Comdial Dxp Plus Instructions Manual

							1.4 Mounting The Common Equipment Cabinet
1. Unpack and carefully inspect all equipment for shipping damage.  Notify the shipper immediately of any
damages found. Verify that the packages contain all parts and accessories needed for proper installation and
operation.
NOTE: The following instructions describe how to mount the main cabinet using a backboard; however, you can
mount the cabinet on a standard 23–inch equipment rack if you wish.
2. Choose a place at the mounting location where the backboard will bridge underlying wall studs, and securely
attach a suitable backboard to the mounting surface. (Suitable backboards are available commercially or you
can construct one out of 3/4-inch plywood.) You must drive the hardware that secures the backboard to the
mounting surface into the underlying wall studs instead of just into the wall material alone.
3. Refer to the illustration for the locating dimensions required for the mounting screws, and mark their locations
on the backboard. You must attach the main common equipment cabinet vertically to the backboard.
4. Drill holes in the backboard of a proper size to accommodate the hardware being used.
5. Insert the two top screws into the backboard and tighten them to within approximately 1/8-inch of the surface.
6. Hang the cabinet on the top screws using the top mounting holes in the rear mounting flange of the cabinet.
Note that these holes are elongated with an enlargement at one end. This feature allows the cabinet to slide
down on the screws to secure the mounting when the cabinet is hung on them.
7. Use the openings for the middle and lower set of mounting screws as a guide, and mark the location for the
remaining screws.
8. Lift the cabinet from the top screws and set it aside while preparing the holes for the remaining screws.
9. Rehang the cabinet as discussed in step 6.
10. Insert the middle and lower screws into the backboard and tighten them to within approximately 1/8-inch of
the surface.
Shipping screws attach the front panel to the main cabinet. These screws are in addition to the two retaining
screws located at the lower corners of the panel. Remove and store the shipping screws. You will not need them to
re-attach the panel to the cabinet after you have installed the power supply assembly, circuit boards, and wiring;
however, you will need them to secure the panel in place if  you should later transport the cabinet to a new
location.
After you remove the screws, pivot the front panel upward until you can unhook the panel hangers from the slots
in the cabinet top. To re-attach the front panel, pivot it upward so that you can hook the panel hangers into the
slots at the top of the cabinet, and then pivot the panel down in place. Install the two retaining screws at the
bottom right-hand and left-hand corners of the panel to secure it to the cabinet.
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							48
12 3/4
10 1/2
10 1/222 5/16
Retaining
Screws
(Two Places) Typical Backboard
48 X 96 X 3/4 Plywood Sheet
PLUS025
Mounting The Common Equipment Cabinet
Installing The DXP Plus Main Cabinet IMI66–105
Installing The DXP Plus Main Cabinet – 3 
						

							1.5 Understanding System Grounding Requirements
Transient voltage spikes, if induced onto CO or CENTREX lines, can travel through the cable and into the
common equipment. The telephone company offers basic protection against this condition but it is usually
designed to protect the central office circuits. While it will also provide some protection to the common
equipment, you should not rely upon it for total protection. To help ensure that external over-voltage surges do not
damage the system, you should install and properly ground primary protection devices, such as gas discharge
tubes or similar devices, on all lines. While the line boards have internal secondary surge protection on all line
ports, in order for this protection to be effective, youMUSTconnect the common equipment cabinet to a reliable,
effective earth ground.
Proper DXP grounding is necessary for trouble-free operation and personnel safety. The DXPPlushas the
following three types of grounds:
·Service Ground—a neutral power line wire that is connected to the ground bus in the premises’ AC power
panel,
·System Ground—a non-current carrying power line wire that is connected to the ground bus in the premises’
AC power panel,
·Frame Ground—a low impedance conductor that places the common equipment cabinet at reference ground
potential. The frame ground provides the greatest safety by limiting electrical potential between non-current
carrying parts of the system. The common equipment cabinet provides a ground stud on its cabinet for access to
its frame ground.
Effective grounding requires that you connect the frame ground to a good earth ground. A good earth ground is
one such as the ground bus in the premises’ AC power panel or a public metallic cold water pipe at a point
immediately at its entrance to the premises and ahead of any meters, pumps, or insulating sections that have been
added for vibration reduction. Avoid using the premises’ structural steel frame as it may not be at earth ground
potential. Make the ground connection with #6 or larger insulated, solid copper grounding wire.Keep the ground
wire separate from the three-wire AC line cord, do not splice it, and keep it as short as possible.
The impedance of the wiring between the DXP and the earth ground must not exceed 0.25 ohms and the
impedance between the earth ground and the power company’s reference standard ground must not exceed 5
ohms. Use an acceptable low impedance measuring device to measure the impedance of these paths. The #6 or
larger wire size will minimize the wiring impedance; however, if the impedance between earth ground and the
power company’s standard reference ground exceeds 5 ohms, contact the local power company. The ground path
must always be of sufficient current-carrying capacity to prevent a build up of voltages that may result in circuit
noise, hazard to personnel, or equipment damage.
Be sure that all of the ground connections are visible for inspection and maintenance. Tag all of the ground
connections with a sign that reads:Do Not Remove Or Disconnect.
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							No. 6 Solid
Copper Wire Grounding
Terminal
Typical Earth
Ground
PLUS040
Grounding The System
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							2.0 Installing The Power Supply
NOTE: The common equipment cabinet employs an electronic switching power supply. During operation, power
supplies of this type generate an audible sound from their switching regulators.  This sound is normal and
is not an indication that the power supply is operating improperly.
Install the power supply assembly in the common equipment cabinet per the following discussion and illustration.
1. Be sure to ground the common equipment cabinet per the instructions in the previous paragraph before
installing the power supply assembly.
