NEC nd-20292 manual Or Higher, Common Control, Cpu-Eb Cpu-Ec, Level ETU

ND-20292

CHAPTER 2

APRIL, 1990

Install the wall mounting metal brackets as shown in Figure 200-11, using the four locally provided fasteners.

Using the open slots provided on the back panel of the CCU, mount the CCU to the knobs of the upper bracket and onto the base panel. Ensure the upper bracket knobs are fully seated within the open slots of the CCU. Tighten the screws from above the CCU to securely attach the CCU to the upper bracket knobs, install the two screws shown in Figure 200-12.

240.4	COMMON		CONTROL		ETUs
A. CPU-E,		CPU-EB(	),	CPU-EC(	) OR HIGHER	: 3
REVISION		LEVEL		ETU		2

Prior to programming the system data, Switch 2 (SW2) must be set to the ON position to allow memory

content retention, in case of a power failure or

brownout. Failure to activate the backup battery

I.Install the top panel onto the top CCU and secure with the screws removed in step C.

OFF

240.3NOTES FOR ETU INSTALLATION

A.To prevent accidental damage to equipment, it is

recommended that power be OFF during

installation and maintenance, unless this will seriously inconvenience the user.

B.The ETUs used in this system make extensive use

of CMOS technology. Extreme care must be

taken to avoid static discharge when handling ETUs.

C.A switch is provided on the interface ETUs to

protect circuitry from any damage during installation with system power ON.

D.The component side of ETUs must face the right side of the CCU when installed. (Viewed from the front as shown in Figure 200-16).

Figure 200-17 CPU-E( ) or CPU-EB( ) Switch Layout

circuit (SW2 ON) will result in the system data returning to default values and loss of Speed Dialing, Callback Request, Message Waiting, Clock/Calendar, station and trunk Group Name Assignments, etc., if a power failure or brownout occurs.

Anytime a CPU-E( ) ETU is installed, the system CZockK!ulendar must be set. This also applies when battery backup fails for any reason. This procedure is

Figure 200-16 Installing ETUs

200 - 22