The photograph on the previous page shows a typical unit. The ventilated cover section lifts off the chassis leaving all
the internal parts accessible for maintenance and cleaning. A version without all of the ventilation slots is available for situations
where ingress of dust and liquids is a possibility.
The charger section is rated continuously at 30 Deg C ambient, and is a half-controlled thyristor system for single-phase
operation. A further control unit provides overvolt and alarmed shut-off of the charger should the output voltage go over a preset limit,
the output circuit being disconnected at the output contactor. A panel-mounted indicator shows whether the charger is connected
and charging or shut off, it also flashes if the disconnect function has been activated.
Output smoothing is standard on all our chargers, and the units will operate without battery if required, as stand alone power supplies.
Wiring is heavy-duty flexible stranded type with hexagon-crimped copper-tube terminals onto bolted connections throughout.
A three-phase unit is not offered currently, as there is little demand for such low outputs, but we would consider designing such a unit should
there be a significant requirement for such a system.
Indicators are provided for AC ON, CHARGE, INHIBIT, FAULT and CONNECT. No mains isolator and output control switches are provided as the
unit is intended for continuous 24 hour operation. These controls could be added to suit a specific requirement.
The main components including the transformer, choke, capacitors, thyristor stack and heatsink are all grouped inside
the main chassis for protection, and the whole assembly is covered by a 16g/1.5mm sheet steel body and cover. All parts are rated for long and continuous operation and
have some reserve in hand over and above their continuous rating requirements.
We recommend that batteries have no more than 4 X the rated output of the charger for a fast charge, or up to 10 X the rated output for slow and
overnight charging (40AH and 100AH for a 10A output charger.)
© Prepair Ltd 1990-2005 E&OE
TECHNICAL DESCRIPTION.
The CVT552 charger comprises a high-power, fully rated constant voltage charger, contained in a chassis and
casing which is designed to be wall mounted in a permanent installation. Fixing holes are pre-punched and cable entry is facilitated by
the pre-punched cable gland holes in the cover fixing brackets.
CONSTRUCTION
The system is built around a 2mm sheet steel chassis, to which all the main components are bolted.
(We do not use anything other than threaded fasteners, and all are either stainless steel or zinc plated)
The ventilated cover bolts onto the chassis at the top and bottom and either side of the control panel, and apart from a flying earth lead connection the cover can
be quickly removed.
AC POWER SUPPLY
The chargers are available with single phase input as standard, plus we can offer 110V or 415V AC (phase to phase) inputs as
options. Note that operation at 110V input effectively more than doubles the required AC supply current compared with 240V input.
BATTERY TYPES AND CAPACITIES
The chargers will operate on any type of battery that will accept the rated output of the charger. Typically, vented Lead-Acid and Nickel-Cadmium
types are usual, most applications comprise these battery types. The charger will also charge NIFE and Lithium-Ion batteries of suitable voltages and capacities.
CONNECTIONS.
The standard units have internal DIN rail mounted Klippon ST5 and SAK5 terminals.
TYPICAL USERS
The CVT552 wall units are in service throughout the UK on standby duty for various utilities and users. The voltage ranges available are shown below,
plus we are able to offer a customised output voltage and current range for OEM customers.
STANDARD VOLTAGES & OUTPUT CURRENTS
The chargers are available with the following standard outputs:
110V 20A
60V 25A
50V 30A
24V 30A
12V 50A
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