2. Remove the power supply assembly from the carton. Be sure to save the small bag containing the mounting
hardware.
3. Slide the power supply assembly into the opening at the top right side of the common equipment main cabinet
until the assembly’s front panel contacts the side of the cabinet.
4. Locate the power cable routed from the backplane and connect it to the power supply’s connector.
5. Remove the #6 thread-forming screws from the hardware bag and secure the assembly to the cabinet.
6. The supplied power supply assembly accessories include a ferrite collar. Snap this collar around the AC
power cord to provide protection against radio frequency interference.
PLUS075
Typical Common Equipment Cabinet
Power
Supply
Assembly
Machine Screw
(4 Places)
Installing The Power Supply
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							2.1 Making The AC Power Connection
·For the main cabinet’s AC power connection, employ a dedicated 117 VAC 15 AMP circuit, with a third-wire
ground, supplied to a standard electrical outlet (NEMA 5-15R). Remember, this electrical outlet must be
located within four feet of the common equipment cabinet. Remember also, you must supply two dedicated
electrical outlets if you plan to later install expansion cabinets.
NOTE: If you install the optional battery back-up assembly, you can use this same outlet to supply AC power to
that assembly’s battery charger.
·To provide protection against surges and spikes that may appear on the AC line, install a plug-in power line
surge protector between the AC power cord of the installed equipment and the AC outlet..
CAUTION
DO NOT attach or secure the line cord to the surface of the mounting location in any manner.
Typical Earth
Ground Power
Cable
PLUS041
Two 15 AMP
Circuit Breakers
Ganged Together
Plug-In
Power Line
Surge Protectors
Two Dedicated
117 VAC 15 Amp
NEMA 5-15R
Electrical Outlets
With Third Wire
Ground
(Each Is Protected
By Its Own Circuit
Breaker.)
Making The AC Power Connections
Installing The DXP Plus Main Cabinet IMI66–105
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							2.2 Measuring The Power Supply Voltages
If you need to measure power supply voltages, you can do so at the DC voltage connector. Measure the power
under the following conditions:
·AC line cord connected to the AC outlet,
·DC power cable disconnected from power supply’s DC voltage connector,
·AC power switch turned on.
Measurement details are shown in the illustration.
CAUTION
Once you have measured the power supply voltages, turn off the AC power switch and disconnect the AC
line cord from the AC outlet. Leave the AC power disconnected until you have installed the circuit boards
in the main cabinet.
2.3 Identifying The Fuse
The power supply fuse is aslow-blowtype rated at 8 AMPS and 250 VOLTS. A replacement fuse must have the
same rating.
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							Measuring The Power Supply Voltages
Power Supply Measurements
Measure Between Terminals
Measured Values
+ Voltmeter
Lead- Voltmeter
Lead
Pin 1 Pin 3 - 36 VDC +/- 1.0V
Pin 5 Pin 7 + 5 VDC +/- .3 V
Pin 6 Pin 7 - 5 VDC +/- .3 V
Pin 8 Pin 70 volts = normal operation
+ 5 V nominal = thermal overload condition
(press Reset switch)
On = -36 VDC
On = +5 VDC
On = -5 VDC
On = Thermal Overload
On = Battery Backup Connected
Pins 1 & 2 = -36 V Ground
Pins 3 & 4 = -36 VDC
Pin 5 = +5 VDC
Pin 6 = -5 VDC
Pin 7 = Digital & Analog Ground
Pin 8 =Thermal Overload Signal
On/Off
Switch
Fuse
8A, 250V
Slow Blow
Type
Reset Switch
(Press If Thermal Overload
Indicator Turns On)
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							3.0 Installing Circuit Boards In The Main Cabinet
CAUTION
Circuit boards for the DXP Plus system are susceptible to damage caused by electrostatic discharge, and
you must keep this fact in mind as you handle the circuit boards. Refer to the Comdial publication
IMI01-005,Handling Of Electrostatically Sensitive Components, for general information. Specific
handling precautions are also included in this installation instruction.
Each circuit board is supplied in a static protection bag. Do not open a static protection bag prior to board
installation time.
The board slots are keyed so that only those boards that will operate from a particular slot will plug into that slot.
The main cabinet provides unique slots for the CPU board, the services board, and the interface board for the main
cabinet). The remaining board slots are universal and will accept auxiliary boards, line boards, or station boards .
This publication provides installation instructions for the CPU and services boards. Since you will install line and
station boards as well as auxiliary boards and other optional circuit boards on an as needed basis, each of these
boards include its own installation instruction for your reference.
3.1 Creating A Static Safe Work Area
When servicing the common equipment cabinet at the installation location, it is a good practice to place a
conductive mat in front of the cabinet area and ground the mat to a good earth ground. (The third wire ground of
the AC power line is also an acceptable grounding point.) The grounded conductive mat provides a safe static
electric discharge path.
When removing the common equipment cabinet from the installation location for servicing, it is a good practice to
prepare a static-safe work area on which to place the cabinet.
You should supply yourself with a static discharge wrist strap, and wear it every time you handle electronic circuit
boards either at the cabinet mounting location or at your work area.
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							Typical Earth
Ground
Static
Wrist
Strap
ESD Protective
Mat ESD Protective
Mat
ESD Protective
Worksurface
Static 2
Common Point Ground
Creating A Static Safe Work Area
Backboard
Earth
Ground 1 Meg Ohm
Resister Conductive
MatStatic Discharge
Wrist Stap Common
Equipment
Cabinet
PLUS034
Providing Static Protection At The Cabinet Mounting Location
Installing The DXP Plus Main Cabinet IMI66–105
Installing The DXP Plus Main Cabinet – 11