RFI SME240-1 2-20 User manual

SME240-1 2-20
Owner's Manual

Table of Contents
Introduction .................................................................. 1
Safety ............................................................................1
Operating Modes ......................................................... 1
Protection ..................................................................... 2
Battery LVD Operation ................................................ 2
Battery Charging Operational Requirements ................ 3
Battery Temperature Compensation ............................. 3
Thermal Protection ....................................................... 3
Alarm Output ............................................................... 4
Led Indicator ................................................................ 4
Output voltage .............................................................. 4
Dimension & Mounting ................................................. 5
Installation .................................................................... 6
Mounting Options ......................................................... 6
Connectors ................................................................... 6
Alarm/Temperature Sensor ............................................. 6
DC Power Output ........................................................... 6
Connection .................................................................. 7
Cabling ......................................................................... 7
Voltage Setting ............................................................... 7
Cooling ......................................................................... 8
Specifications ............................................................... 8
Approvals ...................................................................... 9
Copyright © RFI 2011
Disclaimer
RFI makes no claim as to the accuracy or suitability of the information contained in this manual or from any other
documentation. RFI accepts no liability for any loss or damage, which may occur as a result of improper or unsafe use of its
products.

READ T IS FIRST!
BEFORE INSTALLING T E SME240-1 2-20 CAREFULLY READ T E FOLLOWING
INSTRUCTIONS, ESPECIALLY T E SAFETY NOTES AND WARRANTY
CONDITIONS.
INTRODUCTION
The RFI SME240-1 2-20 (battery charger/eliminator) provides a power output of 280 watt at
1 3.6 Volts. The nominal input mains may be 220 V to 240 V and 50 z.
The SME240-1 2-20 has been designed specifically for telecommunications applications
demanding high reliability, low noise, fully automatic battery backup, battery protection and full
protection of the output. Many other applications will be able to take advantage of these
features which include:
• Light compact design
• igh Efficiency
• Battery over discharge protection with automatic reset
• igh reliability with conservative thermal design allowing continuous full load operation
with convection cooling
• Alarm for low mains and reverse battery connection
• User accessible output voltage adjustment
• Low noise output, ideal for telecommunications applications
• 3 modes of operation
• Convenient output connector
• Flexible mounting options
• Full protection for the power supply, load and battery
• Local technical support
1
Safety
Correct installation is the most critical factor in ensuring the safe use of the power supply. If
every consideration in the Installation section of this manual has been satisfied the power
supply will be safe to operate.
Operating Modes
The SME240-1 2-20 has three main operating modes:
1 . As a battery eliminator it may be used to power equipment requiring 1 2 V –1 4 V at 20 A. It
is fully protected against overload and short circuit as well as incorporating over voltage
protection.
2. As a lead acid battery charger it will provide safe and convenient method to restore
discharged batteries. Fully charged batteries can be left connected to the unit indefinitely
with no adverse effects on their lifetime.
3. The full features of the unit are realised when both a battery and a load are connected so
that it operates as a power supply with power fail protection. Under normal conditions an
internal switch connects the battery in parallel with the load. The average load must be less
than the capability of the power supply to ensure there is a remainder available to float
charge the battery.

2
When a mains failure occurs, the power supply no longer provides power. The battery
now supports the load without interruption of the load. Restoration of the mains restarts
the power supply which will resume support of the load and charging of the battery.
During extended mains failures the unit disconnects the battery before it becomes
excessively discharged. The battery is automatically reconnected when the mains
recovers. This feature contributes to long battery lifetime and allows unattended operation
of a system.
Protection
The power supply incorporates the following protection features
• Reverse polarity connection of the battery will not cause damage to the power supply or
the battery and the output load will remain unaffected.
• Electronic battery fusing is provided in series with battery connection to protect the load
and power supply when it is powered from the battery.
• Accurate current limit protection is provided for both load and battery. Automatic
recovery from short circuit is provided with no current tailing in short circuit operation.
• Over voltage protection provides shutdown of power supply.
• Inrush Surge limiting at turn on.
• OTP over temperature protection for blocked fuse incorrect install.
Battery LVD Operation
A low voltage disconnect (LVD) is provided to prevent deep discharge of the battery.
LVD Operation
When mains has failed and the battery is supporting the load, the battery must be
disconnected from the load if its voltage falls below the following levels:
Model Battery Disconnect Condition Validation time ±30%
(LVD_Disconnect)
SME240-1 2-20 1 0.25 V ±0.25 V 1 .8 sec
The battery will be connected to the charger/load output when its voltage rises above
the following levels:
Model Battery Connect Condition Validation time ± 30%
(LVD_Reconnect)
SME240-1 2-20 11 .90 ± 0.30 V 2.3 sec
The battery disconnect is incorporated into the Battery +ve line.
The BATTERY output has protection incorporated against a reversed battery connection.
A reversed battery is left disconnected so that the LOAD output can still run the load from
mains power. The quiescent current drain on the battery when the main has failed is less
than 3 mA.

3
Battery Temperature Compensation
When the optional battery temperature sensor TMS1 01 is connected the output voltage will
be adjusted by the amount shown in the table below to maintain the optimal battery
changing voltage.
Temperature Compensation Model Temperature Compensation
(Reference Temperature = 20 °C)
SME240-1 2-20 -1 8 mV/C
Thermal Protection
A thermally controlled fan is used to maintain temperatures a non latching thermal shut
down is used to protect against overheating due to:
• Use in excessive ambient temperature
• Output overload
• Fan failure/blockage
• Other fault conditions
Battery Charging Operational requirements
Trickle Charge
When mains is present but the battery voltage is below the LVD Connect voltage, the
battery is trickle charged circuit that limits the charging current to a trickle charge current
of 1 .0A ± 20%.
Vfloat
During Vfloat mode the battery is charged at 1 0 A until the float voltage is reached.
Vequalise
Periodic equalise at 1 4.25 V is provided for 1 5 minutes every 24 ours.
Battery Charge modes
To maintain the battery in a good state of health a charging algorithm is to be used to
ensure that the correct voltages are applied to the battery terminals at the appropriate
times throughout it’s usage cycle.
The voltages for each Mode at 20°C is:
Float Voltage Equalise Voltage
1 3.65 ± 2% 1 4.05 ± 2%