Nt8D46Ac Thermostat Harness - Nortel Meridian 1 Replacement Manual

Page 180 of 362

NT8D46AC Thermostat Harness

553-3001-520 Standard 16.00 April 2000
Replacing equipment
Use this procedure to replace the thermostat harness located in the top cap of
each column.
Module covers are not hinged; do not let go of the cover. Lift the cover
away from the module and set it out of your work area.
Removing equipment
1 Disconnect the system monitor from the circuit breaker system:
a Remove the grill on the rear of the column pedestal.
b Loosen the two screws on the system monitor and pull it out a few
inches.
If the system monitor is not unseated, column operation will shut down
when the thermostat harness is disconnected.
2 Disconnect power to the top cap:
a Remove the rear cover on the module below the top cap.
b Remove the I/O safety panel over the backplane.
c At the top of the rear of the module, disconnect the connector from
the module power harness.
d Disconnect the pin headers on connector J2 on the backplane;
disconnect the ribbon cable connector.
3 Remove the top cap:
— Remove air exhaust grills at the front and rear of the top cap (see
Figure 17). Pull forward on the two clips underneath the front edge
of each grill and lift up to remove the grill.
WARNING
CAUTION