Ericsson Internal
PRODUCT SPECIFICATION 3 (4)
Prepared (also subject responsible if other) No.
SEC/S Marshall Wang 1/1301-BMR 653 Uen
Approved Checked Date Rev Reference
SEC/D (Julia You) 2009-11-30 H
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 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
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.
EC61204-7 “Safety standard for power supplies",
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. PKM-B has the following stand-off (see
mechanical drawing for further information):
- 0.7 mm stand-off to tallest insulated part (signal
transformer's plastic housing)
- 0.7 mm stand-off to tallest unconnected (floating)
conductive part (the integrated transformer's and output
inductor's ferrite cores)
- 0.95 mm stand-off to tallest connected conductive part
(input- and output capacitors)
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 100 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 Ericsson Power Modules 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
PKM 4000B PI series Intermediate Bus Converters
Input 36-75 V, Output up to 33 A / 380 W
EN/LZT 146 305 R5C March 2010
© Ericsson AB
Technical Specification