Comdial Dxp Plus Instructions Manual

							Installing The Switchable Power Supply In The
DXP Plus Common Equipment Cabinet
1.0 Introducing The Switchable Power Supply
This publication discusses the installation of the switchable IEC 950 approved 120/230 volt power supply
assembly for the DXPPlusmain and expansion common equipment cabinets. The voltage ranges of this power
supply assembly is as follows:
·90–129 VAC at 50/60 Hz
·200–254 VAC at 50 Hz
The power supply assembly is packed separately from the common equipment cabinet; therefore, you should
unpack and carefully inspect it for shipping damage and notify the shipper of any damages you find. Also, verify
that the package contains  all parts and accessories needed for proper installation and operation.
Refer to IMI66–105,Installation Instructions DXPPlusMain Cabinet Assemblyfor complete installation
instructions of the main DXP plus cabinet and to IMI66–106,Installation Instructions DXP Plus Expansion
Cabinet Assemblyfor complete installation instructions of the DXP plus expansion cabinet.
The power supply assembly is protected with a 6.3A, 250V slow-blow fuse. A replacement fuse must have the
same rating.
NOTE: Both the switchable power supply assembly employ electronic switching circuitry in their design. 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.
R
This manual has been developed by Comdial Corporation (the “Company”) and is intended for the use of its customers and service personnel. The information in this manual is subject to change without notice.
While every effort has been made to eliminate errors, the Company disclaims liability for any difficulties arising from the interpretation of the information contained herein.
The information contained herein does not purport to cover all details or variations in equipment nor to provide for every possible contingency to be met in connection with installation, operation, or maintenance.
Should further information be desired, or should particular problems arise which are not covered sufficiently for the purchaser’s purposes, contact Comdial, Inside Sales Department, Charlottesville, Virginia
22906.
Printed in U.S.A.IMI89-196.01
7/95 
						

							2.0 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. Use #10–12 or larger insulated solid copper grounding wire to connect the frame ground of the
expansion cabinet (available through the ground stud on the expansion cabinet’s side) to the frame ground of the
main common equipment cabinet. Use #6 or larger insulated solid copper grounding wire to  make the ground
connection from the main cabinet’s frame ground to earth ground.Keep this 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 DXPPlusand 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.
IMI89–196 Installing The Switchable Power Supply
2 – Installing The Switchable Power Supply 
						

							PLUS073
Grounding Terminal Two Grounding TerminalsGrounding Terminal
Grounding Terminal
Typical Earth Ground
No. 6 Solid Copper
Wire To Earth Ground
From Main Cabinet
No. 10 or 12 Solid Copper
Wire Between Cabinets
Grounding The System
Installing The Switchable Power Supply IMI89–196
Installing The Switchable Power Supply – 3 
						

							3.0 Matching The Source Voltage
The factory ships theswitchablepower supply set for 230 VAC operation. If you plan to operate the power supply
from a 120 VAC source, you must set the voltage selection switch for that input. The switch is located at the
upper right edge of the power supply assembly. Slide the switch actuator to the setting that matches the AC source
voltage available at the installation site.
CAUTION
Be sure that you set the power supply for the proper source voltage. An improper setting can result in
equipment damage.
Voltage Selector Switch
(Slide Actuator To Setting That
Matches The AC Source Volage)
PLUS076
Matching The Source Voltage
IMI89–196 Installing The Switchable Power Supply
4 – Installing The Switchable Power Supply 
						

							4.0 Installing The AC Power Plug
The line cord is terminated with a typical continental European plug matching the CEE 7/7 standard. If this plug
does not meet the site needs, you can install a plug of the proper type for your installation.
To install a line cord plug,
·familiarize yourself with the requirements for the plug that you plan to install on the unterminated line cord (the
illustration shows a typical continental European plug matching the CEE 7 standard),
·strip off the insulation from the line cord wires according to the requirements for your plug,
·open the plug and slide its outer shell onto the line cord,
·connect the ground, neutral, and line wires according to the requirements for your plug,
·if your plug includes a clamp, tighten it on the line cord,
·reassemble the plug,
Test the installation for open and short circuits using an ohm meter.
L3
L1
L2Neutral (Blue)
Ground (Green/Yellow)
Line (Brown)
L1, L2, and L3= strip length requirements
Inside Of PlugLine (Brown)
Ground (Green/Yellow)
Clamp
Neutral (Blue)
PLUS069
Installing A Typical Continental European AC Power Plug
Standard Wire Color
Power
SourceWire Color
Europe USA
LineBrown Black
Installing The Switchable Power Supply IMI89–196
Installing The Switchable Power Supply – 5 
						

