA is disabled. In fault mode the

LED indications are latched. Toggling the reset switch will enable the MCPA and clear the sum-

mary alarm and latched indicators. If 15 minutes elapse before the counter reaches 25, the

counter and timer will reset to zero.

3-3.12 Low Power Indicator (LOW PWR)

Red LED. When lit, indicates that the RF power output from the amplifier dropped -2dB (-1,

+0dB) below the average power output of all amplifier modules in the rack. If a low power condi-

tion occurs a timer is started and the low power fault counter is incremented. After five seconds

the fault is analyzed. If the fault exists, the counter is incremented. If the count equals 25 before

the timer reaches 15 minutes, the MCPA will enter fault mode. Fault mode will disable the MCPA.

The LOW PWR and LPA DISAB indicators will illuminate and a summary fault will occur signaling

the shelf that the MCPA is disabled. In fault mode the LED indications are latched. Toggling the

reset switch will enable the MCPA and clear the summary alarm and latched indicators. If 15 min-

utes elapse before the counter reaches 25, the counter and timer will reset to zero.

3-3.13 3-3.6 LPA Disable Indicator (LPA DISAB.) STATUS Indicator

Green/Red LED. When lit, indicates that the MCPA was disabled due to an internal fault or by

positioning the disable switch in the down position. or by the shelf performing the sleep mode

function. If a fault indicator does not accompany the LA DISAB indicator, the sleep mode function

is active.The status LED is green under normal operating conditions.

3.3.7 Power Circuit Breaker (OFF / ON)

Rocker style circuit breaker, which controls DC power to amplifier. The circuit breaker is rated for

100 amps, with amplifier thermal impact considered.