Ericsson Internal
PRODUCT SPECIFICATION 3 (4)
Prepared (also subject responsible if other) No.
SEC/S Marshall Wang
Approved Checked Date Rev Reference
2010-06-02 K T
The information and specifications in this technical
specification is believed to be correct at the time of
publication. However, no liability is accepted for
inaccuracies, printing errors or for any consequences
thereof. Ericsson AB reserves the right to change the
contents of this technical specification at any time without
prior notice.
Safety Specification
General information
Ericsson Power Modules DC/DC converters and DC/DC
regulators are designed in accordance with safety
standards IEC/EN/UL60950, Safety of Information
Technology Equip m ent.
IEC/EN/UL60950 contains requirements to prevent injury or
damage due to the following hazards:
• Electrical shock
• Energy hazards
• Fire
• Mechanical and heat hazards
• Radiation hazards
• Chemical hazards
On-board DC-DC converters and DC/DC regulators are
defined as component power supplies. As components
they cannot fully comply with the provisions of any Safety
requirements without “Conditions of Acceptability”.
Clearance between conductors and between conductive
parts of the component power supply and conductors on
the board in the final product must meet the applicable
Safety requirements. Certain conditions of acceptability
apply for component power supplies with limited stand-off
(see Mechanical Information for further information). It is
the responsibility of the installer to ensure that the final
product housing these components complies with the
requirements of all applicable Safety standards and
Directives for the final product.
Component power supplies for general use should comply
with the requirements in IEC60950, EN60950 and UL60950
“Safety of information technology equipment”.
There are other more product related standards, e.g.
IEEE802.3af “Ethernet LAN/MAN Data terminal equipment
power”, and ETS300132-2 “Power supply interface at the
input to telecommunications equipment; part 2: DC”, but all
of these standards are based on IEC/EN/UL60950 with
regards to safety.
Ericsson Power Modules DC/DC converters and DC/DC
regulators are UL60950 recognized and certified in
accordance with EN60950.
The flammability rating for all construction parts of the
products meets requirements for V-0 class material
according to IEC 60695-11-10.
The products should be installed in the end-use equipment,
in accordance with the requirements of the ultimate
application. Normally the output of the DC/DC converter is
considered as SELV (Safety Extra Low Voltage) and the
input source must be isolated by minimum Double or
Reinforced Insulation from the primary circuit (AC mains) in
accordance with IEC/EN/UL60950.
Isolated DC/DC converters
It is recommended that a slow blow fuse with a rating twice
the maximum input current per selected product be used at
the input of each DC/DC converter. If an input filter is used
in the circuit the fuse should be placed in front of the input
filter.
In the rare event of a component problem in the input filter
or in the DC/DC converter that imposes a short circuit on
the input source, this fuse will provide the following
functions:
• Isolate the faulty DC/DC converter from the input
power source so as not to affect the operation of
other parts of the system.
• Protect the distribution wiring from excessive
current and power loss thus preventing hazardous
overheating.
The galvanic isolation is verified in an electric strength test.
The test voltage (Viso) between input and output is
1500 Vdc or 2250 Vdc for 60 seconds (refer to product
specification).
Leakage current is less than 1 µA at nominal input voltage.
24 V DC systems
The input voltage to the DC/DC converter is SELV (Safety
Extra Low Voltage) and the output remains SELV under
normal and abnormal operating conditions.
48 and 60 V DC systems
If the input voltage to the DC/DC converter is 75 Vdc or
less, then the output remains SELV (Safety Extra Low
Voltage) under normal and abnormal operating conditions.
Single fault testing in the input power supply circuit should
be performed with the DC/DC converter connected to
demonstrate that the input voltage does not exceed
75 Vdc.
If the input power source circuit is a DC power system, the
source may be treated as a TNV2 circuit and testing has
demonstrated compliance with SELV limits and isolation
requirements equivalent to Basic Insulation in accordance
with IEC/EN/UL60950.
Non-isolated DC/DC regulators
The input voltage to the DC/DC regulator is SELV (Safety
Extra Low Voltage) and the output remains SELV under
normal and abnormal operating conditions.
E
PKM4000B series Intermediate Bus Converters
Input 36-75 V, Output up to 33 A / 400 W
EN/LZT 146 305 R6E January 2011
© Ericsson AB
Technical Specification