							5.0 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 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 mating connector.
5. Remove the four #6 thread-forming screws from the hardware bag and secure the power supply assembly to
the equipment cabinet.
CAUTION
The power supply is fan cooled. If air flow to the fan is blocked or the fan is out of service for any reason,
the power supply can overheat. If the power supply overheats, theThermal Overloadindicator lights, and
the 36 VDC output voltage shuts off.
PLUS075
Typical Common Equipment Cabinet
Power
Supply
Assembly
Machine Screw
(4 Places)
Installing The Power Supply
IMI89–196 Installing The Switchable Power Supply
6 – Installing The Switchable Power Supply 
						

							6.0 Making The AC Power Connection
·For the main cabinet’s AC power connection, employ a dedicated 15 AMP circuit, with a third-wire ground and
supplied to a standard electrical outlet. Remember, this electrical outlet must be located within four feet of the
common equipment cabinet. Remember also, you may need to supply two 15 AMP dedicated electrical outlets,
each protected by its own circuit breaker, 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.
Plug-In
Power Line
Surge Protectors
Typical Earth
Ground Power
Cable
Two Dedicated
117 VAC 15 Amp
NEMA 5-15R
Electrical Outlets
With Third Wire
Ground
(Each Is Protected
By Its Own Circuit
Breaker.)
PLUS038
Two 15 AMP
Circuit Breakers
Ganged Together
Making The AC Connection
Installing The Switchable Power Supply IMI89–196
Installing The Switchable Power Supply – 7 
						

							7.0 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
For new installations, once you have measured the power supply voltages, turn off the AC power switch
and disconnect the AC line cord from the outlet. Leave the AC power disconnected until you have installed
the circuit boards in the equipment cabinet.
8.0 Identifying The Fuse
The power supply fuse is aslow-blowtype rated at 6.3 AMPS and 250 VOLTS. A replacement fuse must have the
same rating.
IMI89–196 Installing The Switchable Power Supply
8 – Installing The Switchable Power Supply 
						

							Power Supply Measurements
Measure Between Terminals
Measured Values
+ Voltmeter
Lead- Voltmeter
Lead
Pin 1 Pin 3
- 36 VDC +1.0V / -0V
Pin 5 Pin 7+ 5 VDC  +/-3 V
Pin 6 Pin 7- 5 VDC   +/-3 V
Pin 8 Pin 7
0 volts = normal operation
+ 5 V nominal = thermal overload
(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
PLUS070On/Off Switch
Fuse
6.3A, 250V
Slow Blow
Type
Reset Switch
(Press If Thermal Overload
Indicator Turns On)
Source Voltage Switch
Measuring The Power Supply Voltages
Installing The Switchable Power Supply IMI89–196
Installing The Switchable Power Supply – 9 
						

							Installing The Switchable External Battery Assembly On
The DXP Plus Digital Communications System
1.0 Introducing The External Battery Assembly
The external battery assembly is for use with the DXPPlusdigital communications system. 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. The assembly includes the
following items:
·Batteries: Five 6-volt, 50 ampere-hour, (Comdial product code BT000-141), charger unit and interface cables.
·Metal enclosure with wire harness, includes combination circuit breaker, on/off switch
Should the AC power to the system be interrupted, one BB480 external battery assembly provides the following
minimum power capability:
·1.0 hour of operation for a fully loaded system.
Calculate the minimum battery backup time provided by a battery assembly to a fully configured DXP Plus
system using the following formula:
T=Back-up time in hours
K=0.82 (Constant)
e=50 (ampere-hour capacity of battery assembly)
N=Total number of stations
Example:
Assume that you have installed a DXPPluswith three cabinets supporting 472 telephones and containing one line
board along with a battery assembly to provide back-up power.
During AC operation, the battery assembly accepts re-charging current to maintain the voltage potential of its
batteries at an operational level.
NOTE: The BB480 external battery assembly requires approximately 10 hours to completely re-charge to full
potential after it has been completely discharged and, in some cases, when initially installed.
T=Ke
1 + [(0.084) (N)]
T=(.82)(50) 41.0
1 + [(0.084) (472)]=
40.65= 1.0 Hour
R
This manual has been developed by Comdial Corporation (the “Company”) and is intended for the use of its customers and service personnel. The information in this manual is subject to change without notice.
While every effort has been made to eliminate errors, the Company disclaims liability for any difficulties arising from the interpretation of the information contained herein.
The information contained herein does not purport to cover all details or variations in equipment nor to provide for every possible contingency to be met in connection with installation, operation, or maintenance.
Should further information be desired, or should particular problems arise which are not covered sufficiently for the purchaser’s purposes, contact Comdial, Customer Service Department, Charlottesville, Virginia
22906.
Printed in U.S.A.IMI89–197.02
11/95