E
Approved
Ericsson Internal
PRODUCT SPECIFICATION
No.
Checked
Date
3 (4)
Prepared (also subject responsible if other)
EAB/FC/P Maria Rosendahl
1/1301 - BMR 659 Uen
Technical Specification
EN/LZT 146
381
R1C
Dec
2008
Rev
Reference
3
PKB
4302NG
Rosendahl
EAB/FC/P Maria
PI
Safety Specification
Intermediate Bus Converters,
Input
38-55
V,
42
A /
300
W
MICHORG
2008-06-03
B
© Ericsson Power Modules AB
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 Equipment
.
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
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.
On-board DC-DC converters are defined as component
power supplies. As components they cannot fully comply
with the provisions of any Safety requirements without
“Conditions of Acceptability”. 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 the board 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.
The galvanic isolation is verified in an electric strength test.
The test voltage (V
iso
) 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.
ERICSSON [ ERICSSON ]
